Influence of the cause of the revision on the outcome after revision knee arthroplasty with condylar constrained implant.

INTRODUCTION

Revision total knee arthroplasty (TKA) is a common procedure with varying results depending on the cause. Our objective was to compare the clinical and radiological outcomes in patients undergoing aseptic revision versus revision due to prosthetic infection.

MATERIAL AND METHODS

The study included 41 patients who underwent TKA revision with the same varus-valgus constrained implant. In all cases a clinical evaluation was performed including pain, range of motion (ROM), Knee Society Score (KSS), complications, as well as radiological study. A comparative analysis was performed on the pre- and postoperative results between septic and aseptic groups. The mean follow-up was 6 years.

RESULTS

ROM had a mean increase of 17 degrees (p<.01). KSS and functional KSS improved significantly postoperatively. In the radiological study, joint interline and limb alignment were restored in all cases. Radiolucencies were found in 36.5% of cases; however they were unrelated to the appearance of loosening of the implant. There were complications in 29.2% of cases, mostly related to the surgical wound. Mobility, KSS, KSS functional and satisfaction at follow-up were better in the septic group. Implant survival was 95% at follow-up.

CONCLUSION

Revision arthroplasty with constrained varus-valgus implant is safe, and has successful mid-term results despite the cause of the replacement procedure.