High tibial osteotomy in a lax knee: A review of current concepts.

The technique of high tibial osteotomy (HTO) was traditionally documented for symptomatic medial tibiofemoral arthrosis associated with coronal plane malalignment in a stable knee., recently, more attention has been given to the treatment of coronal malalignment in lax knees with HTO with or without ligament reconstruction. Patients with overwhelming pain, chronic ligament deficiency and coronal or sagittal deformity are generally easier to treat with HTO as compared to those who have mild pain and a proximal tibial deformity. The instability at the knee joint can be either in the coronal or sagittal plane or in both planes. Younger patients with chronic ACL deficiency, varus malalignment and advanced medial compartment arthritis, who present with pain and slight instability show satisfactory results with HTO. Double-limb weight bearing anteroposterior view radiographs are used to plot mechanical leg axis (from the centre of the femoral head to the centre of the knee), anatomical axis (a line from the centre of the piriformis fossa to the centre of the knee joint and a line through the long axis of tibia) and weight bearing axis (line drawn from the centre of the femoral head to the centre of the ankle joint) and are used to plan HTO. A 3-dimensional pre-operative plan using CT and MRI is recently studied. The decision to perform HTO alone or in combination with ligament reconstruction involves consideration of patient demographics, symptoms and ligaments involved. The most commonly used surgical techniques for high tibial osteotomy include lateral close wedge osteotomy, medial open wedge osteotomy and dome osteotomy. The post-operative rehabilitation depends on the rigidity of fixation.