Ashley William Blom, MD, PhD, professor of orthopedic surgery, University of Bristol School of Clinical Sciences, Bristol, UK, and lead author of a study published in The Lancet.
A few years back, many folks with hurting hips were happy to learn that a newer bone-preserving procedure called hip resurfacing could spare them from the more drastic hip replacement.
But: A huge study has now shown that the newer procedure is more likely to lead to problems than the traditional total hip replacement.
Ashley William Blom, MD, lead author of the new study, weighed in on the results and what they mean for patients contemplating hip surgery.
In a traditional hip replacement, the femoral head (the bony ball at the top of the thighbone that fits into the hip socket) and femoral neck (the angled piece of bone connecting the head to the main shaft of the thighbone) are completely removed, along with the damaged portion of the hip socket. They are replaced with a ceramic, metal or plastic ball-and-socket mechanism attached to a long stem that is inserted into the thighbone shaft.
In contrast, with hip resurfacing, only superficial layers of the femoral head are removed. The area is then covered with a metal-on-metal cap-and-bearing assembly. Since little bone is removed and no long stem goes into the shaft, resurfacing seems relatively noninvasive. However, resurfacing does require a large incision that cuts and stretches a significant amount of muscle tissue. Resurfacing generally is considered most appropriate for younger, healthier patients who would be expected to recover fairly easily, as some proponents claim it gives better function in more physically demanding patients.
To compare the success rates of these two procedures, Dr. Blom and his colleagues examined data on 434,560 hip operations performed between 2003 and 2011. They analyzed which surgeries ultimately failed and needed to be redone within seven years of the original procedure. Reasons for such failure included unexplained long-term pain, fracture of the femoral neck and/or a negative reaction of the soft tissue to the metal implant.
Almost across the board, resurfacing procedures were more likely to fail—and to do so more quickly—than total replacements.
Among men, the smaller the femoral head, the higher the chance that the resurfacing implant would fail. Exception: Men with large femoral heads (generally men with large frames) had fairly comparable success rates with resurfacing and with replacement, so Dr. Blom noted that there still may be a place for hip resurfacing among this select group. However, fewer than one-fourth of study participants fell into that category.
Women fared much worse, suffering resurfacing failure rates that were “unacceptably high,” Dr. Blom said—up to five times higher than with replacement. Since problems were common even among women with relatively large femoral heads, he now recommends against hip resurfacing for women.
Bottom line: Despite marketing campaigns that use terms like “young and active” to sell the public on the hip-resurfacing trend, it seems as though this is one case in which the old way is better than the new way.
What if you already had hip resurfacing? Dr. Blom said to alert your doctor right away if you develop pain in the hip or leg or difficulty walking, which might signal a fracture or other problem at the surgical site. He also advised seeing your doctor annually—even if you feel fine—so he or she can check for problems that you may not necessarily see or feel. For example, a doctor can tell you definitively whether you have a fracture or a negative reaction to the metal implant.