Can Revision TKA Patients Achieve Similar Clinical Functional Improvement Compared to Primaries?

The etiology of failure following primary total knee arthroplasty (TKA) leading to revision surgery are multifactorial, including infection, instability, loosening, contracture, and wear. Although the majority of patients have successful outcomes following revision TKA, postoperative complications are still increased in these patients when compared to primary patients. For this reason, there has been a continued search to identify options, including prosthesis types, to potentially improve outcomes. Therefore, the purpose of this study was to determine if the clinical results achieved following revision TKA are comparatively similar to primaries using the same implant design. Specifically, we compared (1) Knee Society Functional and Range-of-Motion Knee Scores and (2) component survivorship. This was a retrospective analysis of 100 patients undergoing revision TKA due to an aseptic etiology, who were matched to a cohort of 100 patients who underwent primaries with the same prosthesis. There were no differences in the groups with respect to age at surgery, sex, and body mass index. The mean follow-up was 57 months in the revision group (range 24-105 months) and 67 months in the primary TKA group (range 55-123 months). American Knee Society Scores (KSS) and range of motion measurements recorded preoperatively and at the most recent postoperative visit were compared between both cohorts in order to compare postoperative outcomes. A p value of 0.05 was used for significance. The average improvement between the pre- and postoperative KSS function scores in both groups was similar, with both cohorts demonstrating a 28-point improvement. At 2-year follow-up, all-cause survivorship of the aseptic revision surgeries was 87%. Patients undergoing revision TKA for aseptic loosening can potentially expect similar improvements in clinical function scores and survivorship compared to primary TKA when controlling for implant type.