A case of high tibial osteotomy in a patient with psoriatic arthritis.

Traditionally, patients with rheumatic diseases, such as rheumatoid arthritis (RA), were considered off-limits for joint-sparing surgery. In the present study, we report bilateral knee joints of psoriatic arthritis coexisting with osteoarthritis, with good, albeit short-term, results. 62-year-old woman was treated for psoriatic arthritis with a biologic (adalimumab). The Disease Activity in Psoriatic Arthritis index was 7.24, indicating low disease activity. She had been suffering from bilateral knee pain for some time and was treated conservatively by her local doctor, but the pain persisted, and she came to visit us. At the initial visit, tenderness in the medial joint line of both knees and hydrarthrosis in the right knee were observed. Radiographs at the time of the initial examination showed medial type osteoarthritis (Kellgren-Lawrence classification IV) in both knees. First, interlocking closed wedge high tibial osteotomy (CWHTO) was performed on the right knee. This was followed 1 year later by right knee implant removal and interlocking CWHTO on the left knee, and implant removal on the left knee 1 year after that. The joint range of motion improved in both knees preoperatively and postoperatively, and the change in the Knee Injury and Osteoarthritis Outcome Score total from preoperative to 1 year postoperatively was from 26.0 to 59.4 points for the right knee and from 48.6 points to 70.5 points for the left knee, with improvement in both knees. Considering the patient's background, we considered high tibial osteotomy if the disease activity was controlled. However, if the disease worsens in the future, joint destruction may occur, so careful follow-up is necessary.