Hip Replacement Revision Rates Highest in First 18 Months

Lara C. Pullen, PhD

October 31, 2012

Hip arthroplasty revision is highest in the first 18 months after the index arthroplasty. Revision risk is also higher in younger patients who are more likely to survive to require revision.

Jeffrey N. Katz, MD, from Brigham and Women's Hospital in Boston, Massachusetts, and colleagues published the results of their retrospective cohort study in the October 17 issue of the Journal of Bone and Joint Surgery. The authors examined a cohort of 51,347 Medicare beneficiaries who, between July 1995 and June 1996, received elective primary total hip replacement for osteoarthritis.

The authors suggest that surgeon practices influence early failures. In contrast, implant and patient characteristics influence later failures. The authors found an increased risk for revision associated with younger age and with male sex. Specifically, the hazard ratio (HR) of the relative risk for revision in men compared with women was 1.23 (95% confidence interval [CI], 1.15 - 1.31), and patients aged 65 to 75 years at the time of primary total hip replacement were more likely than those older than 75 years to have primary hip replacement (HR, 1.47; 95% CI, 1.37 - 1.58). The risk for revision total hip replacement was approximately 2% per year for the first 18 months and then 1% per year for the remainder of the follow-up period. The absolute risk of death during the 12-year follow-up period exceeded the risk for revision total hip replacement by a factor of 10 (59% vs 5.7%) in patients older than 75 years at the time of primary total hip replacement and by a factor of 3 (29% vs 9.4%) in patients aged 65 to 75 years at the time of surgery.

The study was limited by the fact that the Medicare coding does not specify right- or left-sided procedures and therefore does not distinguish between a revision and a second primary total hip replacement. In addition, some patients may have received a recommendation for revision and declined the surgery.

The authors conclude by suggesting that future studies identify the predictors of revision in younger patients.

American Joint Replacement Registry

Joshua Jacobs, MD, from Rush University Medical Center in Chicago, Illinois, and the first vice president of the American Academy of Orthopedic Surgeons, spoke with Medscape Medical News about the study by telephone. He explained that although hip replacement is an extremely successful procedure, revision is also important: "One of the more common reasons for failure is wear or tear over time, especially for younger patients."

In Dr. Jacobs' experience, approximately 15% of hip replacements are revision procedures. Revision hip surgeries are not only difficult for the patient but also have a big effect on our health system. Within the first 18 months, the main causes of hip revision include infection and hip dislocation or instability.

The authors note that the surgeries described in this study were performed in the 1990s, before the recent advances in implant technology and surgical technique. Dr. Jacobs agreed, explaining that "hip replacement has changed a lot in the 16 years since that time." He wondered whether the data in the article are reflective of the surgeries being performed now.

Dr. Jacobs elaborated that a US joint replacement registry would be able to provide helpful, real-time data. Other countries such as Australia, the United Kingdom, and Sweden have successfully implemented a joint replacement registry, and Sweden was able to use their registry to cut their revision rate.

An American Joint Replacement Registry has been created. Its goal is to have participation by 90% of the hospitals in the United States. Dr. Jacobs pointed out, however, that the creation of such a registry in the United States is more difficult than the creation of a registry in other countries, as the United States not only has many patients but also has a more fragmented healthcare system.

Dr. Katz has disclosed no relevant financial relationships. One author serves as a consultant for DePuy Orthopedics. Another author owns stocks or stock options with Pfizer and Johnson & Johnson. Full conflict-of-interest information is available on the journal's Web site. Dr. Jacobs receives research funding from Zimmer, Medtronic, NuVasive, and SpinalMotion and owns stock options in Implant Protection.

J Bone Joint Surg. 2012;94:1825-1832. Abstract