Abstract
The biomechanical rationale for osteotomy and the pathogenesis of degenerative arthrosis accompanying malalignment has been delineated well. Malalignment of the limb results in added stress on damaged articular cartilage and causes further loss of articular cartilage that subsequently exacerbates the limb malalignment. A downward spiral of progressive deformity and additional loss of articular cartilage occurs over time. Osteotomy can be used to realign the limb, reduce stress on the articular cartilage at risk and share the load with the opposite compartment of the knee. In appropriately selected patients osteotomy is a reliable operation to improve pain and function. Over the past two decades osteotomy has been viewed largely as a temporising measure to buy time for patients before they ultimately have a total knee arthroplasty. In this role, osteotomy has largely been accepted as successful. Substantial improvements in pain and function have been documented and seem to hold up well over a 7 to 10 year period after the osteotomy. Medial opening wedge osteotomy has recently gained in popularity in the United States after a long period of use in Europe. Potential advantages of the medial opening wedge technique include the ability to easily adjust the degree of correction intra-operatively, the ability to correct deformities in the sagittal plane as well as the coronal plane, the need to make only one bone cut, and avoiding the tibiofibular joint. The downsides of the opening wedge technique include the need for bone graft to fill the created defect, a potentially higher rate of non-union or delayed union, and a longer period of restricted weight bearing after the procedure.
