Frequently Asked Questions

Hip Replacement Explanations

Total Hip Replacement: Introduction

We have developed this website to allow patients to educate themselves about hip and knee replacement. Tremendous advances have been made in these fields since I trained at Johns Hopkins over 25 years ago. Vigorous scientific debate continues as orthopedic surgeons strive to continue to advance the success of joint replacement. Sticking with “proven” treatments sounds good, but all proven treatments 25 years ago have been improved upon and have fallen by the wayside.

On the other hand, when we try to advance technology, we sometimes take 2 steps forward and one step back. No scientific studies are ideal, especially when surgical practice is concerned. A surgeon must evaluate studies and form an educated opinion about what is best through the lens of his personal education training and experience.

If we maintain careful follow-up on our patients and evaluate the data critically, we will be able to constantly improve much more than by just reading scientific papers and attending meetings. Specialist surgeons who perform large volumes of surgery and carefully scrutinize their data are typically the highest performers. The purpose of this website is to transmit my opinion backed up by my data so that patients can make an informed decision prior to surgery.

I have little interest in “proven” treatments. Instead I am always trying to incorporate the latest advances in my treatment protocols. As much as possible I like to stick to protocols that are occasionally altered according to identified patients needs or desires.

My biases are hip resurfacing, uncemented fixation, large metal bearings, minimally invasive surgery, and custom implants.

What Is Arthritis Of The Hip?

The hip joint is a deep ‘ball and socket’ joint that connects the leg to the pelvis. Confusion about the location of this joint is common. In common everyday usage, the term “hip” is applied to a bony ridge in the pelvis which is more accurately termed “iliac crest”, (eg., I carried the baby on my “hip”).

The hip is actually a joint that is located much lower. It can be found in the location of the groin crease where the leg attaches to the pelvis.

The ball of the hip joint is the “femoral head” which rests within the socket “acetabulum” of the pelvic bone. The surface of both the ball and socket is covered with a 3-4 millimeter thick layer of cartilage. The cartilage that lines the hip is an exceptional material. It is smoother than any man-made bearing. The cartilage has no nerve endings in it and, therefore, any motion between cartilaginous surfaces does not cause pain.

In a patient with arthritis, the cartilage wears away; debris is generated, producing pain. As the cartilage wears away, bone becomes exposed. The underlying bone does have nerve endings in it and is not a good bearing material. As the exposed bone ends rub against each other the nerve receptors in the bone are stimulated. This results in a greater pain sensation. Bone on bone pain is usually severe; the only solution at this point is some type of hip replacement.

You do not have to lose all of your cartilage in your joint to have severe pain, you just have to wear a section of the cartilage on both sides of the joint through. Often patients are told: “ you still have some cartilage left, so you don’t need an operation”. This, of course, is not true.

Types of Arthritis

There are many types of arthritis that may lead to degeneration of the hip joint. The most common form is osteoarthritis. It is not always known why some people will have worn out their joints at age 40 while others still have normal cartilage at age 70.

Most patients who have severe hip arthritis at an early age have some underlying deformity of the hip; the most common in young men is cam FAI (cam type femoral acetabular impingement), while dysplasia is the most common deformity in young women. However, genetic factors that determine the quality of cartilage and level of activity may also play a role. In my experience 80% of men under 55 have cam FAI and 30% of women under 55 have dysplasia.

Types of Arthritis

  • osteoarthritis
    • cam FAI
    • pincer FAI
      • profunda acetabulum
      • protrusio acetabulum
      • acetabular retroversion
  • post traumatic (following fracture or dislocation)
  • rheumatoid arthritis
  • other inflammatory arthritis (AS, IBD, Psoriatic)
  • osteonecrosis (avascular necrosis,) or Legg Perthes disease (bone collapse due to loss of blood supply)
  • congenital dysplasia (child with hip deformity)
  • SCFE (slipped growth plate)

The progression of arthritis from its earliest mild stages to its most severe crippling form is usually gradual. Initially, the pain occurs only after higher levels of activity. Later, it progresses and may become present at rest as well. Physical disability includes limp, muscle spasm, limited walking ability, decreased motion and stiffness, need for a cane, walker or even a wheelchair. The level of symptoms may fluctuate, but, generally, they worsen with time.

During its early stages, usually, arthritis can be treated with medication, supportive devices and modification of activities. However, as the cartilage on both sides of the joint wears away completely and the bone rubs on the bone, the arthritis has become “severe”. At this stage, placing a new artificial lining or surface on the joint (hip replacement) is usually the only effective way to relieve the symptoms adequately. Although there are many treatments that can lessen the symptoms of arthritis, there is no scientific evidence for any treatment to prevent further cartilage damage or to regenerate lost cartilage.

Non-Operative Treatment

Click on a heading to learn more about each of the non-operative treatment options out there for hip arthritis.

Activity Modification

Most commonly, arthritis is a “wear and tear” process; once a joint shows signs of significant degeneration, the more stress it is subjected to, the more it degenerates. Let me use the analogy of a tire on a car. If the tread is thin and worn, it will not last very long driving the car back and forth daily on a long commute. On the other hand, putting the car up on blocks preserves the tires, but makes the car useless to you. As you can see, the appropriate amount of activity modification is a very individual decision based on common sense.

As a general guideline, low stress activities that are usually tolerated well are short distance walking, exercise bicycle, swimming and water aerobics. High stress activities (these are not advised) would include jumping, jogging, long distance walking (> 1 mile) or heavy lifting. However, I have operated on many patients who don’t meet the traditional requirements for activity limitation.

With the improvement of surgical techniques and implants, I now think it is reasonable to replace hips so active patients can return to high-level activity such as running. An individual must weigh the risks of surgery against his/her desire to participate in sports or heavy work.

Weight Loss

Weight loss will also decrease the stress on a joint. Because of the muscles acting across the hip joint, normal walking causes a force across the hip approximately three to five times the body weight. Therefore, if you are 20 pounds overweight, the force across the hip is increased by 100 pounds. Even small amounts of weight loss will decrease the force about the hip, slow down the destruction of the hip joint and decrease pain.

Supportive Device

Cane, Crutch, Walker

Another way to decrease the force is to use a cane or crutch in the opposite hand. This decreases the required muscle function about the hip during walking and reduces the force on the hip by several hundred pounds. Braces are not effective in the treatment of hip arthritis.


Exercise is useful mainly to maintain muscle tone and range of motion. Isometric exercises and gentle range of motion exercises should be sufficient. Because arthritis is often a problem of “wear and tear”, vigorous exercises and the use of weights only results in further deterioration of the joint. Vigorous physical therapy, aggressive stretching and chiropractic manipulation usually worsen the symptoms.


Heat is also helpful to decrease stiffness and relieve pain. Superficial heat, such as provided by liniments and ointments, etc., do not deliver heat deep enough to be beneficial. The best is a hot water bottle or hot packs because the temperature can be controlled and they deliver a significant amount of heat deep into the joint. Use of a heated whirlpool or spa may also be helpful. Use of a heating pad can be helpful, but care must be taken to avoid burning the skin.


Glucosamine, sometimes in combination with Chondroitin, is an over the counter remedy that may relieve the pain of mild arthritis. Large scientific studies have shown conflicting results when judging symptom relief. It is not effective for severe arthritis (bone on bone).

However, it is often advertised as a treatment to rebuild lost cartilage —there is no scientific evidence for this claim. It does take 2-3 months of regular use of this material before it “gets into your system” and relieves arthritis pain.

If you notice no improvement in your symptoms after 2-3 months, it is probably not worthwhile to continue using this supplement. The usual recommended dosage is 1500 milligrams per day.


Tylenol is a very effective and safe pain reliever for the treatment of arthritis. It may be taken in conjunction with anti-inflammatory medications for added benefit. If taken on a regular and prolonged basis, regular check ups and lab tests by your internist are recommended. The maximum daily dosage in healthy adults is 3000mg. If you drink more than 1-2 alcoholic drinks daily, you should use less to avoid injuring your liver.

Non-steroidal Anti-inflammatory Medications (NSAIDS)

The use of non-steroidal anti-inflammatory medications (NSAIDS) is also an important treatment. Aspirin is the most commonly used anti-inflammatory medication, but many people cannot take it because of either allergy or gastrointestinal difficulties. There are many aspirin substitutes that are currently on the market but are significantly more expensive than aspirin. None of them have been shown to work any better than aspirin but they do have less side effects and more convenient dosage frequencies.

There are probably 25-30 of these types of medication on the market today. Each company claims superior effectiveness of their own brand. Sometimes one brand, as opposed to another, may seem to work better for one individual. However, generally speaking, they are all equally effective. The newer brands are usually advertised more vigorously and carry a higher price tag.

The earlier brands (Ibuprofen, Naproxen) are no longer under patent and can be purchased much more inexpensively and often at lower doses as an over-the-counter formulation. Sometimes, for unclear reasons, one may work better for an individual. However, if you have tried 2-3 of these and have inadequate relief, there is no value in testing others. The most common side effects of these are gastrointestinal (GI) irritation and bleeding. Rarely kidney or liver damage can occur.

Celebrex is a unique “cox 2” inhibitor. Its efficacy in treating arthritis pain is no different than all of the other NSAIDS. However, this drug is much less likely to cause GI irritation or bleeding than the other NSAIDS. This drug also does not interfere with platelet clotting function and therefore can be safely taken by patients using anticoagulant medicines (blood thinners). It also does not interfere with the therapeutic anti-platelet action of aspirin like the other NSAIDS do. Therefore, patients who are taking aspirin to prevent heart attacks and strokes may be better off taking celebrex rather than other NSAIDS.

There were two other “cox2” inhibitors previously on the market, which were recalled by the FDA. Vioxx was found to have a higher rate of cardiac complications than other NSAIDS. Bextra rarely caused a severe skin reaction called Stevens-Johnson syndrome. Although Celebrex is also a “cox 2” inhibitor, it causes no more cardiac problems than other NSAIDS and may well be safer than other NSAIDS in patients who need to take aspirin for clot prevention.

Celebrex is still patented; therefore it costs much more (approximately $100 per month) than other NSAIDS. Despite its proven better safety, insurance companies often place pressure on patients to use a less safe option. If you can’t afford celebrex, Mobic is the closest substitute as a mixed cox1/cox2 inhibitor. It is available as a cheap generic.

Other combination medicines including an NSAID plus a stomach protector are now available. Another strategy is to use over-the-counter prilosec as a stomach protector.

Steroid Injections

Steroid injections into joints can give temporary relief. If the joint destruction is not too severe, several months of relief can sometimes be achieved. Hip injection is difficult and costly; it is done under x-ray control. A dose pack of oral steroid can also give temporary relief. But the side effects of long-term steroids are severe and therefore oral steroids are not advised for most arthritis patients.

Visco supplementation

Visco supplementation injections seem to have a similar effect as steroid injections, but they are much more expensive and often require multiple injections. The cost/benefit ratio is not appealing.

Platelet concentrate and marrow stem cell injections have shown similar results as steroid injection. They have not shown any evidence of joint preservation or cartilage regeneration. They are expensive.

Prolotherapy is expensive, illogical and has no scientific merit.

Anti-rheumatoid Medications

More powerful anti-rheumatoid medicines such as steroids, gold (oral or injection), methotrexate, embrel, or others are often used by rheumatology specialists to treat inflammatory arthritis such as rheumatoid arthritis. They have excellent proven benefits for the right patient. They do not work for osteoarthritis.

Unproven Alternative Treatments

Chiropractic manipulation may be helpful in alleviating back symptoms that are often confused as “hip pain”, but there is no role for this in the treatment of hip arthritis.

There are many unproven alternative treatments such as magnets, wraps, devices and herbs, prolotherapy, that may act on the basis of a placebo effect.

Benefits of Hip Replacement

When all of the non-operative methods have been considered and are found to be undesirable, hip replacement may be indicated. There are several types of hip replacement that will be discussed later. It must be remembered that hip replacement does not give you a normal joint. It is an artificial joint. It is not as durable and long lasting as a normal joint and it is not as stable as a normal joint.

If a person with a normal joint has a hip replacement, he would not be happy. Similarly, a person with only mild arthritis would not feel a marked improvement with hip replacement. On the other hand, 95% of people with severe arthritis notice a dramatic improvement.

Total hip replacement is one of the most successful of all surgical procedures. A successful result is defined as freedom from pain and restoration of motion as well as function. A successful hip replacement will allow a person to return to the routine activities of daily living. Patients receiving hip replacements must follow some activity restrictions; with hip resurfacing unrestricted activity is allowed.

Risks and Complications of Hip Replacement

Click a heading below to learn more about different risks and complications that can happen with hip replacement and how Dr. Gross uses his expertise and experience to minimize each one.

Medical Complications

All surgeries have risks, so the potential benefits must be carefully weighed. Some complications are directly related to the surgical procedure and I call these surgical complications. Some are related to the stress we place on the body by the trauma of surgery, I call these medical complications.

Medical complications include but are not limited to: heart attack, stroke, kidney bladder dysfunction, and bowel dysfunction. I am unable to quantitate these for you. If you have significant underlying medical conditions, you should consult with your medical doctor or medical specialist (e.g. cardiologist) about your risk and how to best limit it. We recommend a complete physical by your personal physician and medical clearance in writing prior to surgery.

Medical clearance does not mean that your medical doctor or I can predict or prevent a major medical complication. It means that your doctor feels your medical condition has been optimized prior to surgery. I am a surgical specialist and not a medical specialist; therefore I need your personal physician to make this call. I want to avoid any surprises during or after the operation. For example it has been shown that people who have had a heart attack should ideally wait for 6 months to have elective surgery to minimize risk. Also people over 80 years age have a 25% risk of major medical complication with joint replacement surgery.


General and spinal anesthesia seem to be equally safe and effective for most people. The early recovery process is better with spinal anesthesia plus sedation; we therefore recommend it for most patients. We usually only use general anesthesia for the rare patients in whom spinal fails to work. However, the final choice is yours to make. Prior to the surgery, the anesthesiologist will discuss the options with you and help you to decide which type is best for you.



Using a comprehensive blood management program, my transfusion rate for hip replacement and resurfacing is less than 0.1%. If you have bilateral surgery the same week the transfusion rate is still less than 1%. For purposes of comparison, the national transfusion rate for hip replacement is 20-30 %.

