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Comparing hip resurfacing to standard total hip replacement
Hip Resurfacing is a type of Total Hip Replacement (THR) that allows full athletic function and lasts much longer than a standard stemmed THR. No prosthetic hip totally recreates a normal hip, but hip resurfacing comes much closer.
Most people with severe hip arthritis are very satisfied with total hip replacement (THR); older folks who are happy to walk pain-free and golf are usually satisfied. However, there are several reasons many people still would prefer a better option:
- Many younger people want a chance to return to regular vigorous exercise, impact sports, or heavy physical work.
- Some people just don’t want so much of their own bone removed and a large “spike” driven into their femur.
- Everyone wants the longest-lasting artificial hip.
Unfortunately, most joint replacement specialists who perform THR, never inform patients that there is another option – Hip resurfacing arthroplasty (HRA). Most patients with a severely arthritic hip are just told that they need a THR. If they know enough to inquire about hip resurfacing, they are usually provided with incorrect or outdated information to discourage this option. This website provides extensive explanations and, most importantly, data to counter this misinformation.
Why is hip resurfacing superior?
- Better Function - Full athletics and heavy physical work
- More Durable - 99% 17-year implant survivorship
- Superior Stability - 10-fold lower dislocation risk
- Improved life expectancy - at least 25% better by 10 years
- Less chance of wear/corrosion failures - None since 2009, in over 5000 cases
- Bone Preservation - Only 4mm of bone removal from either side of the joint
- Lower fracture rate- 0.2% in first year and 1% by 17 years. compared to 1-2 % in 1 year and 7.7% in 20 years (Mayo clinic)
Great advances have been made in hip resurfacing since I started in 1999. Most joint replacement surgeons have not kept up with the data. When comparing THR to hip resurfacing there are many criteria that can be used to evaluate the two operations.
Hip resurfacing comes out looking better by ALL criteria. Hip resurfacing gives a better functioning hip, a more stable hip, it preserves bone, has a lower wear/corrosion rate, and far better durability. The long-term mortality rate of patients with hip resurfacing is more than 25% lower than similar patients with THR.
What then is the advantage of a THR?
It is the traditional way that a severely arthritic hip is repaired, and most orthopedic surgeons are trained to perform it with good outcomes. Hip resurfacing is a much more complex operation that most orthopedic surgeons do not have the necessary skill to perform. Many have tried and failed to achieve similar outcomes as they can with THR and have therefore reverted back to THR. Others are intimidated to try to learn this more complicated operation or because of the climate of fear created by "thought leaders" in THR around the subject of metal ions.
These opponents to hip resurfacing claim that hip resurfacing has a high rate of failure due to adverse wear and that THR is functionally equivalent. They are mistaken on both counts. All surgeons have opinions, and the majority are against hip resurfacing; on this website, I counter these opinions with facts. You get to be the judge.
How is hip resurfacing different than THR?
Hip resurfacing replaces only a thin layer of bone on either side of the joint with metal creating new artificial cartilage layers. The central problem we are correcting when a patient has severe arthritis is surface cartilage loss. In hip resurfacing, only 4mm of bone is removed from either side of the joint to make room for the two new thin artificial surfaces. In standard THR, much more bone is removed and replaced by metal and other materials, creating an artificial hip that is less like the natural hip.
In both THR and hip resurfacing, the same amount of cartilage and bone is removed from the socket (acetabulum) side, the difference is on the femur, where resurfacing requires replacing only a thin layer of the femoral head. With THR the whole head is amputated, and a stem is driven deep into the femoral shaft, this stem then supports a smaller-than-natural artificial head.
Why is so much bone removed in a THR? Traditionally the materials used to line the socket are quite thick. After removing only 4mm of bone, a socket component of 10-12 mm thickness is placed. The diameter of the natural socket is therefore reduced considerably in the new artificial socket. This requires a smaller head size.
It is not possible to shave the femoral head (ball) enough to make room for a smaller ball without cutting into the femoral neck. Therefore, the head is amputated, and a stem is fixed into the femoral shaft. This allows a smaller artificial head to attach to this metal stem. This smaller ball then fits into the smaller socket.
In a hip resurfacing, the same 4mm of socket bone is removed as in a THR, but it is replaced with a thinner all-metal 4mm socket piece. The thickness of the socket implant matches the thickness of the bone removed; thus, the natural hip socket size is retained. On the femoral ball, a 4mm surface is also removed and replaced with 4mm of metal. The result is an artificial hip that more closely simulates the natural hip. Mimicking the biomechanics of the natural hip joint of course leads to a more normal feeling and functioning joint.