“Sobering” was the word used by a co-author on a recent study showing that we haven’t really moved the needle on total knee arthroplasty (TKA) revisions after two decades.
The study, “Why do Revision Total Knee Arthroplasties Fail? A Single-Center Review of 1,632 Revision Total Knees Comparing Historic and Modern Cohorts,” appears in the May 27, 2020 edition of the Journal of Arthroplasty.
Bryan D. Springer, M.D., fellowship director at the OrthoCarolina Hip and Knee Center and professor of orthopedics at the Atrium Musculoskeletal Institute in Charlotte, North Carolina, explained a little bit of the history behind this important study to OTW, “A decade ago, we published the exact same study. The purpose at that time was to take a critical look at our practice of revision total knee arthroplasty, determine where most of our failures were occurring, and set a road map to see if we could identify areas where improvements could be made.”
“The impetus for this study was to essentially repeat that work a decade later and determine if any major improvements have been made. I do not think anyone would argue that implants are better, polyethylene is better, surgical techniques and patient outcomes are better than what they were a decade ago. The major question is, ‘When we critically look at our failures have the reasons for failures changed over time?’”
And what is NOT improving, says Dr. Springer? Infection.
“The results of the study were interesting and somewhat sobering. The interesting part was the overall failure rates and reason for revisions did not changed substantially over the last two decades. Certainly, I think we are getting better with mechanical failures, problems with polyethylene wear and osteolysis.”
“However, it is the biologic problem of infection that persists. It continues to be a major plague for surgeons and patients alike. Despite our efforts it continues to be a major reason for failure. In addition, when patients have a prior history of failure for septic reasons the recurrence rate is extraordinarily high.”
Patient selection and perioperative optimization are key.
“This study helped us to identify patients that are at high risk for failure of their revision. Namely, this is younger males. However, a history of infection dramatically alters outcomes. What this really means is that we need to continue to be vigilant about proper patient selection and perioperative optimization to lower the initial risk for the development of periprosthetic joint infection. Once infection occurs, however, we need to continue to innovate and determine best practices as well as now full ways to deal with the problem of periprosthetic joint infection.”
“We will get there. I do think we are making improvements. It is important that all centers continue to critically evaluate failures not only in revision total knee but also in primary total knee so that we can determine where to best focus our efforts clinically as well as through research.”
Patients who were enrolled in the study had an average age 65.1 and received follow-up care for an average of 61.4 months after surgery. The overall failure rate of patients in the study was 22.8%, with no significant differences between the historic and modern cohort (25.1% vs 22.0%, p=0.19). The leading cause for failure was infection in 38.5% of failures. The next most common causes for failure were aseptic loosening (20.9%) and instability (14.2%). Failure rate among revision TKAs for infection was 33%, with 67.2% failing due to repeat infection. Multivariate analysis found that septic index revision (OR 1.91, 95%CI 1.47-2.48), male gender (OR 1.41, 95%CI 1.11-1.78), and age less than 65 (OR 1.56, 95%CI 1.23-1.97) were independent risk factors for failure.