If a blood transfusion is required, there is a potential risk for a transfusion reaction or disease transmission (e.g. hepatitis, AIDS). The risk of contracting AIDS from a blood transfusion is now estimated at one in a million. The risk of contracting hepatitis is approximately one in two thousand.

If your hemoglobin is low prior to surgery, you should take iron supplements and possibly a series of erythropoietin injections (Procrit) to build up your hemoglobin level. Using autologous blood is costly, inconvenient, and of questionable value. With my track record, it is unnecessary, however it can be arranged if you desire.

Our blood management protocol is as follows:

  • Measure preop Hg
  • If Hg < 15, start prescription iron
  • If Hg < 13, recheck Hg 1 month preop
  • If Hg < 13 again, administer procrit
  • Auquamantys tissue sealer used in surgery to limit bleeding
  • Minimally invasive surgery; average blood loss is less than 150ml. (Compare this to the literature 500-1000ml)
  • Platelet concentrate

Learn more about our Comprehensive Blood Management Program »



My rate of early postoperative (within 3 months) deep hip infection is 0.1%. These can usually be cured with aggressive treatment without loosing your implant as long as you keep me informed about problems. If you live out of state and let someone else manage your care, the result may not be as good. For comparison purposes, the national infection rate is 1-2%.

Higher risk patients are those with:

  • diabetes
  • other immune suppressive conditions
  • obesity
  • previous hip surgery

I believe our results are superior because we have developed a comprehensive program to prevent infections including the following:

  • Preop evaluation
    • No active infection
    • Medical clearance
    • Hg A1c< 7 (if diabetic)
    • normal prealbumin
  • Preop Hibiclens shower
  • Shave surgical site
  • Mupirocin into nostrils
  • IV antibiotics for 24º
  • Duraprep and plastic adhesive
  • Clean air OR + body exhaust suits
  • Efficient minimally invasive surgery
  • Intraarticular Vancomycin
  • Betadine jet lavage irrigation
  • Gentamicin loaded cement
  • Quill barbed suture closure
  • Dermabond (superglue) skin seal
  • Acticoat silver dressing (antibacterial) for 7 days
  • No dressing changes or wound checks
  • Daily mupirocin on incision after acticoat is removed.

Although only some of these measures have been individually proven to decrease infection, we think the combined use of all of them has driven our infection rate more than ten times below the national average.

Most infections in total hip replacements occur either due to contamination at thetime of surgery or from bacteria that invade from the skin through the incision before it is fully sealed within the first few weeks after the operation. It is a myth that surgery can be a truly sterile procedure. The wound also does not become completely sealed for at least one month after surgery. The program works because we address the problem of potential infection from multiple angles: optimize the patient, clean the skin, keep the OR contamination to a minimum, provide antiseptics and antibiotics to kill any residual bacteria, and prevent any bacterial access to the wound postoperatively.

We do not keep track of minor wound problems in a systematic way in our database. I estimate that they occur in less than 5% of patients. Bruising is normal. If you keep me informed about redness, drainage or any wound separation, these can usually be managed without resulting in deep infection.

In the rare case where deep infection occurs, these can usually be cured without loss of implants if treated aggressively with debridement and intraarticular antibiotics.

Late infections (after 3 months) are not directly related to the surgery. Lifetime risk is far less than 1%. Usually the implant has to be removed to cure these. For the rest of your life, cleaning all cuts with an antiseptic like betadine, treating any bodily infections promptly and taking a single dose of preventative antibiotics prior to any invasive procedures as well as prior to teeth cleaning are unproven, but prudent precautions.


Blood Clots

(0.2% DVT, 0 PE)

When we perform hip or knee replacement operations we create tissue trauma that naturally cause the body to respond with a clotting response. Patients who have a defective clotting system such as hemophilia would bleed to death with these operations if we did not artificially supplement their clotting system. I use careful surgical technique, electrocautery, the Aquamantyss tissue sealer and platelet concentrates with Thrombin to minimize perioperative bleeding. But this is not enough. We depend on the patient’s normally functioning clotting system to do the rest. Clotting in the wound is natural and absolutely necessary. But sometimes the patient’s clotting system over reacts and clots are formed in the veins of the legs and pelvis.

This can lead to problems. Especially when these clots break off and travel to the lungs (pulmonary embolus). Preventative measures include rapid mobilization of the patient, pneumatic compression devices (SCD) and use of drugs that impair the clotting mechanism commonly referred to as anticoagulants or “blood thinners”. Although these drugs can reduce the chance that abnormal clots form in the veins, they also reduce the desirable clotting that occurs in the wound itself. This leads to more bleeding for up to several days postoperative.

This may then lead to more pain as well as wound drainage. The more the wound drains, the higher the chance of infection. Rarely they can cause a stroke or subdural hematoma. Therefore anticoagulants have two effects: they decrease thromboembolic events (undesirable vein clots) but they increase the rate of infection. Every persons clotting system is different. But efforts to quantitate this so far have been ineffective. We are unable to predict how strongly an individual’s clotting system will respond. The best risk-benefit ratio therefore seems to some form of limited anticoagulation for most patients.

Without any preventative measure, the incidence blood clots in the legs or pelvis (deep venous thrombosis, DVT) is approximately 50% to 60% and the incidence of blood clots traveling to the lungs (pulmonary embolus, PE) is 10%. The risk is higher in patients who are obese or who have a know hypercoaguable state. In and of themselves DVTs are not a great threat; they can be treated with blood thinners and will ultimately resolve. The patient may, however, be left with some permanent swelling of the leg due to destruction of some of the valves in the veins. But PE carries a 1% chance of death.

The protocol that we are currently using has resulted in a < 1% chance of DVT and no PE in over 1000 patients.

  • Avoidance of entering marrow canal: resurfacing
  • SCD for 24º, beginning in the operating room
  • Spinal anesthesia
  • Rapid mobilization
  • Xarelto for 2 weeks/ 4weeks for high risk patients
    (once a day oral medication, no injections or blood monitoring needed)
  • ASA

Nerve Injury


The sciatic nerve is at risk in hip replacement. It can be cut accidentally, but typically it is stretched excessively during surgery causing numbness in the foot and a foot drop. If this does occur, the foot of the operated leg remains numb after the spinal anesthesia wears off and it is difficult to pull the toes towards the head. This can only occur immediately after the surgery (If you develop numbness or foot drop a week or month after surgery, it is probably being caused by a separate back problem). The deficit may be minor a transient or more complete.

There is no known treatment to make the nerve recover. Younger patients have a higher chance of nerve recovery. Nerves regrow at a rate of 1mm/ day. Therefore if recovery occurs, it may take up to 18 months. Early in the process there may be a burning pain that can be treated with nerve agents such as Lyrica. A brace (spring loaded sports ankle foot orthotic) can be prescribed to help prevent toe dragging. Usually partial recovery occurs. After 18 months, consideration can be given to a tendon transfer operation to return foot function.

The national rate of sciatic injury in THR is 1-2%. During my first 500 HRA I had a 1% rate of this problem. During the last 2500 case we have had none. In THA my rate is 0.1%.


(0.2 %)

This is the single biggest problem with hip replacements. This is when the ball comes completely out of the socket. A normal hip is held in place by ligaments as well as muscles around the hip. The normal femoral head is quite large and difficult to dislocate. It requires a fall from 2 stories or a blow of knee onto the dashboard of a car at 30 mph to do this. Usually a bone will break first.

Most total hip replacements (THR) have a smaller head than the normal hip. The smaller the artificial head, the higher the risk of dislocation. Also in THA a metal stem replaces the top of the femur. The stem imperfectly reproduces the natural anatomy of this bone. This is also a factor in instability. Also, during the operation, the major stabilizing hip ligaments (hip capsule) are cut. If the patient bends the hip too far, the hip may dislocate. It requires no significant force as with a normal hip.

The risk of dislocation is approximately 5% within the first year after surgery if a standard 28mm bearing is used. If a 36mm bearing is used, the risk is 1%, if anatomic sized metal bearings are used the risk is < 0.2%. When the risk of dislocation over 10 years is considered, it doubles. When a hip dislocates, you can’t walk and you need to go under anesthesia to have it manipulated back into place by your surgeon.

The Problem

About half of all people who dislocate a hip end up having repeated dislocations and require surgery to try to correct this. This is the most common cause for revision hip surgery in the US. It accounts for over 22% of all revisions. Patients with the following conditions are at higher risk: dysplasia, obese, neuromuscular conditions such as MS or Parkinson’s disease. The risk is somewhat influenced by the type of surgical approach (anterior vs. posterior) implant design features other than the head size (lateral offset, neck diameter) and implant position (primarily of the acetabular component). But bearing size is by far the most critical factor. Although surgeons often speak of ideal component positions, attempts to define a safe zone for implant positioning has so far been unsuccessful with these smaller bearings.

When larger bearing sizes are used with a plastic socket liner, the liner has to be made thinner. When this was tried 20 years ago, plastic wear increased dramatically causing extensive bone destruction (osteolysis). We had to abandon this idea and return to smaller bearings and accept a higher dislocation risk. Metal bearings became available 10-15 years ago. In the laboratory they produced very low wear rates even with larger bearing sizes. Because large metal bearings are obviously more stable, these became very popular a few years ago.

However we have learned that they do have a different set of problems. When implanted into people, large metal bearings sometimes produced higher wear rates than expected and this metal debris caused swelling, pain, and eventually soft tissue destruction that I have named an adverse wear failure (AWF). In addition, all larger bearings (including plastic and ceramic ones) may put excess stress on the stem trunion (where the head attaches to the neck of the metal stem) resulting in corrosion and also AWF.

Therefore the downside of more stable larger bearings is AWF produced by excess metallic debris. But we have found that this problem is related to specific implant design (brand) and acetabular component position. I will explain this in more detail in the section on AWF. In addition there may be very rare patients with allergy to metal, but we have no reliable test for this and the rate appears to be less than 0.025%.

The Solution

My solution to the problem is to use a proven well-designed metal bearing with precise positioning of the acetabular component. There is only one design that has been recalled for bearing wear problems, the DePuy ASR total hip and resurfacing system. For hip resurfacing I use either the Biomet or Wright system because their bearings are sound and they are the only companies to offer an uncemented femoral component (different discussion). For total hip systems we must not only consider the bearing design, but also the trunion design.

It is still not entirely clear what trunion design is optimal for large heads. But I am strongly suspicious that the Biomet design is superior for several reasons. Again, it appears that DePuy had serious flaws with their trunion and had the worst problems. Biomet has a completely different trunion than DePuy and most other companies. The stem is titanium and the neck adapter is titanium. The attachment of the neck adaptor to the cobalt-chrome head is at a massive trunion. One comparative study has shown that this unique design releases significantly lower amounts of metal ions than other trunion designs.

In addition, many companies added grooves to their stem trunions over the last 10 years to better accommodate ceramic heads. They also made them smaller to reduce the risk of impingement and dislocation. Biomet did not do this. I have not seen any trunion failures with the Biomet implants over 7 years of use. We are in the process of compiling a formal study with metal ion levels to assess this more carefully.

For hip resurfacing and large bearing THR, my risk of dislocation has historically been less than 0.2 % and AWF rate has been 1% at 10 years. Both of these are falling further now that we have finally discovered a “Safe Zone” for acetabular component positioning for large metal bearings. In a study of 761 cases we found that the dislocation rate and the AWF rate was ZERO if we placed the acetabular component within a certain range that we named RAIL (Relative acetabular inclination Limit).

In the last 2 years we have been able to place 100% of all implants within RAIL. I believe the risk of dislocation and AWF is now negligible for HSR and THR. For rare patients who cannot tolerate cobalt chrome, I think the best solution is a 36mm Biolox ceramic head on a Biomet titanium stem against vitamin E doped cross-linked polyethelene. I only rarely use this implant and can therefore not give you my personal stats. But this carries a 1% theoretical risk of dislocation, and probably little risk of trunion corrosion. The plastic liner is thin and therefore carries some as of yet unknown risk of breakage by 10 years. Impact activities should be avoided.

To prevent dislocation, patients with THR using smaller bearings need to follow lifelong restrictions. They should never bend their hip into extreme positions as required in ballet, palates, yoga and kayaking and squats. The risk is less with a 36mm bearing than the standard 28mm bearing. Patients with large metal bearings with HRA or THA have to limit extreme positions for 6 months until the hip capsule has healed, them they no longer have position restrictions.

Leg Length Inequality

Lengthening up to 5mm is typical as lost cartilage is replaced. Patients will accommodate to lengthening up to 1 cm by pelvic tilt within 6 months after surgery. Lengthening greater than this is only rarely possible in certain cases of deformity.

Significant leg lengthening is defined as increasing the length of the leg more than 1 cm (3/8 inch) in surgery. This occurs in about 5% of stemmed THR. Most patients accommodate well to such minor changes in length. 1 cm is only 1% of the length of the leg. The pelvis is designed to shift and tilt over 2 cm from side to side to make up for minor leg length differences. No person is born with exactly equal leg lengths. In a study of healthy military recruits it was found that 25% have a difference of over 1cm from side to side.

There is no scientific evidence that a difference in leg lengths causes problems in other joints including in the back. Nevertheless chiropractors and physical therapist are prone to diagnose misalignment and prescribe lifts. There is no scientific basis for this. Just as there was no scientific basis for all the braces orthopedic surgeons historically used to prescribe kids with various deformities. It kind of made sense so it was done- but it has been largely abandoned by our profession because evidence of its ineffectiveness has accumulated.

Occasionally the length of a leg is inadvertently lengthened during standard stemmed total hip replacement surgery, especially in a patient with loose ligaments. Often the surgeon plans to slightly (<1cm) lengthen the leg to increase tissue tension and thereby reduce the chance of dislocation in a small bearing total hip replacement. If length is increased by more than 2 cm beyond the opposite leg, patients will often not accommodate to it with time and find it unpleasant. But it will not hurt other joints. The solution is to wear a 1cm (3/8) lift inside the opposite shoe. This does not affect appearance; other people cannot notice this. If more than 1 cm lengthening is required, the buildup is first put on the shoe, and then additional amount is placed on the sole if necessary.

With hip resurfacing it is only rarely possible to increase the leg length even if the surgeon tries to do it. This is because we are only cutting away a small layer of bone and replacing it with metal on both sides of the joint. Usually the leg is lengthened 0-0.5cm because lost cartilage is replaced. In certain cases of bone deformity length may be increased slightly more as the deformity is corrected. In patients who have a major leg length discrepancy, this cannot be corrected with resurfacing, but may be correctable with a stemmed total hip replacement. The patient must then decide what is more important to them, gaining up to 2 cm in length (THR), or preserving the top of the femur (HRA). We are unable to shorten the leg with either operation, because hip instability may develop.

