Good functional results of distal femoral opening-wedge osteotomy of knees with lateral osteoarthritis

To evaluate the time-dependent functional outcome of patients with lateral knee osteoarthritis with increased valgus treated with lateral opening-wedge osteotomy to shift the load from the lateral to the medial compartment of the knee.

Twenty-four consecutive patients with lateral knee osteoarthritis were treated with distal femoral opening-wedge varus osteotomy stabilized with the Puddu plate and bone transplantation. The mean age of the patients was 48 years (CI 40.3–55.7, range 31–62). The patients were evaluated by the Knee Injury and Osteoarthritis Outcome Score (KOOS) preoperatively and at 3 and 6 months, 1, 2, 5 and 10 years post-operatively. The knee osteoarthritis was graded according to the Kellgren–Lawrence radiological scoring system. The mean follow-up time was 7.9 years (CI 6.8–9.0, range 4.0–10.2).

The mean angular correction measured on pre- and post-operative radiographs was 9.6° (CI 7.7°–11.5°, range 4°–20°). All osteotomies healed. KOOS increased significantly during the first year by 28–122 % beyond the preoperative values for all the five subscores. This improvement remained at 10-year follow-up for those with surviving osteotomy. Six knees were converted to total knee arthroplasty (TKA) mean 6.4 years (CI 3.3–9.6, range 4.0–11.8) post-operatively. The osteotomy survival rate at 5 years was 88 % and at 10 years 74 %. The preoperative osteoarthritic grade did not increase significantly during the follow-up period, but was significantly correlated (r = −0.49), P = 0.019 to the KOOS subscore symptoms at the 2-year follow-up.

Distal femoral opening-wedge osteotomy for lateral knee osteoarthritis resulted in good functional recovery after 1 year and favourable midterm results. It may be a good treatment option for middle-aged patients with valgus knees and lateral osteoarthritis in order to prevent or postpone TKA.

IV.