Hip Resurfacing: What’s all the Buzz?
By Steven A. Myers, MD
Recently, an ad ran in our local newspaper proclaiming, “Hip replacements without replacing your hip!” While this might seem like a plausible claim in our age of amazing technological innovations such as pocket-sized computers and sophisticated cell phones, in reality, it’s not quite that simple. Hip resurfacing—the new surgical procedure touted in the advertisement—has actually been employed by orthopaedic surgeons for more than 40 years as a treatment for hip arthritis.
Early attempts were met with failure as materials used to place a cap or membrane over the painful joint surface were simply not durable enough. Various materials were explored including stainless steel, glass and even ivory—all proving unworthy to withstand the stress of daily joint use. Total hip replacement, also know as Total Hip Arthroplasty (THA), removes the top of the thigh bone (femur) and inserts a long stem into the femur with a ball attached to fit into the hip socket. Both surgical methods use a new “socket” so the difference is really just on the “ball” side. The materials used today are quite durable and offer many years of pain free function for most patients.
In comparison to a long stem implant utilized in total hip replacement, hip resurfacing involves the insertion of a protective “cap” on the top of the thigh bone (femur) where it meets the pelvis—much like a “ball and socket” joint. It preserves more of the femur, thereby making it seem “less invasive” and potentially better in the long term. In studies assessing how well patients walk after hip replacement surgery, patients undergoing hip resurfacing appeared to have more normal walking patterns than those with conventional hip replacements. However, studies reveal that both methods provide good pain relief and experience rare complications.
Through the 80s and 90s, orthopaedic surgeons honed the technique of THA, improving both the durability of the implants and the methods used to insert the devices. It is now regarded as one of the most successful surgical procedures for arthritis in the world. The improvements in manufacturing have been applied to hip resurfacing, allowing vastly enhanced standards for the production of implants that show very low levels of wear and failure rates. The matching of the surfaces of the cap and cup are now so close that in wear tests the results show even lower rates of wear than conventional total hips. These improvements are really why the orthopaedic world has seen the re-emergence of hip resurfacing, after what seemed like a dismal experience in the 60s and early 70s.
Opponents of resurfacing point to the proven track record of THA, and wonder why they should offer yet another procedure for the same problem. They also mention the risk of fracture below the cap in the femoral neck, a problem that THA avoids.
Proponents believe that the preservation of more bone in the femur will be an advantage if the device ever wears out and needs to be replaced with new parts in the future. They state that the ideal candidate is a younger arthritic patient who has strong bone, and has an expected lifespan that might be longer than the resurfacing will last. Ultimately, this is a decision that must be made by both the doctor and patient after a careful consideration of the pros and cons of all the options in treating the arthritic hip. Find a doctor who has experience with all the techniques and be prepared discuss which is best for you.