Before surgery, with an arthritic hip most people have slight shortening due to loss of cartilage or bone. It is not uncommon for people to feel major shortening or even lengthening has occurred because of the arthritis. This sensation can be caused by pelvic tit associated with an arthritic hip. Sometimes this tilt is toward the hip and sometimes it is away. True change in length can be measured on the x-ray. On the other hand, measuring a patient’s leg length lying or standing is completely unreliable. After surgery, for up to 6 months, pelvic tilt as a response to the trauma of surgery can also occur. This can give the patient a false sense that major length change has occurred. The x-ray will again help the patient understand that this has not occurred. This sensation usually resolves by 6 months after surgery.

Heterotopic Bone

Abnormal bone may form in the tissues adjacent to the joint as a reaction to surgery. Some patients are more prone to this. This does not cause pain. If it is extensive, it may decrease motion. Most patients with an arthritic hip have loss of motion. After resurfacing the hip returns to near normal motion after 1 year of healing. Exceptions are case with certain deformities, extreme stiffness before surgery, and in rare cases where extensive heterotopic bone forms.

We try to prevent this by the following measures:

  • Protective covers over muscle during surgery when bone is reamed.
  • Thorough jet lavage of hip prior to closing.
  • 2 week course of celebrex or Mobic
  • Single doe of x-ray therapy after surgery in high risk patients.

Fractures in Surgery

Occasionally cracks are seen when implants are driven into bone. This is because bone is prepared for a very tight initial fit of the implant.

In hip resurfacing the femoral side never fractures in surgery. It is extremely rare to see a socket wall fracture. These are typically stable and require only that the patient stay on crutches longer after surgery.

In stemmed total hip replacement, 1-2 % of cases suffer a crack around the top of the femur during stem insertion. This can easily be handled with a cable placed in surgery around the crack. These patients usually also need to stay on crutches a little longer after surgery.

Fractures after Surgery

(0.1% HRA, 0.7% THR)

In Hip resurfacing, the femoral neck may fracture during the first 6 months of healing. I have never seen it occur thereafter, even with significant falls. The femoral head can gradually collapse within the first year. Both of these problems combined are called early femoral failure. When I first started doing resurfacing my rate was about 2.5%. We have extensively studied this problem and found a solution. These fractures are related to weak bone and excessive patient weight. We now always measure bone density before surgery with a DEXA scan.

Patients with weak bone or BMI >30 are paced on crutches longer and/or are prescribed a bone strengthening medicine for 6 months. Using this protocol, we have reduced the early femoral failure rate to 0.1% in the last 1000 cases. These fractures can occur gradually as a stress fracture due to early over activity, or from a minor fall during the first 6 months after surgery. If this occurs, we need to revise the femoral side to a stemmed THR.

Femoral trochanteric and shaft fractures occur after stemmed THR. The reported rate is 0.7% in one major study. At this moment I cannot quote my personal rate because we are still compiling the data. Trochanteric fractures are repaired with a clamp, while shaft fractures usually require revision to a longer stem plus cables. We have not studied bone-strengthening agents in THR patients.

Failure of Bone Ingrowth into Implants

(Acetabular 0.2%, Femoral 0/2000 HRA, 0/1000 THR)

Implants need to be firmly attached to bone to function correctly. If they are loose, they rub on the bone causing pain. There are two methods to fix implants to bone: cementing and bone ingrowth. The advantage of cement is immediate fixation, while the disadvantage is lower durability. I strongly favor bone ingrowth implants. The disadvantage they have is a low rate of bone ingrowth failure. Most US surgeons favor bone ingrowth in THA except possibly in very old weak bone, where cement may still have an advantage.

Approximately 90% of all THR implants are bone ingrowth types. The socket component that I use for HRA and THR are the same. We had some problems with bone ingrowth failures in dysplasia case with severely deformed anatomy before 2007. However, since then the introduction of a component with supplemental fixation (Trispike Magnum) that we can use in these deformed cases, has allowed us to decrease the rate of acetabular bone ingrowth failure to 0.2%. We have not had any failure of bone ingrowth into the uncemented femoral component in HRA or THR in 5 years.

Implant Loosening

(3% @ 10 years for cemented HRA femoral component)

Sometimes implants are initially well fixed to bone, but this bond can break down over time. His process is called loosening. Loose implants rub on bone and hurt. Uncemented implants are initially fixed to bone by a tight press-fit. But they are not truly considered fixed until bone ingrowth occurs. It can be difficult to know for certain if this process has occurred until you see a patient 2 years after surgery and they are without pain and have a stable x-ray. After that, if an implant becomes unstable w.r.t the bone it is thought to have loosened. This is extremely rare. It could possibly be caused by inflammation from excess wear debris (either plastic of metal).

In the Corin Cormet 2000 HRA we have seen 5/373 (1.3%) cases where the porous coating debonded from the uncemented acetabular implant causing loosening after 7 years of implantation. We have not yet seen this in the Biomet Magnum acetabular component, which we started using 7 years ago.

With cemented femoral components of HRA we have seen a 3% rate of loosening @ 10 years. We believe that this will not occur with the uncemented components. We started implanting these in 2007. It is still too early for us to see any difference statistically in the overall patient groups. However, in a small high-risk group of patients with osteonecrosis of the femoral head we have seen better results already.

Implant Breakage

We have never seen this in HRA, except one broken femoral stem in an implant that is still functioning many years after we saw this on x-ray. The implant is fixed to the bone by cement under the bearing; the stem did not provide any fixation.

Implant breakage was a known cause of failure when THR stems were made of stainless steel. It is rarely seen with cobalt chrome stems. It is exceedingly rare with the titanium stems that I have been using for years. I have never personally seen one fracture. But if young athletic patients run on these for years, it is possible that this may become a late failure mode. Extracting a broken stem is quite difficult. Therefore I recommend no running more than 1-2 miles at a time with a stemmed THR.

Wear Related Failure

(AWR in HRA 1% @ 10 years)

All artificial implants wear and release debris into your body. If the level of debris generation is low, the body can tolerate it well for many years. There are many different bearing surface options. In HRA only cobalt-chrome metal on metal bearings work. There is only one bearing surface and no additional junctions that can wear or corrode.

With stemmed THR there are four bearing options:

  • Metal on plastic (polyethelene)
  • Ceramic on plastic
  • Ceramic on ceramic
  • Metal on metal
  • Metal on ceramic

The most commonly used are listed first. In addition to the bearing, wear and corrosion can occur at numerous implant junctions in stemmed THR. These include: liner on socket, ball on stem trunion, and modular junctions.

In the past, plastic (polyethelene) wear was a major problem particularly in younger more active patients. Once produced, plastic debris has no way to exit the body. It accumulates around the implant and travels along the lymph channels but it never leaves the body. These bearings carried a 30% failure rate by 8 years in patients under age 50. If a large amount of plastic debris accumulates around the hip, the body’s immune system reacts against it and destroys bone. The result is often extensive bone destruction, which is called osteolysis. There is no way to measure the amount of plastic particles released into the body. Improvements in plastics (cross-linked polyethelene) appear to have solved this problem. The plastic wear rate has been reduced dramatically. But the down side is that these plastics are more brittle, increasing the risk of implant (liner) breakage with impact activity. As the new plastic liners have become more wear tolerant, we have moved into larger bearing sizes to improve stability. In this situation, the liner becomes thinner and breakage becomes a greater concern. These are not suitable for impact activity.

Ceramic on ceramic bearings produce the most benign debris. Cases of adverse reaction to ceramic debris are exceedingly rare. If an implant was chosen based primarily on debris generation, ceramic on ceramic would be the clear favorite. The amount of ceramic debris deposited in the body cannot be measured. Unfortunately these cannot be used for resurfacing. Ceramic fracture is also an exceedingly rare event with current ceramic bearings. But as ceramic bearings are made larger to improve stability, the liner becomes thinner and fracture may become a problem, especially with impact activity. The main problem currently is that larger bearing sizes are not available, making instability a persistent problem.

Metal on metal bearings are unique because very thin one-piece acetabular components can be manufactured in which there is a porous bone ingrowth surface on the outside, and a polished bearing surface on the inside. This allows us to reconstruct the hip of each individual patient with its natural bearing size, providing normal hip stability. This also allows us to preserve the femoral head for resurfacing. Alternatively, a large metal head can be placed into this acetabular component and attached to any standard total hip stem. This results in a very stable hip joint. All metal on metal bearings are made of cobalt chrome. The wear products are cobalt, chromium and traces of nickel and molybdenum, which are also present in the alloys used. In a well functioning metal on metal bearing the amount of wear debris generated is very small and is well tolerated by the body. It is deposited in the tissues around the hip. It is then absorbed into the bloodstream and excreted in the urine. A level can be measured in the blood or urine. I have used over 4000 metal bearings; the vast majority are well tolerated by the body.

If a well-designed metal bearing is implanted in the correct orientation, the wear rate is low and the small amount of wear debris is well tolerated. Numerous large long term studies have been done showing that these particles do not cause cancer. There are a handful of individual case reports of systemic metal toxicity. Most have these have not been in cases of metal bearings. None of the cases that I have treated for adverse wear reaction (AWR) have had any signs of systemic toxicity, despite extremely high metal ion levels being measured.

There is no evidence that the metal ions released form bearing wear cause cancer or kidney damage, and even systemic reactions are rare in cases of excessive bearing wear.

Adverse Wear Reaction (AWR)

Local inflammatory tissue reaction to excess metal wear debris is the problem. I have called this an adverse wear reaction (AWR). In plastic bearings, excess debris tends to cause more bone destruction and less soft tissue inflammation, in metal bearings there tends to be more soft tissue inflammation and less bone destruction. In cases of AWR to metal debris there is fluid collection, metallic staining of tissues, and production of inflammatory masses (not cancer). If severe reactions are not treated for years, muscle destruction can occur. But I have not yet seen any case of muscle damage.

We now recommend measuring blood metal ion levels on all patients at 2 years after surgery to assess their wear rate. We have found that this is an extremely helpful test to discover patients whose wear rate is excessive. Using blood ion level testing, we have found some patients who have an early AWR that is not yet symptomatic and I have revised them. On the other hand, we have found a few cases with high ion levels without AWR and we are monitoring them with yearly levels.

We have done extensive studies on AWR. Based on detailed studies of hundreds of patients with accurate x-rays and ion levels, we have been able to develop a “safe zone” for placing acetabular components to prevent AWR. This paper will be published in Journal of arthroplasty in 2013. This safe zone is based on bearing size. Although safe zones have been published previously for plastic bearings (to prevent dislocations), they are very unreliable. Our safe zone reliably prevents both AWR and dislocation with >99% accuracy. This has never before been achieved for any type of hip replacement type.

The cause of the AWR in metal bearings is now fairly well understood by most hip resurfacing experts. I will try to summarize the problem briefly. AWR occurs when a metal bearing exhibits an abnormal wear pattern called edge loading. When this occurs, the natural fluid lubrication film breaks down and an extremely high wear rate ensues. A large amount of metal is produced and deposited in the surrounding tissue leading to the AWR. Elevated metal levels will be measured in the blood. There are 2 factors that will result in edge loading; an acetabular component that is shallow by design, or a component that is placed in too steep of a position (High inclination angle as measured on a standing pelvis x-ray).

The recalled Depuy ASR implant had an excessively shallow design, this is one reason it had a 30% failure rate within 5 years. It is a quirk in design that in virtually every resurfacing system on the market, the smaller bearing sizes have shallower acetabular components than the larger sizes for the same brand. This is the primary reason why smaller bearing sizes carry a higher risk of AWR than larger bearing sizes in every system. Women tend to have smaller bones and typically require the smaller sizes; therefore they have higher rates of AWR. AWR occurs when an acetabular component is implanted too steeply. The more steep the acetabular inclination angle (AIA), the less well the head is “captured” and the more likely that edge loading and AWR will develop.

In our studies, no components with AIA< 50º on standing pelvis x-ray have developed AWR, while about 5% of those with AIA>50º have had this problem. We have also had no cases of AWR in bearing sizes >48mm. But the AWR can be avoided in smaller sizes, simply by implanting them with lower inclination angles. This allows the shallower component to function well without edge loading. Our paper on safe zones makes this very clear.

In addition to the fiasco with the Depuy ASR (total hip and resurfacing) recalled in 2010, there was a very disturbing report published by the Oxford Group in the JBJS British Journal in 2008. This was the first major clinical series highlighting the problem of AWR. This group found a 4% @ 8 years rate of AWR in a series of 1400 cases while using proven well designed implants. They called these failures “pseudotumors” and speculated that they may be severe allergic reactions to metal. Most disturbingly, they reported that these failures were not related to steeply implanted acetabular components. We have now published a larger report of 2600 cases with a 1% rate of AWR in 10 years in the journal hip international 2013. Our data clearly indicate that AWR is caused by steep component placement, particularly in smaller implant sizes. All 8 of our cases had AIA>50º and bearing size

To make matters worse, the Oxford Group soon published a report on the results of their revision surgery for “pseudotumors”. It showed disastrous outcomes for these patients. I have not yet published my outcomes for revisions of AWR (my own 8 cases plus others referred to me from elsewhere), but can assure you that my results again are diametrically opposed to their report. I have not even transfused any of my cases. The revision surgery for AWR is actually quite straightforward and carries only a slightly higher risk than the original operation.

The combination of the DePuy ASR disaster and the poor results with good implants from the Oxford Group, have scared many surgeons away from large metal bearings for stemmed THR and resurfacing. This is a shame, because we now know that the problem is virtually completely avoidable with proper implant choice and placement. These large metal bearings are the only ones that provide a truly stable hip joint and avoid the most common problem in hip replacement: recurrent dislocation.

Metal Ion Testing

We have made a concerted effort to obtain metal ion testing on all of our patients who are at least 2 years postoperative. It is important to recognize that metal ions found in the blood are not in and of themselves a problem. We use blood ion levels in two ways. First, they are used a screening test to see if AWR are developing in asymptomatic patients. We have found occasional cases where this is true. Secondly, in patients who are having pain, a low ion level is very good evidence to rule out an AWR. If a metal ion level is high we then perform either a metal suppression CT or MRI scan to see if a substantial fluid collection or soft tissue mass (not cancer) is present.

