In a minority of patients, arthritis is confined to the patello-femoral joint between the knee cap and the lower end of the thigh bone. Providing the rest of the knee is in a good condition, patients need only be treated by patello-femoral knee replacement.

The advantage of this procedure is that only the diseased part of the knee is replaced and the main weight bearing parts of the knee are preserved. This can be performed on young patients and can easily be converted to a total knee replacement if needed in the future.