Results of total knee arthroplasty with NexGen LPS-Flex for osteoarthritis in the valgus knee: a study of 26 patients followed for a minimum of 2 years.

Abstract

The present study aimed to examine the results of total knee arthroplasty (TKA) with the NexGen Legacy posterior-stabilized (LPS)-Flex system for osteoarthritis in the valgus knee. Between 2003 and 2011, 27 valgus knees in 26 patients who underwent TKA with the NexGen LPS-Flex implant were clinically and radiologically evaluated after a minimum follow-up of 2 years. The original diagnosis was osteoarthritis. Knee Society Knee Score (KSKS), Knee Society Function Score (KSFS), maximum flexion angle, maximum extension angle, and radiological femorotibial angle (FTA) were evaluated pre- and postoperatively. The mean KSKS improved from 42.6 before surgery to 82.2 by the final follow-up (p < 0.01), and the mean KSFS improved from 41.1 to 80.9 (p < 0.01). The mean maximum flexion angle changed from 109.1° to 117.3° (no statistical significance) and the maximum extension angle improved from -9.7° to -3.6° (p < 0.05) postoperatively. The postoperative radiological FTA was 172.4°, which was closer to a neutral angle (174°) than the preoperative FTA (166.4°) (p < 0.01). None of the patients had undergone revision surgery by the final follow-up. As a conclusion, TKA with the NexGen LPS-Flex implant for osteoarthritis in the valgus knee resulted in satisfactory improvement regarding objective outcomes, although a longer term follow-up with a greater number of cases is necessary to verify these results.