Knee replacement (partial) surgery

Partial knee replacement, also known as unicompartmental knee replacement, may be suitable for patients suffering from arthritis, where only one of the three main parts of the knee has been affected. The majority of patients needing knee replacement surgery will need a total knee replacement.

The inner half of the joint between the thigh bone and shin bone is called the medial compartment. Approximately one third of people with knee osteoarthritis will have it only in the medial compartment.

When is partial knee replacement suitable? 

The symptoms will be very similar to those in people with arthritis throughout the joint. Pain, stiffness and progressive deformity are the possible features. There may well be a pre-existing bow-legged deformity which predisposes to medial compartment arthritis as all the load passes through the inner half of the knee.

There are two options once the stage has been reached where knee replacement needs to be considered. Either total knee replacement or a unicompartmental (partial) knee replacement. For a partial knee replacement, the deformity must be correctable, the ligaments must all be intact and the range of knee movement should be preserved.