Small amounts of fluid can be normal around well-functioning implants (A hip replacement or resurfacing is not a normal hip). A large collection together with a high ion level is diagnostic of AWR. This is then confirmed at the time of revision surgery with extensive metal staining of the tissues. If the metal level is high but there is no fluid collection we recommend yearly monitoring with ion levels. We are not certain what the long-term outcome will be in these cases, but we don’t think it is dangerous to observe these patients. Sometimes metal levels can be elevated when an implant is loose (this is symptomatic).

There are no accepted guidelines regarding what constitutes an acceptable ion level. We have extensive experience and have developed our own internal guidelines. We consider any level below 10ug/L safe and would only recommend further testing in a significantly symptomatic patient. Patients who have bilateral implants or even joint implants elsewhere in the body may have higher levels, as could patients with kidney dysfunction, or those who are taking vitamins or supplements (they may contain chromium even without listing them).

Normal levels as reported by the labs (for patients without implants) are below 2ug/L. As we are getting better at placing these components, we are seeing a trend of more patients with very low levels, even many in the normal range. There is a period of “run in wear” with these bearings that lasts 1-2 years. Ion levels are somewhat higher during this time. This is why we have chosen 2 years as our starting point for testing. Long-term studies have shown that there is a general trend of ever declining levels out to 10 years.

One study has shown that ion levels for total knee replacement are similar as for a well-functioning metal on metal hip replacement. Knee replacements have a cobalt chrome femoral component that articulates on a plastic liner; they are not metal on metal bearings. About 300,000 of these are done annually in the US. There is no evidence that mildly elevated metal ion levels have caused any clinical problem in TKR over the last 2 decades. This is further evidence that mildly elevated metal ion levels are not harmful.

In conclusion, ion levels will be elevated in HRA, but there is no evidence that this harms the body. Measuring ion levels is primarily useful in diagnosing local (around the hip) adverse wear reactions (AWF).

Types of Hip Replacement

Total hip replacement is an operation designed to replace the damaged joint. All types of hip replacement are based on the principal that a section of bone must be removed off of the end of each bone (femoral head and acetabulum) and replaced by an artificial piece that is well fixed to the bone on both sides of the joint.

Implants fixed solidly to both bones rub against each other when the hip moves, preventing the bone ends from being irritated. Many types of total hip replacements are currently utilized and can be classified in several different ways.

There are many brands available of each category and there are hundreds of factors (e.g., type of metal, shape of implant, sterilization method, tools for insertion, etc.) that must be considered when choosing the appropriate implant in each case.

Click on a heading below to learn more about each one.

Types of Fixation To Bone

Cement Fixation

In 1962, Sir John Charnley used a small (22mm) stainless steel ball on a long stem which was inserted into the bone to replace the femoral (ball) side of the joint and a high density plastic socket to replace the acetabular (socket) side. Both of these components were secured to bone with a self-curing acrylic polymer commonly referred to as bone cement (methyl methacrylate).

Several generations of designs have evolved from this original Charnley prosthesis. The ball is now modular thereby allowing balls of different sizes, materials, and neck lengths to be placed onto the stem. Most balls are now made of either a cobalt chrome metal alloy or a ceramic material. Stems are now made of either cobalt chrome or titanium. The socket component is usually titanium with a bone ingrowth porous surface and an exchangeable bearing liner. The liner can be made of polyethelene (plastic), cobalt-chrome (metal), or ceramic. Sockets fixed with cement have largely been abandoned in the US. Cement fixation of the stem is now used in less than 10% of hip replacements, usually in older weaker bone.

Bone Ingrowth Fixation

We are now in an era with widespread use of devices that are designed to attach to bone without the use of cement. Bone will attach to a metal implant if the surface of the metal has a rough or porous surface. This process is called bone ingrowth or osseointegration. The bone must be prepared precisely for these devices. For successful bone ingrowth to occur the implant must achieve an initial stable press-fit when implanted and the porous coating must sit right up against live bone. In general, these devices are larger, longer, and stiffer than those used with cement but are proportional to the size of the individual bone. Surface coatings, such as hydroxyapatite, are also being utilized in an effort to hasten and/or enhance bone fixation. Many different devices using cementless fixation have been utilized since their introduction in the U.S. in 1977. It is now generally accepted that these implants remain fixed to bone longer than cemented devices. The theoretical downside is occasional failure of bone ingrowth, but this is a very rare problem, except possibly for very old weak bone. There is one other problem with these implants. In 2-5% of patients activity related thigh pain may develop. Even with well-fixed implants, there can be pain due to the stiffer modulus of these implants. There is no solution to this problem.

Hybrid Fixation

Hybrid fixation is when one component is inserted without cement, usually the socket, and one component is inserted with cement, usually the stem.

Bearing Surfaces

All artificial bearings create wear debris, just as the rubber wears off your tire going down the road. This wear debris is deposited in your body. If the load is small, you can usually tolerate it well for many years. Our goal is to use implants that generate the least quantity of wear debris as well as the type of debris that results in the least tissue reaction. The original Charnley bearing was stainless steel ball against plastic (polyethelene). This is no longer used. Modern alternative bearings have about 100X lower wear rates than the older cobalt chrome against standard polyethelene bearing.

Metal on Plastic

Metal on plastic are the most commonly used combinations. Plastic wear debris is deposited around the hip joint and may travel along lymph channels. But it does not leave the body. In young active people with standard plastic (polyethelene, SPE) liners, enough plastic debris is released to cause severe bone destruction in 30% of patients within 8 years of implantation. Newer cross-linked liners polyethelene (XLPE) have dramatically lowered this problem in small early studies out to 10 years. When ceramic balls are used against the plastic, wear debris seems to be further reduced.

Smaller bearing diameters produce less wear but result in higher risk of dislocation. Larger bearings were not possible with SPE for this reason. Because XLPE has better wear properties, larger heads are now being used. Although XLPE wears better, it is often more brittle. As the bearing size increases, the liner thickness decreases. More brittle XLPE may therefore be more subject to breakage rather than wear. Also, larger heads have recently been associated with trunion (where the head is attached to the stem) corrosion. Therefore, there is much disagreement about ideal bearing size because of competing problems: wear/breakage vs. instability.

Ceramic on Plastic

Ceramic on plastic has similar characteristics as above but probably cuts the wear rate in half.

For the standard 28mm bearing size dislocation risk is about 5% within 1 year, while it drops to 1% for 36mm bearings. By 10 years follow-up dislocation risk nearly doubles. About half of dislocations are recurrent and require revision surgery. The most common reason for revision hip surgery is instability.

Ceramic on Ceramic

Ceramic on ceramic bearing produces the least quantity and best tolerated wear debris of all bearings. Ceramic surfaces are brittle and can fracture, especially with impact activity. This is now exceedingly rare (less than 1:10,000). When these implants are placed in nonideal positions, they may exhibit a stipe wear pattern and emitting a loud squeak that can be head across the room. This can be very unpleasant and require revision surgery. This occurs in 1-2 % of cases, but can probably be resolved by better implant positioning and larger ceramic bearings.

The main problem with ceramic bearings is their size. The same instability problems exist with the standard 28mm bearing size. Larger sizes are now in use with a new stronger ceramic called Biolox. This will reduce the dislocation rate, but will require thinner ceramic socket liners. Time will tell if these will be equally fracture resistant as the thicker alumina ceramic liner that have 10 year data.

Metal on Metal

Metal on metal bearings made of cobalt chrome were first used in the U.S. when joint replacement began in the late 1960s. The component design and fixation techniques were primitive by today's standards. Further, the bearing manufacture was inconsistent and these devices were discontinued in the 1970s. Now with modern technology, bearing surfaces can be made optimally smooth and round and thus the wear is minimized.

We have learned that for optimal function, there needs to be less than 5 um residual roughness and a polar bearing arrangement with a 50-100um radial clearance. Cobalt chrome is the only metal that works. Trace amounts of molybdenum and Nickel are present in this alloy. There is still controversy about ideal metallurgy (cast vs. forged, high vs. low carbon content, heat treated or not) but the most commonly used is cast, high carbon non-heat-treated. M/M devices were reintroduced in Europe in 1988. There are now U.S. manufacturers as well as European firms manufacturing all-metal bearings. The reaction of our body against excess metal debris results in more soft tissue inflammation while plastic causes more bone destruction (osteolysis).

Metal bearings are so strong that very thin (4mm) socket components can safely be built without any risk of fracture. Also a bone ingrowth layer can be directly attached to this implant. Thin, strong, one-piece sockets allow reconstructing the hip joint with a natural bearing size, virtually eliminating hip instability, the most common complication of this surgery. In combination with similar thin femoral components, hip resurfacing is made possible.

Despite laboratory studies showing minimal wear, high wear states resulting in metalosis (excess metal in the tissues) have now been reported in patients. The incidence of this adverse wear failure (AWF) problem varies; in my experience it has been a cause of failure in 1% of cases at 10 years. In my experience, revision for AWF is no more difficult than revision for other failure modes. We have now learned the proper acetabular component positions to completely avoid this problem. It turns out that the problem is caused primarily by two factors, socket components that are designed very shallow as well as steep socket component inclination position. The combination of these problems results in edge wear releasing excess metal debris. (discussed more elsewhere)

Ceramic on Metal

Ceramic on metal has shown slightly lower metal wear in laboratory studies, but this has not been confirmed in the clinical studies.

How Much Bone/Joint is Replaced

Stemmed Total Hip Replacement

Stemmed total hip replacement is by far the most commonly used. John Charnley was the first to make this a routinely successful operation in the 1960’s. Numerous modifications have occurred since his time. Several millimeters of bone is removed from inside the socket and a metal implant with a porous ingrowth surface is tightly implanted into the prepared bone bed. A bearing liner is then locked into place in the implanted metal shell. This leaves a much smaller cavity for the ball.

Therefore the head and neck of the femur must be amputated. A stem is then fixed into the hollowed marrow canal of the top of the femoral shaft using either cement or bone ingrowth technique. A smaller (than natural) ball is then attached to the trunion of the stem (morse cone taper junction). This ball fits into the smaller socket liner.

Hip Surface Replacement

Hip surface replacement accomplishes the same basic goal as sTHR with much less bone removal and preservation of normal biomechanics. Bearing size and femoral offsets remain the same as for the normal femur. This was tried in the 1950’s by Charnley with Teflon implants, by others with primitive metal on metal bearings, and in the 70’s with metal on plastic bearings. Finally Derek McMinn applied modern metal on metal bearings to resurfacing in the 1990’s. Mainly because the femoral head is preserved, it is much more difficult for the surgeon to get adequate access to accurately place the deeper socket component.

In stemmed THR, the head and neck are amputated early in the operation allowing much easier access to the deeply placed socket. This technical difficulty the primary reason why many hip surgeons are reluctant to perform this operation. It has been demonstrated in numerous scientific papers that the complication rate is much higher when surgeons are learning this operation. This learning curve extends for several hundred cases. Difficulty in placing the socket component accurately is one of the major contributing factors to recent problems with adverse wear failure.

Hemi-Surface Replacement for Osteonecrosis

One option to minimize wear debris and tissue reaction is to eliminate the artificial bearing by replacing only the diseased part of the joint. A hemi-surface replacement was sometimes recommended in the past for patients who had osteonecrosis of the femoral head (also referred to as avascular necrosis) and had intact remaining articular cartilage on the acetabulum or pelvic side.

The hemi-surface replacement preserves and maintains bone by providing physiological stress transfer to the femoral neck and proximal femur. It avoids inflammatory reaction and loosening due to any artificial bearing wear debris. However, if only one half of the joint is replaced, the degree of pain relief is not as good as if both sides of the joint are replaced. It is not always possible to convert this to a total hip resurfacing. I do not advise the use of this operation.

Alternatives to Hip Replacement

Hip replacement is by far the best solution for severe arthritis (loss of articular cartilage) of the hip. However in some situations there is significant hip pain when the articular (surface) cartilage is still mostly intact. Patients who have hip impingement, hip dysplasia or osteonecrosis in the early stages of these conditions may be better served with other surgical options. Symptoms can often be significantly improved and the joint may be preserved for many years.

Click the headings below to learn more about the different alternatives to total hip repalcement.

Arthroscopic Hip Surgery

Arthroscopic hip surgery may be indicated for impingement syndromes, labral tears and loose bodies. Many orthopedic surgeons commonly perform arthroscopic knee and shoulder surgery. But arthroscopic hip surgery is more complicated and has been mastered by only a small number of surgeons. If you are considering this option, be sure to consult a surgeon who has experience with several hundreds of these operations.

The most common problem with hip arthroscopy is removing a torn labrum without addressing the underlying impingement deformity. This may provide temporary relief, but is not long lasting. Another error is when impingement surgery is performed when too much articular cartilage damage has already occurred. These mistakes are frequently made by inexperienced surgeons. When impingement surgery is performed on patients with minimal articular cartilage loss, more than 80% of patients have improvement in their symptoms.

The hope is that the hip joint will be preserved by this intervention, but this has no yet been proven. The ideal patient for impingement surgery is under 40 years with minimal arthritic changes on their hip x-ray. In these cases it is advisable to perform impingement surgery rather than hip replacement.

Arthroscopic Hip surgeons that I recommend are:

  • Allston Stubbs – Winston Salem, NC
  • Thomas Byrd – Nashville, TN
  • Marc Phillipon – Vail, CO

Impingement surgery can also be performed through mini open anterior approaches or through more extensive approaches. It has not been proven.

Ganz Periacetabular Osteotomy

Ganz Periacetabular osteotomy is most useful for patients with hip dysplasia. Procedures that realign the position of the acetabulum (socket) are called osteotomies. Many different types have been promoted in the past for young patients with hip dysplasia. 90% of dysplasia cases occur in young women. These women typically were born with mild hip deformities that do not cause problems when they are children.

The elements of the dysplasia deformity are: oval shallow socket, steeply oriented socket, flattened oval head, narrow, valgus and anteverted neck, hypertrophied labrum. Typically these women have extremely loose ligaments and have much higher than normal hip mobility. They gravitate towards gymnastics and ballet because of their extreme flexibility. They start exhibiting mild hip symptoms in their 20s and 30s.

The hips start to fail early for two reasons: incongruency and instability. A normal hip is a spinning sphere. When an oval dysplastic hip rotates, abnormal forces are experienced by the articular cartilage leading to deterioration. A shallow dysplastic hip is poorly contained. If the orientation is more vertical, the situation is worse. The labrum hypertrophies in an attempt to better contain the head.

