Unicompartmental knee replacement

Osteoarthritis can affect any or all of the three compartments of the knee joint. During the early stages of the disease a single compartment is frequently affected. Hemborg has shown that the disease usually remains confined to the initially affected compartment and White has suggested that medial component osteoarthritis does not progress while the ACL is intact. Symptoms may not be sufficiently severe to require invasive treatment but if they are it is an attractive option to merely address the damaged part of the joint leaving the ‘normal’ compartments alone. It therefore seems logical to merely treat the damaged part of the joint leaving good quality ligaments and articular cartilage in place. It also seems possible that replacing the damaged part of the joint where bone loss and collapse can be anticipated might slow down or even prevent the development of multicompartmental arthritis.