When is opening wedge osteotomy surgery indicated?
Very often the early steps for developing knee arthritis, especially in people who have been very active, has been strain on one side of the knee from, for example, the earlier removal of the shock-absorbing knee meniscus.
Initially the ligaments cope with the stress, but eventually the leg starts bowing out when bearing weight, and then the bowing may become permanent. That is when the damage triggers osteoarthritis on that side.
In selected patients, the progression of arthritis can be slowed if the forces are changed through the knee via an osteotomy.
"The objective of high tibial osteotomy (HTO) in patients with medial knee [osteoarthritis] associated with varus deformity is to transfer the weight-bearing load to the lateral compartment of the knee, thereby slowing the progression of the chondral pathology in the medial compartment....appropriate patient selection is crucial...."
"The ideal candidate for an HTO is a middle aged patient (60 to 65 years of age), with isolated medial osteoarthritis, with good range of motion and without ligamentous instability."