The result is a hip that is highly mobile. But the labrum eventually gets overloaded and fails. The first symptoms usually appear in the 20s and 30s depending on severity of the deformity and possibly activity level. At this point the articular cartilage may still be relatively normal.

If their socket orientation is too steep, a Ganz periacetabular osteotomy can improve symptoms by reorienting the entire socket and thereby better containing the head. If socket orientation is acceptable, sometimes the early symptoms are coming from a tear of the hypertrophied labrum that can be repaired arthroscopically. Removing torn labrum in dysplasia is not advisable because this destabilizes the head and may speed up the hip degeneration.

Studies on acetabular osteotomies have shown over 90% success in symptom relief if there is only minor articular cartilage damage at the time of surgery. The hope is that the hip joint will be preserved by this intervention, but this has not yet been proven. The ideal patient for osteotomy surgery is under 40 years with minimal arthritic changes on their hip x-ray. The problem is that there is no way of completely correcting the deformity. There is no way to deepen the socket or make the bearing spherical without destroying the cartilage. A hip resurfacing does accomplish these goals, but this requires an artificial implant.

Experts in Ganz osteotomy that I can recommend are:

  • Michael Millis – Boston MA
  • Robert Trousdale – Rochester MN

Free Vascularized Fibular Graft

Free vascularized fibular graft is an operation that can reestablish blood flow to the femoral head. In osteonecrosis (aka avascular necrosis or AVN) the blood flow to the femoral head is impaired. The bone dies. Sometimes blood flow is reestablished and it heals spontaneously. If blood flow remains cut off, the dead bone eventually dies and the head collapses. This is stage 3 osteonecrosis. At this point hip replacement is the only effective treatment.

The femoral head is by far the most common bone in the body to develop osteonecrosis. It is most often caused by excess alcohol consumption, prolonged high dose steroid use (prednisone type, not muscle building steroids), major hip trauma (fracture or dislocation, not a hard fall on the hip) or sickle cell disease. Exactly why these cause necrosis is not known. Clearly, there is some individual susceptibility because only a small percentage of patients exposed to alcohol and steroids get osteonecrosis. About 1/3 of cases do not have any associated risk factors and are labeled “idiopathic”.

In the earlier stages, before collapse, there are often mild symptoms. There are several operations that have been promoted to induce new blood flow to the femoral head in order to heal it before it collapses. The only one that I believe is effective is the free vascularized fibular graft. It is a complicated operation that only a few surgeons routinely perform.

The fibula is a small bone in the leg that is removed together with its blood supply. The bone is inserted through a large hole drilled through the femoral neck into the femoral head. The blood vessels are re-connected to new vessels near the hip. New blood flow is now brought directly in contact with the dead bone in the femoral head. When this operation is done prior to head collapse, the dead bone can heal and the hip joint is preserved in 95% of cases. If the head is already collapsed there is no point to this operation because the joint cartilage has already lost its support and will always fail.

The problems with this operation are complexity, long recovery, and donor site morbidity. This is a long and complicated operation that requires multiple surgeons and is very expensive. Patients are usually required to stay on crutches for months after the operation. It is relatively safe to remove a 3-4 inch section of fibula from just above the ankle, because the larger tibia can take the load. But some residual leg or ankle pain may be present permanently. Also clawing of the toes may result as a complication of removing the fibula. In stage 1 and 2 of necrosis in a young patient I think it is worthwhile to consider this option.

I recommend Duke University Orthopedics – who have the most experience with this operation.

Core Decompression

Core decompression is a simple operation where drill holes are placed through the neck into the head of the femur. The hope is that new blood vessels will grow through these drill holes to re-vascularize the dead portions of the head. Many contradictory studies have been published. I am not convinced that there is any value to this operation and I do not perform it. Other surgeons still routinely offer this operation. There is some hope that injecting new bone growth stimulators (such as infuse) through the drill holes might improve the results. I have tried this in 10 patients, but I abandoned it after 5 failed within 1 year requiring hip replacement. I continue to hope that others will discover a technique to make this work.

Resection Arthroplasty of the Hip

Resection arthroplasty of the hip is a salvage operation for failed hip replacements that for some reason cannot be revised. It was developed by a man by the name of Girdlestone and is frequently referred to as the “Girdlestone Procedure”. It was originally used over 50 years ago as an operation to treat severe arthritis of the hip by removing the entire ball portion of the upper end of the femur.

This essentially removes the hip joint and allows the femur to shorten. Scar tissue develops between the upper end of the femur and the pelvis bone and allows motion with minimal pain. The leg, however, is quite short and weak and usually patients require at least a cane and often two crutches to walk. The older the patient, the more difficult it is to walk with a resection arthroplasty.

Hip Fusion

Hip fusion or arthrodesis is an operation where inducing the bone to grow across the joint ends the motion of the hip. It was once an operation used to treat very young patients with severe arthritis. Today, I no longer see any use for it. Although hip pain disappears after this operation, a severe limp due to loss of hip motion is permanent. After many years, arthritis in the knee and back begins to develop because these joints are overstressed.


Hemiarthroplasty is when half of the hip joint is replaced. It is always the femoral rather than the acetabular half that is replaced. There are two versions: hemi resurfacing and endoprosthesis.

Hemi resurfacing was once used for stage 3 osteonecrosis. But now that total resurfacing is available, there is no longer any role for hemi resurfacing. Pain relief is incomplete in active people when only the femoral side is resurfaced, even when the acetabular cartilage is normal.

Endoprosthesis is still a useful option for elderly people who suffer a femoral neck (hip) fracture. If the patient is very active a stemmed total hip is superior, but if the patient is not very active, an endoprosthesis is a better solution.

Special Studies

To assist us in selecting the most appropriate method of treatment, additional studies may be required on an outpatient basis. For the studies noted below, our office will gladly assist you with scheduling.

Click on the headings below to learn more about each additional study.

Magnetic Resonance Imaging (MRI)

Magnetic Resonance Imaging (MRI) is a very useful study, but it is often overused as well. It is well known that there are many false positives and false negatives. Often physicians who are not orthopedic surgeons order expensive ($1500) scans when a simple x-ray would tell an orthopedic surgeon what the problem is. Most general physicians are not used to interpreting x-rays on their own. In this instance the MRI is just wasted money. In my opinion, musculoskeletal MRI s should only be ordered by orthopedic surgeons after they have evaluated the patient (cost $300). This would result in large health care savings.

Many people believe that you cannot have an MRI if you have implanted metal. This is not true. Most implanted metals are not ferromagnetic and are not affected by the MRI magnets. The exceptions are metal fragments that get into the body accidentally, including shrapnel as well as cardiac pacemakers. Hopefully MRI compatible pacemakers will soon become available.

If an MRI is taken around an orthopedic implant there is no danger to the patient. The metals we use: stainless steel, cobalt chrome, and titanium are not magnetic. The problem with scanning around an implant is that artifact is created around the implant on the diagnostic image. This artifact makes the image difficult to interpret. New software to eliminate this artifact have been developed and are called metal suppression or metal artifact reduction sequences (MARS). Not all radiologists are familiar with these, and useless scans around implants are still occasionally performed. The radiologists that I use are well versed in these techniques, but sometimes patients who don’t live here need to get scans done near their home. I suggest finding a larger center that employs a musculoskeletal radiology subspecialist who is likely to perform the scan correctly.

In most cases of moderate to severe arthritis an x-ray is all that is needed to make the diagnosis. Hip dysplasia, various impingement deformities, and stage 3 and 4 necrosis are also best evaluated by simple x-rays. A hip MRI is a useful study to look for problems such as stage 1 and 2 osteonecrosis, hip abductor tears, and labral tears. An arthrogram MRI (dye is injected into the joint prior to the MRI) is better when we look for a labral tear.

MARS MRI and Metal Suppression CT

MARS MRI and metal suppression CT are useful for diagnosing metal adverse wear failures (AWF) if metal ion testing shows excessive elevation.

I also use MRI prior to knee replacement surgery to create 3 dimensional virtual models of the operative leg and plan the knee replacement surgery. The company that provides this service creates sterile custom guides according to my protocol that are used in surgery to improve the accuracy of the bone cuts resulting in more reproducible alignment of the implants.

Finally MRI are very useful to evaluate the lumbar spine for arthritis, herniated discs, and stenosis. These conditions may cause referred pain to the hip area confusing both the patient and the orthopedic surgeon. This is particularly useful after hip replacement if there is residual buttock, lateral hip or sciatic type pain.

CT Scans

CT scans are also very useful to evaluate for adverse wear failure (AWF) around metal bearings in certain circumstances. Similar to simple x-rays, but unlike MRI they do expose the patient to a low dose of x-rays. They are less costly and allow imaging of both hips simultaneously. Metal suppression techniques also need to be used.

We are currently working on advanced techniques to accurately measure implant positions in 3 dimensions on these scans. We hope this will eventually allow us to develop more accurate guidelines as well as surgical guides for implantation during surgery.

DEXA Scans

DEXA scans (dual energy x-ray absorptiometry) is the test we use to measure bone density. The result is reported as a T-score, which is a way to compare a patient’s bone density to a normal young population. Because bone density varies according to race and gender, different normal populations are used. A T score between 1 and -1 indicates that your bone density is within the range of 90% of the 26 year old normal population of your reported race and gender.

If you Tscore is below -1.5 you are said to have osteopenia. If it is below -2.5 you have osteoporosis. This means weak bone. These cutoff levels are arbitrary. The lower your bone density, the higher your fracture risk. Osteoporosis, unlike osteoarthritis, is not painful. Pain occurs when a bone breaks. Bone density gradually decreases for the entire population with age. Women can have a more rapid rate of decline in their bone density for the first 5 years after onset of menopause. All women should have a baseline DEXA scan when they start menopause and this should be repeated at least once 2 years later.

To better understand osteoporosis I will use the analogy of high blood pressure. Neither condition is typically symptomatic. Left untreated, these conditions will eventually lead to severe medical problems; heart attack and stroke on the one hand, and fractures on the other. Both conditions can be treated to prevent later complications. Numerous medications are now available to treat low bone density. There is not complete agreement at which point treatment should be recommended.

I obtain DEXA scans on every patient on whom I perform a joint replacement operation. The cost is low ($150). We have found that this test is very predictive of certain complications that can develop after surgery. Sometimes even very young patients can have low bone density. In hip resurfacing we use the result in determining the risk of postoperative femoral neck fracture and determining how to precisely prepare the socket in surgery. Patients who have weaker bone are treated with anti resorptive medication and a longer period on crutches after the surgery. We have reduced the rate of the complication of femoral neck fracture from 1-2% to 0.1% using this strategy.

Metal Ion Level Testing

Metal Ion Level testing is a valuable way to screen for excessive wear of metal bearing implants. We recommend routinely measuring cobalt chromium and titanium levels 2 years after surgery on every patient in order to discover adverse wear failures early. In certain patients we recommend repeat monitoring thereafter. Most patients with metal bearing hip replacements as well as metal-plastic bearing knee replacements have some elevation of cobalt and chromium in their blood. There is no known problem caused by this.

Speculations of increased cancer risk have been disproven by numerous long-term studies. There is no evidence that kidney damage can occur due to circulating ions, but abnormal kidney function can lead to ion level elevation in the blood. There is no agreed upon acceptable level for joint implant patients. The normal levels in patients without implants is about 2 ug/L. We have done extensive studies on metal ion levels. The lowest level we have seen associated with an adverse wear failure (AWF) is 15ug/L. Sometimes a level higher than this is seen without evidence for AWF.

Implant loosening may be another failure mode that can be associated with elevated levels. There have been a handful of case reports of generalized systemic side effects possibly caused by very high metal ion levels. We have seen more than 10 AWF cases with levels between 50-200ug/L and none exhibited any systemic symptoms. It appears that systemic effects do not occur at levels that are typically seen in well functioning cases, and are even rare with very high levels seen in AWF cases. We obtain levels at 2 years because it is known that implants go through a run-in wear period of 1-2 years. Less is known about what is an acceptable level during this time. The earliest time that we have ever seen an AWF is after 2 years; it takes time to develop these problems.

We currently recommend metal ion testing:

  • Routinely on all patients at 2 years postop
  • When evaluating a painful hip implant
  • Prior to performing a second hip surgery on the opposite hip
  • Repeat levels periodically if levels are above 10ug/L, there is a steep acetabular inclination angle, the patient has a recalled DePuy ASR implant

We recommend obtaining a metal suppression CT or MARS MRI whenever we encounter a ion level above 10ug/L. Significant soft tissue inflammatory mass (not cancer) or large fluid collections indicate a probable AWF. All case of AWF so far have occurred in cases where the acetabular inclination angle is above 50. But only 5% of patients with AIA>50 develop AWF.

Bone and Indium Scans

Bone and Indium scans are performed by removing some of your own blood and labeling it with an isotopic material that is then re-injected. You will return one day later and the area of the joint will be scanned. These tests help us evaluate for loosening of implants or for infection. The amount of radiation is generally not much more than a single x-ray exposure. Complications have been minimal. Computerized scanning is sometimes combined with injection of these agents to better define the changes in a three-dimensional way.

Aspiration & Arthrogram

Aspiration & Arthrogram is typically done to obtain information about the presence or absence of infection, particularly if you have had previous surgery. The radiologist may be able to aspirate fluid directly from the hip joint, which will provide valuable information. These samples can be analyzed by cell counts culture gram stain and PCR (a DNA test for bacteria).

Final culture results are usually available in 7 - 10 days. In general, these procedures are not very painful; local anesthesia is utilized in the skin. On occasion, mild discomfort may be associated with the study. Most often it is transitory and usually can be relieved by medications.

Blood Tests

Blood tests such as CBC, CRP, and ESR are sometimes done as screening tests to rule out infection. If they are positive we usually follow this up with either an indium scan and/or aspiration.

Planning for your Surgery

In order to make sure that your procedure goes well and you are prepared, please click on the headings below to learn more about what you need to do to plan for your surgery.


Certain medications are known to increase bleeding. It is usually advisable to stop these before surgery to reduce the risk of complications.

