Distraction Ankle Arthroplasty

In this treatment for ankle arthritis, a cage is put on the leg in order to stretch the ankle apart. This may seem to be a strange way to treat arthritis of the ankle, but it seems that by stretching the ankle apart by even a small amount, that the cartilage cells of the ankle are rested, and actually may start to form the critical type of cartilage required to correctly lubricate the joint. It has been proven both in the laboratory and with patients that when you stretch a joint and at the same time apply weight to the leg, that the cartilage improves. This has a lot to do with the biology of the cartilage cells.

The ideal patient for this procedure is someone with advanced arthritis of the ankle, but with good alignment of the foot under the leg and without too much deformity of the ankle. If the patient is over the age of 50 then we are more likely to recommend a total ankle joint replacement. This is a particularly good type of treatment when one is trying to avoid a fusion of the ankle joint in the younger patient.

The surgery commences with cleaning out of the ankle joint, either with a minor surgery called arthroscopy where small loose fragments, bone spurs and inflamed tissue inside the ankle is removed. Either at the same operation or a few weeks later, the cage (called an external fixator) is applied to the leg. This is a circular cage or a set of rings on the foot and leg, which allow us to stretch the ankle apart. The ankle is not stretched much at all, and about 5mm (less than a quarter of an inch) is the amount that we try to achieve. The fixator device is left on the ankle for about 10 weeks. During the time that the fixator is on the ankle, the patient is encouraged to walk on the leg as much as possible to stimulate the cartilage. Initially, this is painful, but by about one week is tolerated quite well. Once the fixator is removed, physical therapy and exercises are very important to try to regain as much movement of the ankle as possible. The ankle remains quite uncomfortable for about 6 months, but by one year, 80% of patients notice a significant improvement in pain in the ankle.

Here you can see the before and after XR of the ankle looking at it from the front with the treatment of the ankle distraction arthroplasty. The external fixation device was left on the ankle for 10 weeks in this patient.