Background: There is limited population-based literature on rates and risk factors for revision following primary total hip replacement.
Methods: We performed a retrospective cohort study of Medicare beneficiaries who had elective total hip replacement for osteoarthritis between July 1, 1995, and June 30, 1996. Patients were followed with use of Medicare claims through 2008. The primary end point was revision total hip replacement as indicated by hospital discharge codes according to the International Classification of Diseases, Ninth Revision. We used the Kaplan-Meier method to plot the risks of revision and of death over a twelve-year follow-up period. We used Cox proportional hazard regression models to identify preoperative risk factors for revision of primary total hip replacement. We conducted sensitivity analyses to account for competing risks of major comorbid conditions.
Results: The risk of revision total hip replacement for patients remaining alive was approximately 2% per year for the first eighteen months and then 1% per year for the remainder of the follow-up period. The absolute risk of death over the twelve-year follow-up period exceeded the risk of revision total hip replacement by a factor of ten (59% vs. 5.7%) in patients older than seventy-five years at the time of primary total hip replacement and by a factor of three (29% vs. 9.4%) in patients sixty-five to seventy-five years old at the time of surgery. In multivariate Cox proportional hazard models, the relative risk of revision was higher in men than in women (hazard ratio [HR], 1.23; 95% confidence interval [95% CI], 1.15, 1.31) and in patients sixty-five to seventy-five years of age at the time of primary total hip replacement than in those over seventy-five years (HR, 1.47; 95% CI, 1.37, 1.58). Patients of surgeons who performed fewer than six total hip replacements annually in the Medicare population had a higher risk of revision than those whose surgeons performed more than twelve per year (HR, 1.21; 95% CI, 1.12, 1.32).
Conclusions: Efforts to reduce the number of revision hip arthroplasties should be targeted at revisions occurring in the first eighteen months following the index arthroplasty, when revision risk is higher, and at younger patients, who are more likely to survive long enough to require revision.
Level of Evidence: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.
Investigation performed at the Orthopedic and Arthritis Center for Outcomes Research, Department of Orthopedic Surgery, Brigham and Women’s Hospital, Boston; the Department of Orthopedic Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts; the Department of Medicine, University of North Carolina, Chapel Hill, North Carolina; and the Department of Orthopedic Surgery, University Health Network, University of Toronto, Toronto, Ontario, Canada
This article was chosen to appear electronically on September 12, 2012, in advance of publication in a regularly scheduled issue.
A commentary by Kevin J. Bozic, MD, MBA, and Steven M. Kurtz, PhD, is linked to the online version of this article at jbjs.org.
Disclosure: One or more of the authors received payments or services, either directly or indirectly (i.e., via his or her institution), from a third party in support of an aspect of this work. In addition, one or more of the authors, or his or her institution, has had a financial relationship, in the thirty-six months prior to submission of this work, with an entity in the biomedical arena that could be perceived to influence or have the potential to influence what is written in this work. No author has had any other relationships, or has engaged in any other activities, that could be perceived to influence or have the potential to influence what is written in this work. The complete Disclosures of Potential Conflicts of Interest submitted by authors are always provided with the online version of the article.
- Copyright © 2012 by The Journal of Bone and Joint Surgery, Incorporated
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