These include:

  • aspirin
  • anti-inflammatory medications (over 30 different drugs such as ibuprofen and naproxen that may be over the counter or prescription)
  • anti platelet agents ( such as persantine, plavix, aggrenox)
  • anticoagulants (such as Coumadin, lovenox, pradaxa, xarelto)

If you tell us everything tat you are taking, we will inform you how long before surgery they must be discontinued. In patients who require long-term anticoagulation we usually stop these for a short time prior to surgery and then gradually resume them.

Over the counter supplements may contain chemicals that interfere with anticoagulant medication. They are not well studied; dosing is inexact and drug interactions are poorly understood. Therefore it is best to stop taking these one week prior to surgery and resume them only after we discontinue your routine postoperative anticoagulation.

You may continue Tylenol, celebrex and narcotic pain medication until the day of surgery.

Home Exercises

Obtaining crutches or a walker and practicing walking with these before your surgery is very helpful. With an arthritic hip or knee joint, exercise may be painful. You may have developed muscle atrophy due to disuse. No special preoperative program is needed. Swimming, water exercises, elliptical and exercise biking are usually the best tolerated exercises with an arthritic joint.

After your surgery, we will recommend a period of light activity while you start to heal and then allow you to increase progressive exercises. In most cases, muscle atrophy is reversed by one year after the surgery. Arthritic joints also become very stiff (loss of motion). There is not much you can do about this prior to surgery.

Physical therapy (PT) has no proven benefit. If the knee gets very stiff prior to surgery this is only partially correctable with extensive postoperative PT. In the hip, on the other hand, motion returns spontaneously without PT and near normal range of motion is recovered by one year postoperative.

Weight Loss and Diet

Weight loss is helpful prior to surgery if you plan far enough in advance. Surgery is technically more complex as obesity increases. If your BMI is greater than 40 (morbidly obese) hip resurfacing is no longer possible; even stemmed total hip replacement is challenging. Risk of postoperative complications including infection, venous thromboembolism (blood clots), fracture, and even cardiac complications is significantly increased. I will operate on even the morbidly obese, but you must understand that you are putting yourself at higher risk by going into surgery too heavy.

I recommend weight watchers, a Mediterranean diet and aerobic exercises. You must avoid all forms of sugar, artificial sweeteners and processed carbohydrates (white bread, white rice, regular pasta and potatoes), fried foods and limit animal fats. Whole grains, nuts, limited fruits and healthy plant oils such as olive oil and canola oil and small quantities of lean meat can be the basis for a healthy nutritious and extremely tasty diet.

There is now ample evidence that you actually feel more satisfied and less hungry if you eat this type of food than if you consume larger amounts of empty carbs. This not only makes it easier to loose weight, but also this diet reduces your cardiovascular risk. This food also tastes much better than typical American food once you learn how to prepare it properly. Despite their name, Olive Garden does not serve a Mediterranean diet!

Most diet pills and diet programs are unhealthy and/or are a gimmick to take your money. Body fat is essentially a biological battery that stores energy. You must burn more energy than you take in if you want to burn off the energy in the battery and loose weight. It is a simple concept. Anything else that advertisers concoct prays on peoples’ wishful thinking. There is no magic solution. The concept is simple, but achieving sustained weight loss is a difficult task that requires strong will power and usually a willingness to unlearn all the bad dietary advice we have gotten from our culture.

Over the last 50 years our industrial food industry has figured out what to do to food to want to make us subconsciously overeat and thereby increase their sales. Adding salt and sugar or artificial sweeteners to everything including vegetables and meat, makes us overeat. Highly processing all carbohydrates causes rapid breakdown and absorption in our gut after a meal resulting in high spiking blood levels of sugar followed by high insulin output by our pancreas and a sudden crash in our blood sugar levels. This not only damages our pancreas over time and causes diabetes, it makes us crave more food hours after we have just overeaten. Adding fat to food increases its taste to us especially if this is unhealthy animal fat. Trans fats are manufactured from healthy plant fats as a substitute for animal fats, but they have been found to be even unhealthier than animal fats.

Beyond weight loss, a healthy diet would avoid pesticides, genetically modified food, as well as all animals raised on an unnatural corn diet. Almost all farm-raised animals from chickens to beef to fish are now fed on corn diets that increase their ratio of omega 5 to omega 3 fats that they contain. This makes them unhealthier for us to eat. The solution for this is to eat organic food and grass fed animals and wild fish whenever possible. The cost of these foods is higher, but ultimately the health benefits to our environment and us will be immense if we can force our food industry to change.

Buy the good stuff whenever you can, eventually, as our food industry will be forced to change it is likely that prices will come down. Most people who read this can easily afford to pay even double the price for their food. But this is not necessary. Just eating out a few times less will enable most people to buy healthier ingredients to make these healthier foods for themselves. You are what you eat. Most health care dollars in the US could be saved if people ate healthy reasonable amounts, exercised regularly, didn’t smoke and drank alcohol in reasonable amounts.

Home Preparation

After your surgery you will be using either a walker or crutches. If you are younger and have good upper body strength you will prefer crutches. If you are older, have weaker arms or are obese you may find a walker easier. You should try these around the house and make sure important areas (bathroom, kitchen, and bedroom) are easily accessible. You may need to rearrange furniture or temporarily change rooms for your convenience after your surgery. Remove all throw or area rugs that could cause one to slip. Bathroom modifications that may be helpful include a shower chair, gripping bars, flexible shower handle, non-slip floor surfaces or mats, soap bars with a string attached and a long-handled scrub brush.

If you live alone, you may want to make arrangements to have a friend or relative stay with your for a few days after your surgery. This is especially useful in meal preparation, carrying various items such as plates and cups, and putting on socks. It may be helpful to wear shirts with pockets and/or to drape a small canvas or plastic bag over your shoulder for carrying smaller items.

If you have no one who can help you at home, most insurance carriers will pay for 1-2 weeks in a rehabilitation facility. I prefer that patients make arrangements to stay home whenever possible because staying rehabilitation facilities increases your risk of infection. Home health aides can be hired for 1-2 weeks at relatively low cost ($15-20/hour), but insurance does not cover this cost. Sick people congregate in hospitals and rehab facilities. My goal is to get people out of the hospital quickly in 1-2 days and avoid rehabilitation centers altogether to minimize risk. We are now even able to perform some hip and knee replacements in healthy younger patients as outpatient procedures at our ambulatory care center and avoid the hospital altogether.

Studies have shown that outcomes for joint replacement are better in high volume centers. But most high volume centers are at large hospitals where very sick people with resistant bacteria congregate. Actually, outcome is more dependent on the surgeon than the hospital. I think a high volume surgeon who performs surgery in a smaller hospital or outpatient setting is the best of both worlds. Proof for my position is that my deep infection rate is 0.1%, while the national average is 1-2%.

Medical Evaluation

(at least one month prior to surgery is recommended)

Hip replacement surgery is a major procedure and care must be taken that you are in the best medical condition. You must see your regular medical physician within a few months before your surgery. He or she will perform the necessary tests. We will provide you with a minimum list that we require, but your physician may need to perform additional tests before you are cleared for surgery. Surgical clearance by your medical doctor does not mean that he/she or I guarantee that you won’t have a complication. It is just our attempt to make sure you are in the best shape possible prior to surgery.

If necessary, your physician can “tune you up” prior to surgery. We prefer that you see your physician at least one month prior to surgery. If you have your evaluation too close to surgery this leaves us very little time to do unexpected but necessary follow-up testing (for example a cardiologist consult) or correct abnormalities such as anemia prior to surgery. This may lead to postponement of surgery or it may tempt you to accept suboptimal preparation to keep a surgical date. Some people have problems that put them at higher risk that cannot be fully corrected. This does not mean that they cannot have an operation. They must just weigh the higher risks with the benefits and make their choice if it is worthwhile. Some people have conditions that are correctable and place them at higher risk (obesity), but feel they are not willing or able to change.

Others have conditions like diabetes that has lower risk when tightly controlled, but they are unwilling and unable to comply with optimum treatment. They are accepting a higher risk. This is their decision. Patients older than 80 are known to have a 25% chance of major medical complication after joint replacement surgery. Most of these can be managed with a reasonable outcome. Even older patients who have been told by their doctor that they are very healthy for their age have a higher risk simply because of their age. At age 80 your heart is not as strong as when you were 20, no matter what anyone says.

Surgery is a major stress on your system that can cause any number of medical complications. Each patient in consultation with their regular physician must weigh the risk and benefit. If a patient has had a medical clearance and has accepted the risks, I only decline to perform elective surgery in extreme cases where I still think it is very unreasonable. Please have your regular physician send his/her clearance as well as all test results to us. We need to review them, as does the anesthesiologist who is involved in your operation. If you don’t have a regular physician and you live in the Columbia metro region, we may can assist you in getting an appointment with a local physician.

You need to be seen in our office approximately within a week of your surgery. At this time we will review the proposed surgery with you, make adjustments to your plan of care dictated by your preferences and particular medical problems and to answer any last minute questions you may have. At this time you may purchase crutches and ice machine to use after surgery, at low cost, in our office. We will also give you all prescriptions that you will need after surgery in advance.

You should have them filled at a local pharmacy before the operation. Long’s Drug carries all the medications that I routinely use. Delays may occur if you try to fill them elsewhere. Delays and hassles may also occur because some insurance companies deny paying for certain medication or require additional precertification prior to filling certain prescription. They always try to imply that there is something that the doctor has done wrong that causes the denial. This is a highly irritating practice of some insurance companies. They are not experts in medical care and shouldn’t be making decisions about medications. Their behavior also significantly increases the costs of providing your care. It is their shortsighted attempt at trying to avoid paying for medical costs for which you have paid high insurance premiums all these years.

We provide your prescriptions in advance so that these insurance headaches can be resolved in advance of you leaving the hospital. In an attempt to provide a more seamless service, patients having outpatient surgery at our ambulatory surgery center will receive all medication (already included in surgery center fee) from our center. By law, many narcotics cannot be filled across state lines, so be sure you get them filled here before you return home to another state.

It is imperative that you not eat or drink anything after midnight (12:00 AM) the night before surgery. This helps to prevent potential nausea and vomiting from occurring during surgery that could cause complications.

What to Bring to the Hospital

For a reasonable fee we sell crutches, an ice machine and a hip kit, which contain helpful devices such as a leg lifter and a grabber. You can purchase these at the time of your preop visit at our office and bring them to the hospital. The hospital discharge planner can secure devices such as walkers raised toilet seats, and the commode seats for you, or you can purchase them in advance from a local medical supply store. A cane can be purchased cheaply at most drug stores.

If you do not wish to wear the hospital gowns, bring some loose fitting clothes and/ or sweat shirts and pants and a robe and some slippers. Bring your toiletries as if you were going to a hotel. Bring reading material and a computer; Internet access is available. Leave jewelry and other valuables at home. Bring all of your prescription (not vitamins and supplements) medicine bottles; our pharmacy wants to confirm dosages directly from these for the hospital record to minimize chances for a mistake.

Preoperative Office Visit

Within the last week or two prior to surgery, we will ask you to see us in the office for a final check prior to surgery. We will review your preparation and be sure all of your questions are answered, and finalize our management plan. Local patients have already been evaluated by Dr. Gross previously and will just need a final review by Lee Webb N.P.

We will ask you to purchase crutches, an Ice machine and a hip device kit for a reasonable price at this time if you don’t already have these. We will teach you how to use them. We will provide you with all of the prescriptions that you need after hospital discharge. We strongly recommend that you fill them in advance at Long’s pharmacy across the street from the hospital.

They keep all of the medications that we use in stock so it is convenient. Not infrequently, insurance companies create hassles and delays when you try to fill a prescription. Starting the process in advance insures that these insurance company gimmicks can be resolved before you are ready to leave the hospital. We want your discharge to run smoothly. In addition, it is important to realize that most narcotic prescriptions must be filled here in South Carolina; the law does not allow pharmacies in other states to fill them.

Out of state patients who I have only spoken to over the telephone, will undergo a full orthopedic evaluation. We will obtain up to date and specialized x-rays that allow us to accurately position your implants in surgery. We will answer all of your and your caregivers’ final questions at this time.

We see patients only at the Lake Murray Blvd office of Midlands Orthopaedics. It is located in the northwest suburbs of Columbia directly off of interstate 26. The Hospital that we use is Providence NORTHEAST (not main Providence), which is located on Gateway Corporate Blvd in the northeast Columbia suburbs off of interstate 77. It is about ½ hour drive from the office. When we perform outpatient surgery it is done at the Midlands Orthopaedics Surgery center adjacent to our main office near downtown Columbia on Blanding street, also about ½ hour from our northwest office.

The Operation

Prior to your hospital arrival, the anesthesia staff has prepared a preoperative record for you based on information that you, your medical doctor, and I have sent them. On the day of surgery, the anesthesiologist will perform a final review of this record. You will be taken to the preoperative holding area for final preparations. You will change into a hospital gown. The staff will confirm data, take vital signs, and clarify any remaining items. They will insert an intravenous line, draw blood and perform an initial preparation of the area of operation.

You will be asked to sign a hospital consent form for the operation. We have already discussed your operation in the office in detail and answered all of your questions in advance. You have already signed a very detailed consent form in my office. The anesthesiologist will discuss your anesthesia options and answer your questions about these. We will draw a small vial of blood from your IV that will be processed into platelet concentrate and later sprayed into your surgical wound to enhance the healing process. We will ask you to confirm the side of your surgery and mark this with an indelible marker while you are awake to prevent wrong site surgery.

You will be given a number of medications prior to the operation. We utilize a multimodal pain management protocol to minimize your postoperative pain. The first step is to load your system with anti-inflamatory medicine, IV Tylenol, long-acting narcotics, and three anti-nausea medicines before we start the operation. We will also administer an IV antibiotic just prior to starting the operation.

Your partner can stay with you in the preoperative holding area until you are taken to the operating room. At that point, your partner will be directed to the waiting room where I will look for them immediately after the operation to inform them of the result.

You will be taken to the operating room on a stretcher. At that point, anesthesia will be administered. During the entire time in the operating room, a specialized nurse anesthetist (who works directly under the supervision of the anesthesiologist) will carefully monitor you throughout the operation. Once you are under anesthesia, a catheter will be inserted into your bladder, when you are not aware of it. This will usually remain in place overnight to drain you bladder to protect it and to monitor your fluid balance.

If we remove it too soon before the spinal anesthesia has completely worn off, your bladder will not function properly and we will need to reinsert the catheter. Therefore, we usually leave it in overnight the first night and remove it first thing in the morning. Inserting a catheter under anesthesia is painless; removing a catheter the next morning is virtually painless, inserting a catheter on the nursing floor is quite uncomfortable. Next, you will be positioned on the operating table, braced into place and the operative site will be prepared.

