We reviewed thirty-two patients (38 knees) who had undergone high tibial osteotomy (interlocking wedge osteotomy). Thirty-eight osteoarthritic knees were evaluated by arthroscopy, before osteotomy and an average of 18.8 months after osteotomy. We graded the arthroscopic findings of the articular surface and the meniscus according to Fujisawa's classification. We observed fibrous tissue growing over the ulcerated area in the medial compartment. In most patients the articular surface of the lateral compartment was unchanged but fibrillation was seen a quarter cases. Fibrillation was also seen on the lateral meniscus in a quarter of cases, but they had no symptoms.
