Short-to-Midterm Outcomes of Revision Total Knee Arthroplasty Patients With a Total Stabilizer Knee System

Abstract

Background: Revision total knee arthroplasty (TKA) can often be challenging. The use of a new revision system may aid in providing better stability, improved function, fit, and implant longevity. Therefore, we assessed: (1) survivorship, (2) clinical outcomes, (3) postoperative complications, and (4) radiographic outcomes of patients who underwent revision TKA using this system.

Methods: Patients from 2 hospitals who underwent revision TKA using a newer generation revision knee system between June 2008 and December 2013 for component instability or aseptic loosening were included. There were 93 patients, who had a mean age of 65 years (range, 41-84 years), and a mean follow-up of 4 years (range, 2-7 years). Survivorship was assessed using Kaplan-Meier analysis. Radiographic analysis was performed using the new Knee Society Roentgenographic Evaluation and Scoring System.

Results: Aseptic survivorship was 96% (95% confidence interval, 6.6-7.3), and all-cause survivorship was 94% (95% confidence interval, 6.4-7.2). There were 2 infections and 4 aseptic loosening cases. The mean Knee Society score was 86 points (range, 38-100 points) and the mean functional Knee Society score was 52 points (range, 15-90 points) at final follow-up. The mean postoperative extension and flexion were 2° (range, 0°-20°) and 106° (range, 20°-130°), respectively. There were 3 medical and 11 surgical complications. Excluding the aseptic and septic failures, there were no progressive radiolucencies or osteolysis at final follow-up.

Conclusion: At up to 7-year follow-up, this new revision system demonstrated excellent survivorship and good functional outcomes. Future studies should be prospective, comparative, and include larger cohorts for further assessment of this device.

Keywords: implant; midterm outcomes; outcomes; revision total knee arthroplasty; survivorship; total stabilizer knee system.