My preference is spinal anesthesia with sedation because the recovery is smoothest and least painful with this technique. Safety of spinal and general anesthesia is similar. There may be certain situations where the anesthesiologist feels that one type is better, and you should follow their advice. Usually both types will work, and it is your choice. In a spinal anesthesia, a very thin needle is inserted into the fluid around your spinal cord in the lower back and local anesthetic medicine is injected. The exact type of medicine that the anesthesiologist chooses, determines the duration of the effect. Your legs will become completely numb and you will not be able to move them. The anesthesiologist will give you a sedative prior to the procedure so that you won’t be uncomfortable.

Once the spinal anesthesia has taken effect, the anesthetist will administer additional sedatives through your IV so you sleep through the operation. They will monitor you and administer medication as needed. If the spinal does not work properly, the anesthesiologist will then convert to a general anesthesia technique. This is required in less than 1% of patients. The surgery can be performed under spinal with you fully awake because your legs are numb, but I don’t recommend this. You can tell the anesthesiologist how deeply you prefer to sleep. Most people choose heavy sedation; they wake up in the recovery room only vaguely remembering that they bent over to get a spinal.

After you are under anesthesia and positioned and prepped and draped, I enter and perform the operation. Before starting, we always confirm the operative site by the marks we placed on your skin earlier, and we review the written paperwork. Lee Webb, my nurse practitioner, is usually my first assistant in the operation. I always perform the operation personally. No residents, fellows or other surgeons will ever perform the operation. Usually, two surgical technicians are scrubbed in to assist. A circulating nurse is in the operating room to assist as well. The nurse anesthetist continues to monitor you and consults with the anesthesiologist as needed.

Details of your specific operation were discussed with you prior to surgery. Whenever possible, I perform minimally invasive procedures. Patients who are large, have previous scars or complex deformities, or need revision surgery typically require larger incisions. My standard hip incision is 3-5 inches long, while knee incisions are 4-6 inches long. Because I use minimally invasive techniques and a tissue sealer device, blood loss is low, and less than 1:1000 need a transfusion. The national rate of transfusion for joint replacement is 30%. In selected cases, we use a cell saver that can process and allow us to re-infuse blood lost in surgery. Usually, we do not lose enough blood to make this practical.

At the end of the operation we spray your tissues with platelet concentrate processed from your own blood to speed up the healing process. We also inject local anesthetic to reduce postoperative pain. In addition to the IV antibiotics that you receive, we irrigate your wound copiously with a dilute betadine solution with a jet lavage and place concentrated antibiotic powder directly into your wound. We operate in an ultraclean operating room with over 25 complete filtered air changes every hour. All personnel that are scrubbed wear a personal body exhaust system that prevents them from shedding bacteria into your wound. Your tissues are closed with multiple layers of absorbable sutures. They usually dissolve in about 3-4 months.

All sutures are under the skin; none require removal. We then place a silver impregnated antibacterial dressing over your incision that will stay on for one week. This further protects you from infection. It also makes it convenient to shower immediately after the operation. With the comprehensive infection prevention program that we have developed, my deep infection rate is 0.2%. The national average for joint replacement is tenfold higher.

Over many years of perfecting our techniques we have developed a program that allows us to perform a joint replacement with minimal pain, low blood loss, rare infection and a rapid recovery.

Multimodal Pain Management Protocol

RESULTS – Minimal pain, 1-2 day hospital stay, no rehab center; Outpatient joint replacement in selected patients

NATIONAL BENCHMARKS – 3-5 day hospital stay plus rehab center

Comprehensive Blood Management Protocol

RESULTS – Less than 1:1000 transfusion rate; Most revision surgery without transfusion

NATIONAL BENCHMARKS – 30% transfusion rate higher in revisions

Infection Prevention Protocol

RESULTS – 0.2% deep infection rate

NATIONAL BENCHMARKS – 1-2% deep infection rate

Postoperative Recovery

Immediately following surgery, you will be taken to the recovery room where you will stay 1 to 2 hours. Your blood pressure, circulation, respiration, temperature, and wound drainage are carefully monitored. Patients may be transferred to an intensive care unit (ICU) for a day or two if close monitoring is needed. Most patients will be transferred directly to their own room. Private duty nurses are generally unnecessary. Once you are in a regular hospital room, family and friends may visit you. If you have a partner waiting on you during the operation, they will be informed when you arrive in your room. The room is modern and private with a private bathroom and configured to look more like a hotel than a hospital room; although all hospital functions are possible. TV and Internet access are available. Chairs and a fairly comfortable pull out bed for your partner are available.

When you arrive in your room the spinal anesthetic will still be in effect. You will not feel pain. Gradually over several hours the anesthetic will wear off; sensation and strength will return to your legs. You have been pre-loaded with pain medication to prevent severe pain. This medication will continue to be administered around the clock. However if you still start developing pain, you should alert your nurse, who can administer additional pain medication. You should stay ahead of the pain and request additional medication before it gets very painful. It is hard to catch up with the pain if you try to tough it out at first. We have you on oximeter and cardiac monitor for the first 24 hours. If you get too sedated from the pain medication, your nurse will not give you more. There are medications to reverse the effects of narcotic overdose if you get over sedated. Every person needs a different amount of medication. We start with a baseline regimen based on patient size, age and previous narcotic use. The protocol is then adjusted to your specific needs. Most patients require some additional oral medication over and above the routine scheduled protocol. Occasional a shot of morphine is required to get patients under control. It is very rare that pain is so bad that a PCA (Patient Controlled Analgesia) machine is required.

We use a multimodal pain management protocol to make you as comfortable as possible. The strategy is to use as many non-narcotic modalities as possible. But some narcotics are still required for 3-7 days after surgery. Narcotics cause most of the side effects. We give all patients routine anti-nausea medication, but if you are very prone to this problem several additional medications are on order and can be requested from your nurse as needed. The primary narcotic side effects are: nausea, itching, constipation, and mental changes including hallucinations. These are not symptoms of allergy. We maximize all non-narcotic methods of pain control. Other drugs are on order for you to request to minimize nausea, itching and constipation. But in the final analysis it is a balance between pain control and side effects. You have to determine how much narcotic you wish to take. When you go home you will get detailed written instructions in how to manage this protocol.

You will receive IV fluids until you are drinking enough. The IV catheter will be removed on postoperative day one immediately after your second dose of antibiotics if you are doing well. The catheter will also be removed from your bladder at this time. There are no surgical drains to remove or dressings to change. You will have a Sequential Compression Device (SCD) on your legs while you are bed for the first day to prevent blood clots. We will start administering a oral blood thinner 24 hours after surgery to prevent blood clots, after that you can stop using the SCD if you wish. In order to prevent respiratory complications you will be taught to perform simple exercises with an incentive spirometer and cough several times a day.

You will walk within 24 hours of surgery. As soon as your spinal is worn off the physical therapist will see you. Typically the first three patients operated on in a day will receive PT the first day. The later patients will rest overnight and begin PT first thing in the morning. I give the therapists detailed orders that allows them to teach you the correct protocol. Most patients are full weight bearing as tolerated with use of crutches for 1-2 weeks for support and a cane for 1-2 weeks thereafter. Patients with softer bone or complex deformities or revision surgery may have restricted weight bearing and require longer periods of crutch walking. Any type of crutches or a walker is equivalent in my view. It is a matter of patient preference. Walkers usually work better for older patients with weaker arms and heavy patients. The Physical therapist will teach you a few home exercises and a few precautions. All this will be written down in your discharge instructions. You will learn to climb stairs and get into a car. The hip resurfacings and large bearing total hips that I use are very stable and require minimal precautions dislocation is very rare with these implants. The hardest thing to do for the first week is just lifting your leg off the bed. Once you are in a sitting position you will easily be able to get up and walk. You will not really need assistance to do much on your own. After one week muscle strength already returns enough to move your leg well. As soon as you are walking well and are no longer dizzy you may shower. You should spend your day in a chair and walking around. Bed is for sleep only. Excessive Bedrest causes complications.

Patients who live within 4 hours drive of Columbia are usually discharged after 1-2 PT session on postoperative day one. Patients requiring longer travel are usually kept in the hospital for one additional day to be sure they are ready for travel. We are now offering this surgery as an outpatient procedure in our surgery center for selected healthy patients if their insurance plan allows it. Patients who live in the Columbia metro area can go directly home. We have a nurse check on you at your home in the evening and the following morning. If you don’t live in the Columbia area need to stay in a local hotel for 1-2 days if you elect to have outpatient surgery. Our protocols are now so good that outpatient surgery is feasible for many patients and is certainly cost effective. I never recommend a stay in a rehab facility unless a patient has serious co-morbidities and/or no one to help them at home. Insurance usually pays for rehab. A stay in a rehab facility increases your chance for a complication, particularly infection. It is my Philosophy that sick people congregate in hospitals and rehab facilities; healthy patients having elective joint replacement should minimize their stay in these. Some people who are medically able to go home from the hospital but have no help can hire a private duty nurses aide from an agency for $15-20 per hour. Insurance does not cover this. People who are flying from Columbia should plan one extra day in a hotel after discharge as an additional precaution (so travel plans don’t get cancelled if problems arise). Patients who are travelling by car can plan to begin their trip as soon as they are discharged from the hospital because they have more travel flexibility. You can’t drive yourself because you will be on narcotics.

At the time of discharge you will be given a detailed written instruction sheet that covers all aspects of your care. The nurse at the outpatient center or the hospital will review this set of instructions with you and your caregiver prior to discharge to make sure that you understand it. You will have an antibacterial sealed dressing in place that you can shower with. It will need to be removed after even days. All sutures are under the skin and dissolve.

After You Go Home

With advanced minimally invasive surgery, multimodal pain management, and comprehensive blood management protocols the need for a hospital stay has become almost unnecessary. We almost never transfuse patients and patients are comfortable and are able to walk independently very rapidly after surgery.

All patients will be discharged with a detailed written protocol that contains all of the instructions that they have been previously taught. This pamphlet allows you or your caregiver to review instructions if you forget anything. The written instructions apply to the first 6 weeks which we call phase I of your recovery. All of your medication will have been filled in advance of discharge.

Click the headings below to learn more about what to expect after your procedure and instructions you should follow.


Therefore anyone who lives within 4 hours drive from Columbia is typically discharged after only one night in the hospital. Your Caregiver can then drive you home. I recommend that you sit in the passenger seat of a mid sized or larger sedan with the seat reclined for the ride. This is no different than sitting in a recliner at home. You will be on oral blood thinner and should do your ankle pump exercises every hour. Getting out to walk periodically is optional. If you purchase a car charger, you can use your ice machine while riding.

People that live eight or more hours away may opt to fly instead. Most airlines will give you the bulkhead seat if you are handicapped and arrive early. You do not need a slip; they will take your word for it when you arrive on crutches. Be sure to pack your ice machine in your check-in luggage, but bring your medications on board with you. Carts are always available to transfer you at airports.

People who live more than 4 hours drive away are usually kept in the hospital a second night for their convenience. That way they can get an early start on their travels the following morning. If you are flying, I would recommend booking one night after hospital discharge at the Marriott Courtyard or Residence Inn close to the hospital or near the airport. That way, you will have some leeway in case your stay is prolonged due to some minor medical issue.

The Columbia Airport is small, attractive and efficient and is about 40 minutes from the hospital and 30 minutes from our office. But often only small planes fly out of here. You will often have to climb steps to get into the plane, but you will be capable of this. The other option is to fly out of the major Charlotte airport. It is about 1 hour and 15 minutes drive from the hospital and 1-½ hours from our office.

Outpatient Surgery

Selected healthy patients can also opt for outpatient surgery at our surgery center. Currently we only have a contract with Blue Cross for this option. You will stay in the surgery facility for about 8 hours. When your anesthesia has worn off, you have voided, and you have walked with the therapist you are discharged home. Local Columbia metro patients can go directly to their home. Patients from outside the area will need to stay at the Marriot Residence Inn with a caregiver for one night or two nights if they live more than 4 hours drive away. A home health nurse will visit you the evening after the surgery and in the morning. She can administer a shot of morphine or run a bag of fluid if needed. This is rarely required.

Pain Control

Our protocol is very effective and patients are usually very comfortable. Every patient responds differently to medications. We follow a multimodal protocol that can be adjusted, as needed depending on individual patient response. We combine numerous agents to limit postoperative pain and keep our patients as comfortable as possible. The person who has taken a lot of narcotics before surgery is the hardest hit with pain afterwards.

On the other hand, sometimes people feel so comfortable that they stop all the medications when they leave the hospital and then pain catches up. We generally recommend 3-5 days of long-acting narcotic after surgery together with occasional short-acting narcotic as needed. In addition, round the clock Tylenol for 1 week and an anti-inflammatory medication for at least 2 weeks is recommended. An ice machine should be used regularly for 1 week.

True allergy to narcotics is rare indeed. Common side effects include nausea, itching, constipation, and mental changes. Some people are more sensitive to these side effects. They still need narcotics for surgery. Our protocol includes medications to limit these side effects. If narcotic dosage is decreased, side effects lessen, but pain increases. The patient must choose the right balance.

Switching from one specific narcotic to another is generally less effective than adjusting dosage. All narcotics cause these side effects; they are dose dependent effects. Certainly you need narcotics while you travel home. After 3-5 days surgical pain is usually to a point where narcotics are not needed on a regular basis.


You should be up out of bed the full day. If you are tired you can take a nap. Otherwise you should not be in bed. You should basically hang around the house like a very lazy weekend day. You should get up and walk around frequently with you crutches. You can read watch TV or use the computer. You will be on narcotics for about 3-5 days after discharge, so your thinking may be muddled and you may be a bit groggy.

You should walk for exercise twice daily. At first, in the hospital, you are walking several hundred feet. You should gradually increase the walking distance at home until you are walking one to 1-1/2 miles a day by week 6. You will be able to climb stairs as well. Most people are able to start going foot over foot with the rail by 4-6 weeks. Most patients use crutches for 2 weeks and then a cane in the opposite hand for another 2 weeks.

Don’t try to advance more rapidly than our instructions recommend. You won’t heal faster with more exercise; you will just risk hurting yourself. We have seen patient break their wound open, severely strain their weakened muscles or even get a stress fracture with too much activity too early. If you don’t do much, there will be no harm; there will be plenty of time for vigorous exercise when you are more fully healed. No impact activities or lifting more than 50 pounds are allowed for the first 6 months; thereafter restrictions are lifted.

