Ankle arthrodesis is a surgical operation carried out on the ankle bone to relieve pain. The pain is usually the result of rheumatoid arthritis that eventually wears out the articular cartilage that allows the joints to work smoothly. This can leave the ankle joint deformed and very painful, particularly when putting weight on the ankle, such as in walking or standing.
The procedure itself consists of a fusion of the ankle joint. After the operation, there are several stages in the healing process, including a series of casts holding the ankle in place.
Alternative Treatments Before Ankle Arthrodesis is Considered
Like most arthritic conditions involving joint deformity and wear, surgery is the last resort for pain relief of an arthritic ankle joint. However, there are a few other alternatives to surgery including;
- Ankle Foot Orthoses (AFO): There are several types of AFO, the leaf spring type being most popular. This consists of a rigid plastic sheath in the form of a splint that is fitted to the calf, reaching from below knee to the ankle and down under the foot. It is worn inside the shoe, with velcro straps holding it tight against the calf, providing support and stability to the ankle joint.
- Cortisone Injections: These can provide temporary pain relief, although there is a limit to the number and frequency of injections. The ankle joint is one of the more painful steroid injection sites.
- Orthotics: These are in the form of specially made shoes, sometimes using insoles with built-in raises, or a rocker imbedded into the sole of the shoe.
- Medication: Medication consists of anti-inflammatory drugs and analgesics.
Anatomy of the Ankle – an Overview
The ankle joint is made up of three bones that are encapsulated at their ends by articular cartilage. This cartilage allows the smooth and natural movement of a normal ankle joint.
Below is a sketch showing the joints fused in an arthrodesis operation.
Ankle Arthrodesis and Bone Graft Healing Time
The healing time for ankle arthrodesis with a bone graft can range from 10 to 12 weeks depending on the particular procedure used.
The operation consists of cutting back the ends of the bones to be fused, leaving an even surface. Bone grafts taken from the patient's hip, or donor graft bone, are laid along the surfaces of the bones to be pinned. Pins are then screwed through the bones to hold them securely together.
A padded plaster cast is wrapped around the ankle, and this is replaced by a short-leg cast after two weeks. This cast remains in place for four weeks. During this period, it is imperative that no weight is placed on the joint.
When the short-leg cast is removed, the wound checked and x-rays taken to monitor joint fusion. A weight-bearing plaster is then applied, and this is removed after a further six weeks. Pain and swelling may continue for some time after this period.