Anatomy
The ankle joint is composed of three bones – the tibia (forming the inner aspect of the ankle); the fibula (forming the outer side of the ankle); and the talus (the lowest bone in the ankle joint). The surfaces of the bones are covered with articular cartilage, a material that allows the bones to move smoothly over each other. A number of ligaments are attached to these bones to help with ankle stability and movement. The ankle joint is a small joint in relation to the load it must bear – it is subject to your full body weight. Hence, any pain from a diseased or injury ankle is disabling.
Ankle Arthritis
Arthritis is a condition where the joint cartilage at the ends of the bones wears away, causing roughened bone surfaces. This can result in pain, stiffness, swelling and reduced movement of the joint. The different types of arthritis are outlined as follows:
- Osteoarthritis (OA): This is an age related arthritis, where the cartilage is worn away over time.
- Rheumatoid arthritis (RA): This is a chronic inflammatory type of arthritis, that destroys the joint cartilage. It can occur at any age.
- Post-traumatic arthritis: This arthritis may develop after an injury to the bones of the ankle.
Non-operative Treatment
Initially, you may gain relief from your ankle arthritis pain by some or all of the following methods: the use of analgesic/anti-inflammatory medications; avoiding/reducing activities that aggravate your arthritis; participating in physiotherapy or non-weightbearing exercises such as swimming or bike riding to help improve muscle strength and joint mobility; losing weight (if appropriate) to help reduce the load on your ankle joints.
If the above methods do not help with the pain and other symptoms of arthritis, a total ankle replacement may be suggested.
Operative Treatment - Total Ankle Replacement
Total ankle replacement surgery involves the removal of the diseased parts of the bones of the ankle. The end of the tibia and the top of the talus are replaced with very high grade medical stainless metal prostheses, with a plastic (high density polyethylene) insert between them. The insert acts as a bearing surface between the metals and prevents them rubbing against each other.
The ankle replacement system used does not require cementing of the prostheses, as they have a porous coating which allows bone ingrowth and a biological union of the prostheses to bone.
Post Operative Treatment
Following surgery, you will have a plaster cast on your ankle, with padded bandages underneath. You may have a wound drain in the ankle, which is usually removed the day after surgery. Crutches will be necessary to assist with non-weight bearing mobilization for about 6-8 weeks.
It is important initially to rest your ankle joint and keep your foot elevated to assist with healing. You may find ice packs help reduce swelling of your ankle. You may be able to commence gentle active movements of your ankle after a couple of weeks. At about the same time, you will be fitted with a Donjoy walkabout boot that you will need to wear until about 12 weeks post surgery Gentle riding on an exercise bike may be suitable about 6 weeks post surgery - Dr Mansfield will advise you on what activities you can commence and when.
Risks/Complications
Possible risks of this surgery include: