Artificial hips and knees last up to 25 years

Reference

Evans JT, Evans JP, Walker RW, Blom AW, Whitehouse MR, Sayers A. How long does a hip replacement last? A systematic review and meta-analysis of case series and national registry reports with more than 15 years of follow-up. Lancet 2019;393(10172):647-654. Evans JT, Walker RW, Evans JP, Blom AW, Sayers A, Whitehouse MR. How long does a knee replacement last? A systematic review and meta-analysis of case series and national registry reports with more than 15 years of follow-up. Lancet 2019;393(10172):655-663.

Synopsis

These researchers searched 2 databases and the bibliographies of included papers and review articles for pretty much any kind of study of hip or knee replacement surgery that reported at least 15 years of follow-up data. In addition, they also collected data from the national registries of Australia, Denmark, Finland, New Zealand, Norway, and Sweden. Those registries have all been around since 1975. The authors excluded papers not published in English. Although they did not clearly describe the process for selecting papers, the authors assessed the quality of included studies using a system adapted for the anticipated high rate of loss to follow-up. Ultimately, they included 44 hip replacement papers (13,212 hips) and 30 knee replacement papers (7232 knees). Additionally, the researchers had data from multiple national registry reports with more than 200,000 hip replacements and nearly 300,000 knee replacements. Among the studies of patients with knee replacements, none reported 25-year outcomes for patients with total knee replacements and only one reported 25-year outcomes for unicompartmental replacements. The average age of patients in the studies reporting hip replacement outcomes was younger than those in the national registries (58 years vs 68 years), but the average age of those undergoing knee replacement was comparable (~ 68 years). For hip replacements, the patients in the published studies fared better than those in the registries—78% and 58%, respectively, lasted 25 years. Among total knee replacements, the registry data indicate 82% survive 25 years. For unicompartmental replacements, the sole publication reported 72% last 25 years while the registry data showed 70% last that long. Because the authors excluded data with short-term follow-up, we have no information about early failures, and can only say that if the joint lasts 15 years, it is likely to last 25 years.