OBJECTIVE Restoration of mechanical axis of the leg. METHODS Osteoarthritis of medial knee compartment. Overload of medial compartment. Genu varum. METHODS Smoker. Vascular impairment. Poor soft-tissue envelope. METHODS Straight 12-cm midline incision starting distal to the tibial tubercle medially and continuing parallel to the tibial crest. Oblique osteotomy at 60 degrees distal-medial to proximal-lateral preserving the lateral cortex. Osteotomy wedged open and alignment checked with diathermy cord. Two tricortical bone blocks harvested from ipsilateral iliac crest or bone substitute wedges placed in osteotomy. Stabilization with contoured T-plate. Closure over drain. RESULTS 44 patients (32 men, twelve women, average age 48 years) with 45 osteotomies. Follow-up 30 months (7-74 months). All osteotomies consolidated. 90% patients had excellent results according to the HSS (Hospital for Special Surgery) Knee Score. In 77% the femorotibial angle was corrected to 5-12 degrees . Patients regained their preoperative range of motion. There were no major complications.