As soon as you have stopped taking narcotics, you may drive. You should use an automatic car with the right foot on the gas pedal. If your right leg was operated on, you need to be comfortable using the left leg on the brake for about 6 weeks. This is because in an emergency, it is difficult to slam the foot of the operated leg on the brake hard and fast enough. Most people can resume normal driving at 6 weeks.

Most people return to office work at 2 weeks after surgery. For doctors, dentists and others who spend time standing and walking, a lighter schedule is recommended starting at 2 weeks after surgery. Pilots can return to flying at 6 weeks. People who have jobs that require walking can do this at 6 weeks. Deep bending squatting heavy lifting and impact activities (running, jumping, sports) and heavy labor are not allowed for 6 months.

Slow-down Program

Some people will require a modified slowed down program of recovery. Typically this is required in people who have weaker bone, severe under lying deformities or significant bone loss prior to surgery. I can resurface most bad hips, but in the more challenging cases, a slower initial program is required to avoid complications. Most patients who fit in this group will still have an excellent outcome and be able to fully participate in impact sports after 6 months just like the more ideal candidates. The slow down program involves 6 weeks of crutches, one month of a cane, and limited walking until 6 months.

We do a complete bone strength analysis with a DEXA scan before surgery. We also measure vitamin D levels on all patients. About 40 % of the population is deficient. Long-term deficiency weakens the bones. In young men who are found to have low bone density we recommend having your doctor check your testosterone level and consider supplementing it if it is low. Our research has shown us that low bone density is the one factor that is most strongly linked to the two most common early complications of hip resurfacing: femoral neck fracture and femoral head collapse (some call this necrosis). We call these early femoral failures because femoral neck fractures always occur within 6 months of surgery and head collapse is almost always seen by the 1-year x-ray.

The only other factor that we have found to be linked to early femoral failures is body mass index (BMI) over 30. It does not matter if BMI is elevated because of fat or muscle. In my first group of 373 resurfacings we had about 2% early femoral failures. In the last one thousand, we have had one single case. This 20-fold improvement has been achieved by research into the causes of these complications and development of patient stratification protocols; NOT by patient selection. Many experts recommend doing resurfacing only on the “best candidates” (patient selection). We have instead taken the approach to modify patient management to allow all patients to benefit from resurfacing. Because we have nearly eliminated these complications, we have even expanded the indications for resurfacing to nearly all age patients.

Basically, the protocol is to measure the DEXA scan. If patients have a T score in the operated femoral neck less than 0, then they are given an oral bisphosphonate drug weekly for 6 months. If the T score is less than -1.5, we recommend a one-year bisphosphonate course as well as a longer period on crutches. If the BMI is 30 or greater we also recommend a 6onth course of bisphosphonates. There are other alternatives to bisphosphonates if you cannot tolerate these, but sometimes insurance companies are reluctant to pay their higher costs.

Position Restrictions

A raised toilet seat and seats built up with blankets are helpful for a few weeks until muscle strength starts returning. It is more difficult to rise from a lower seated position at first. Even though the hip bearings that we employ are larger and more stable, extreme bending past 900 is still best avoided for the first 6 months until the hip ligaments are healed. It is safe to put on shoes and socks whenever you are comfortable to bend your hip enough provided you keep your knees apart when bending over.

Pillows between the legs are not required, but many people find this more comfortable. Laying on the incision causes no harm, but will be uncomfortable at first. After 6 weeks, bending past 900 is allowed, but deep squats and flexion exercised should be avoided until 6 months after surgery. After 6 months only extreme forceful flexion of the knee towards the opposite shoulder should be avoided.

Rehab / PT

I strongly recommend against stays in an inpatient rehab facility. The only time that I think this is required is in patients who are unable to arrange for any help at home, or those that have severe compounding disabilities that make walking with crutches extremely difficult. It has been shown that patients going to rehab units have a significantly higher risk of infection. Sick people tend to congregate in these units; it is best to stay away from them. If you need extra help that family and friends are not available for, home health aides can be hired from a home health agency to come assist you. In the Columbia area this costs about $17 / hour with a 3-hour daily minimum; insurance does not cover this.

Formal Physical Therapy is not required after you leave the hospital. The exercises are easy to perform on your own. We teach them to you in the hospital and send you home with an instruction sheet. At 6 weeks we advance you to the phase II program which is also easy to learn and to perform without supervision. If you see me in the office for the 6-week follow-up, we will instruct you in the phase II exercises, if you choose remote follow-up, you will arrange for a one-time visit with a PT to learn the phase II program. If you insist, I will provide you with a physical therapy prescription for more than one visit after 6 weeks. In the typical case extra PT is a waste of money, in some special circumstances it can be helpful.

Wound Care

I use a posterior approach. The incision is just back from the side of the hip. You will not sit on your scar. My total hip incision is 3 inches and my resurfacing incision is 4 inches in length in 95% of patients. Patients with BMI >35 or with old hip scars or with more complex anatomy sometimes require longer incisions. We use only internal stiches. This leaves a nicer scar and avoids suture/staple removal. We apply a 10-day antibacterial silver sealed dressing. This should only be removed early if it peels off or there is excessive drainage. You can shower over this dressing, but should not soak it in a tub.

After this initial dressing is removed (10 days after surgery) you may shower with your skin exposed. You should pat it dry and apply a small amount of bactroban (mupirocin) ointment daily until the wound is fully sealed and no scab or drainage occurs. If there is any drainage, the draining area should be kept covered by gauze dressing. You should notify us if there is any drainage after 2 weeks. Bruising and some redness are normal for a few weeks, if you are concerned, call us and e-mail us a picture. In rare cases there is a lot of early drainage. If this occurs, the initial silver dressing may become overwhelmed and require removal.

In this case you should apply bactroban daily, together with a thick gauze dressing. If drainage does not resolve after 3 days please call us for further instructions. Although minor wound problems are common and can be easily managed, serious deep infections are very rare (< 2/1000 cases in our practice). Even with these rare cases, the implant can usually be salvaged with aggressive management. After 6 weeks the wound is usually healed enough to allow soaking in a tub or swimming.

After 6 weeks you may also apply any creams or ointment that you desire. Although there are many advertised wound-healing creams, there is no good evidence to support this practice. Your incision will gradually fade over a period of 1-year, if you apply a special lotion it will not change this natural process. Due to subcutaneous fat atrophy at the incisional site, a small depression is usually present after all swelling has resolved at 6-12 months after surgery. This a cosmetic issue that sometimes bothers women. We have found no way to prevent it. It is not a sign of underlying muscle atrophy. We have done MRI scans in many patients and the gluteus maximus is always similar in size to the opposite side. Massage around the operated hip can be resumed after 6 weeks.


Every patient’s recovery is different; therefore we can only give you a general description of what is normal. If you are concerned that you may be having a complication, please don’t hesitate to call us at any time. Most questions can be answered over the telephone or via the online patient portal if you prefer. A physician is always on call to handle emergencies, but they will not be able to answer questions about our protocol or instructions, for these you will need to consult my nurse during regular business hours.

On-call doctors are also not authorized to call in any narcotic prescriptions. You will have to go through the inconvenience of going to the ER if you need these and have not planned in advance. Refills for narcotics must be arranged through my nurse during regular business hours. It is rare that refills are required because we provide a generous amount at the time of discharge that almost nobody uses up.


Routine follow-up is at 6 weeks, 1 year, 2 years and every other year thereafter. We can accommodate remote follow-up if everything is going well and return travel is too inconvenient. We prefer to see patients in person at the first 2 visits. The first 2 follow-up visits involve a questionnaire, an exam and an x-ray.

At the 2-year follow-up we request a questionnaire, an x-ray and metal ion levels. All subsequent checks require only a questionnaire and an x-ray. Additional visits or tests are sometimes needed if problems arise. Questionnaires are available online, as are prescriptions for x-rays and physical therapists who perform the exams. We generally do not recommend seeing another doctor.

Please see the Follow-Up section of Columbia Hip Protocol for details. Typically x-rays are less expensive at independent centers rather than high-priced hospitals. Metal ion levels should be done at Quest labs.

Long-Term Precautions


This depends on your type of hip replacement. No one can ever say how long your implant will last. There are many different modes of failure. We can only quote survivorship at a certain time point after surgery. This means “ how many implants out of 100” are still functioning without having had a revision surgery at a given time point.

Overall implant survivorship is around 95% at 10 years. Few randomized controlled studies exist. Surgeon skill and experience varies tremendously. Patient populations within different studies are often not comparable. Different implant designs and brands within a class of implant type are not always equivalent. Therefore it is difficult to directly compare one hip type of hip replacement with another. There are pros and cons of different hip implants that you should consider. Results vary widely based on surgeon and implant brand.

There are basically three types of hip implants that I use. Click on the headings below to learn more about these types of implants.

Uncemented Metal on Metal Resurfacing

stable and very durable

Impact activities allowed after 6 months. No range of motion restrictions after 6 months. Extreme impact activities allowed after 1 year. No restrictions.

  • 98% survivorship at 5 years [>2000 cases], 93% survivorship of Hybrid (cemented femur/ uncemented acetabulum) at 10 years [>1000 cases].
  • Dislocation rate 0.3%, Revision for dislocation 0.1%. Adverse Wear Failures (Pseudotumors) 8/3300 = 0.2%.

Uncemented Metal-on-Metal Total Hip Replacement

stable and very durable

Impact activities allowed after 6 months. No range of motion restrictions after 6 months. Avoid extensive running.

  • 98% survivorship at 8 years [200 cases]
  • Dislocation rate 0. Revision for dislocation 0. Adverse Wear Failure (Pseudotumors) 1/200= 0.5%

Uncemented Ceramic-Polyethelene Total Hip Replacement

moderately stable and durable

No extreme flexion activities. No impact sports or heavy labor.

  • I only use these rarely in patients who desire to avoid metal bearings. Not enough cases to post personal data.
  • Dislocation rate for these 36mm bearings is estimated to be 1%. Adverse Wear Failure is not expected, long-term failures may include plastic breakage or osteolysis due to plastic wear debris.

Implants based on metal-on-plastic bearings cannot tolerate long-term impact activities. They are smaller than the natural hip bearing and therefore not as stable as anatomic sized metal-on metal bearings.

Although modern plastics are now very wear resistant, especially in combination with ceramic heads, breakage of these modern thinner more brittle plastics is a concern in patients who are too active. Therefore heavy labor and repetitive high impact activities should be avoided. Metal- on metal bearings only wear excessively when implanted incorrectly, but can tolerate high impact activities otherwise. Titanium stems of total hip replacements are more durable than plastic liners but may be subject to fatigue failure after long-term extreme impact activities.

Metal-on-metal bearings are biomechanically similar to the native hip bearing. Implant size is based on a patient’s natural anatomy. They are extremely stable and therefore no motion restrictions are required after the initial 6 months. Smaller plastic bearings are inherently biomechanically compromised. Therefore, some permanent restriction on extreme flexion activities is required. 28mm bearings have a 5% dislocation risk, 36mm bearings have a 1% dislocation risk and anatomic-sized metal bearings have a 0.3% dislocation risk.

Total hip stems are more rigid than the surrounding bone. The irritation from this causes thigh pain in about 3-5% of patients with a total hip stem. It may become limiting when patients attempt impact activities. This does not occur with resurfacing.

Although cement is still commonly used to fix implants to bone in Europe, in the US > 95% of hip replacements are of the uncemented (bone-ingrowth) type. Cement is a weak link that breaks down over time. I only use uncemented fixation in the hip.

There is no difference visible in the gait of patients with resurfacing or total hip replacement. However 4/5 laboratory gait studies show that gait is normal with resurfacing while it is not with total hip replacement. Two comparative (Barrack, Noble) survey studies have shown that a higher percentage of resurfacing patients are able to return to desired sporting activity than total hip patients.

It appears that there is no functional difference between resurfacing and total hip for the vast majority of patients who have an arthritic hip. Large metal-on-metal bearings in total hips and resurfacing provide superior stability with a small risk of adverse wear failure if the acetabular component is malpositioned. Resurfacing has the added benefits of bone preservation, thigh pain avoidance, and a better tolerance of impact activity.


The national postoperative infection rate is 1-2%. My infection rate is 0.1%. With aggressive management even these rare infections can usually be cured without loosing the implants.

Late infections that spread to the hip from other sites are rare. I estimate a lifetime risk of less than 1%. I recommend that patients with hip implants treat bacterial infections anywhere in their body promptly. Viral infections do not pose a threat. You should clean out all cuts with betadine and apply Neosporin ointment to prevent infections.

Prophylactic antibiotics are recommended for dental work and cleaning, as well as for any procedures done through a contaminated space. Your dentist or doctor performing the procedure should be notified that you have a hip implant and antibiotics should be requested. Typically a single dose prior to the procedure is all that is required. Risks of a single antibiotic dose are minimal. There is controversy about this recommendation, and no conclusive data exists. Treating late implant infections is difficult, traumatic and expensive.


Hip replacement is one of the most successful operations ever devised. It not only relieves pain and restores function; it has also been shown to extend life. Hip replacement started in the 1950’s and has made tremendous advances since that time. I now hardly do anything the same as a learned in my residency at Johns Hopkins over 25 years ago.

Minimally invasive surgery, multimodal pain management, comprehensive blood management, prevention of blood clots, uncemented technology, improved bearing surfaces and hip resurfacing are only a few of the advances that have allowed us to completely change the operation. Instead of a 2-week hospital stay and another 2 weeks in a rehab hospital we are now keeping patients overnight or even performing outpatient surgery.

Blood transfusion and infection and blood clots have an incidence far less than 1%. Dislocations are rare. Full sporting activity is possible. In the 1950s severe arthritis was a life-altering problem. Today patients can return to full normal function. I believe that we are on the threshold of lifetime implants for all patients regardless of age.

The Internet now gives patients access to extensive information, but it is sometimes difficult to know which information is reliable. Surgeons have widely varying skill sets and opinions about what is best. Don’t be satisfied with general statements of opinion. The wise patient reviews data published in writing by the surgeon he is considering. Word of mouth referrals from other patients are also very valuable. Published surgeon data can be readily accessed on the Surface Hippy website, and our own publications can be found under the Patient Education section of this website.

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