Revision Total Knee Arthroplasty Using a Constrained Condylar Knee Prosthesis Combined with a Posterior Stabilized...

Intraoperative assessment of valgus-varus stability is crucial for choosing articular surfaces with different levels of constraint. Legacy constrained condylar knee (CCK) prostheses are readily available to assemble and use with a CCK articular surface or a posterior stabilized (PS) articular surface in revision knee arthroplasty surgeries. We wanted to validate outcomes of revision total knee arthroplasty (TKA) using legacy CCK prostheses combined with a PS articular surface. Thirty-seven patients were enrolled and followed up for more than 2 years. Range of motion (ROM), the Knee Society score (KSS), the Knee Society functional score (KSS-F), and the Western Ontario and McMaster Universities Arthritis Index (WOMAC) were used to evaluate outcomes. Follow-up was a mean of 86.5 months (range: 28-152 months). The mean age of the participants was 69.8 years (range: 31-86 years). The mean ROM was 110.5 degrees, the KSS was 86.2 points, the KSS-F was 68.3 points, and the WOMAC score was 22.6 points. Seven participants had implant failures: five because of delayed infections and two because of posterior dislocations. In conclusion, revision TKA using a CCK prosthesis combined with a PS articular surface might provide satisfactory mid-term outcomes. Delayed infection was the most common cause of implant failure. Dislocation might occur in middle-old or older patients despite careful intraoperative examination of valgus-varus stability, extension-flexion gap balancing, and signs of recurvatum.