Fig. 1
From: Results of total knee arthroplasty for painless, stiff knees
A 44-year-old female patient who had bilateral knee pain due to rheumatoid arthritis. The right knee showed 15º range of motion (ROM) (range; 30–45º) and the left knee was spontaneously ankylosed in 40º of flexion. In the right knee, a PS type (Nexgen LPS) prosthesis was used, and in the left knee, a valgus-varus constrained (VVC) type (Nexgen LCCK) prosthesis was used. The right-knee arc of motion improved from 15 to 85º (range; 0–85º) and the left-knee arc of motion improved from 0 to 85º (range; 0–85º). No complications were noticed during the 16-year follow-up. The left knee (complete ankylosis) was included in this study