A study suggests that cholesterol-lowering drugs known as statins may help hip replacements last longer and could ward off complications and the need for follow-up surgeries.
Most joint replacements go smoothly, and 90 percent of people who get new hips can expect their implants to last 10 to 20 years without problems.
But in some cases, infections, dislocations and fractures may cause a new hip to become dislodged or loosened. In those cases, a second surgery, called a revision surgery, is needed to replace the implant.
Using data in the Danish Hip Arthroplasty Registry, researchers studied the medical histories of 2,349 patients who needed a revision surgery for a hip replacement over a 10-year period and compared them with hip replacement patients of the same age and sex who had not needed a revision.
Overall, any patient in the registry had an 8.9 percent risk of needing a fix or a replacement for their new joint, but those who took statin medications saw a 66 percent reduction in that risk, giving them a risk of revision of 5.9 percent.
“The big news is that we found a substantially reduced risk of revision after hip replacement in users of statins. This has not previously been examined in the scientific literature; neither in clinical studies nor in population-based studies,” says Theis Thillemann, MD, PhD, the study’s author and a fellow in the Department of Orthopaedic Surgery at Aarhus University Hospital in Denmark.
The study was published in the May 2010 issue of The Journal of Bone and Joint Surgery.
While researchers found this association, they can’t say for sure that statins are the reason for the reduced risk.
That’s because people who take statins tend to be more concerned and conscientious about their health and may be taking other steps that reduce their risk of infections or fractures that can’t be measured by the study.
But other studies have shown that statins have important effects on bone that may explain this finding. They increase bone formation, which may help connect the implant to the bone, and they have been shown to reduce inflammation, which may keep implants from loosening and reduces infections around the implant.
“For now our findings are very positive for patients who are receiving statins due to other diseases,” Dr. Thillemann says. “However, further research is necessary before statins can be recommended for otherwise healthy patients undergoing hip replacement surgery.”
But he adds that many patients undergoing hip replacement surgery will already be on statins due to cardiovascular disease or diabetes, and for these patients, it is important to know that these medications may benefit their new joints.
Benjamin Bengs, MD, an orthopedic surgeon at the UCLA Medical Center, in Los Angeles, says this study shows an interesting association between statins and better outcomes after hip replacements.
But he says it’s not enough to make him change his practice because, as the study authors point out, they didn’t show statins directly cause this.
“Statins are systemic medication, and it may turn out there are many intended and unintended effects. Some may be potentially beneficial and some may be potentially detrimental,” Dr. Bengs says. “This study may have found a potential benefit on musculoskeletal health. But the other interpretation is the statin use by patients may be a proxy for a healthier way of life. These patients may be more compliant, more lucid, more invested in their health, less risk taking, less smoking. It may very well be just a proxy marker for healthier living.”