Clinical results of total knee arthroplasty in patients with severe varus deformity

Total knee arthroplasty(TKA) for patients with severe varus deformity has become common operation in Japan because of the rapid aging of the population. Treatment of severe malalignment, instability and bone defects is important. Here we report the clinical results of total knee arthroplasty for 23 knees with severe varus deformity. We defined a severe varus knee femorotibial angle(FTA) as one exceeding 195 degrees. The average observation period was 64 months. Autologous bone graft was performed for 3 knees and augmentation and long tibia stem was used for 3 knees. We used SF-36 for clinical evaluation. Image assessment was based on the standing HKA(Hip-Knee-Ankle)angle, and the Knee Society TKA roentgenographic evaluation and scoring system. The mean SF-36 score improved from 47.6 points to 63.7 points after TKA. The standing mean HKA angle was 204°(range 197° to 215°) before surgery and was corrected to 185°(range 176° to 195°). The post-operative standing HKA angle was classified as HKA>184°, 184°>HKA>177°, HKA 184° group. Our 23 knees achieved good results, and careful postoperative observation is still necessary especially in the vgarus group.