The authors have reviewed 250 cases of upper tibial osteotomy for varus deformity of the knee with degenerative arthritis of the medial compartment. Most of the osteotomies (136) were closing osteotomies, the remainder being opening osteotomies using a bone graft. Closing osteotomy is recommended together with an arthrolysis of the upper tibio-fibular joint instead of a fibular osteotomy. Hyper-correction appeared to be beneficial in cases with lateral ligament laxity. The authors do not recommend intra-articular cartilage shaving or meniscectomy. They advocate surgical release of the patella by division of the lateral patellar retinacula or by anterior displacement of the tibial tuberosity.