Long-term survival in total knee arthroplasty (TKA) depends on multiple factors, including restoration of mechanical alignment and obtaining optimal ligament balance. The aim of this study was to document the results of single-stage TKA combined with high tibial osteotomy for managing femorotibial arthrosis with significant frontal-plane deformity.
Patients with osteoarthritis of the knee and extra-articular deformity in > 10° and operated between 1997 and 2001 were reviewed retrospectively. In each case, a high tibial osteotomy combined with a posterior stabilised TKA was performed. Patients were assessed using the Knee Society Score (KSS). The femorotibial mechanical angle was measured on radiographs pre- and postoperatively and at the most recent follow-up.
Fifteen knees in 12 patients were included in the study. Mean age was 68.2; average follow-up was 78 months (22.1-145.9). The KSS improved significantly from 47.1 (28-58) to 60.7 (40-94) points (p < 0.05), with the KSS functional score improving from 45.1 (21-69) to 72.3 (30-100) points (p < 0.05). The femorotibial mechanical axis (mFTA) also improved significantly, from 161.7° (156-170°) preoperatively to 175.8° (170-182°) postoperatively (p = 0.002). There were four intra-operative tibial plateau fractures and two revisions for nonunion at the osteotomy site. Survival at 22 months was 86.7% [95% confidence interval (CI) 64.5-99.5%].
The combination of a TKA and high tibial osteotomy is a valid option for treating arthrosis with large extra-articular frontal-plane deformity. Rigid fixation of the osteotomy is essential.