The ankle joint is formed by the leg bones (tibia and fibula) and the talus. This joint allows the foot to move up and down. The sideways (inversion/eversion) movement of the heel is mainly the joint under the talus (sub-talar joint). Normally the three bones of the ankle joint are covered by smooth articular cartilage which allows the bones to glide over each other and the joint to move up and down freely.
Osteoarthritis may occur spontaneously in the ankle joint but is more commonly associated with an injury (usually years before). A severe sprain or repeated sprains with damage to the articular cartilage of the talus can lead to progressive arthritis as can fractures around the ankle joint. Click here for link to sprains
Rheumatoid arthritis and other causes of 'inflammatory arthritis" can affect the ankle as part of the generalised effect on joints.
What are the symptoms
Roughening of the joint surface leads to stiffness and pain. Inflammation can cause swelling of the ankle joint. During the early stages, there may be discomfort during exercise which settles with rest. As the arthritis advances, normal walking or weight-bearing becomes painful and eventually it may become a constant pain even at rest. Progressively, the joint surface is eroded with collapse of the bone surfaces which may lead to a deformity of the foot with the heel turning in or out when standing.
What is the treatment
Continuing pain in the ankle following a sprain may commonly be due to damage to the articular surface of the talus (osteochondral defect). This may be successfully treated by the minimally invasive procedure of an ankle arthroscopy as a day-case. Click here for a link to ankle arthroscopy
The mainstay of treatment for osteoarthritis of the ankle is control of pain and inflammation with analgesics (pain-killers) and anti-inflammatory tablets. A brace may help reduce pain and support the joint when walking.
When is an operation indicated and what operations are possible
When the pain interferes with usual daily activities or sleeping is difficult despite taking analgesics an operation is considered. If there is progressive deformity of the ankle joint then surgery may be recommended before damage occurs to other joints around the ankle (eg sub-talar joint).
The two main options for treatment are ankle fusion or ankle replacement.
This has been the 'Gold Standard" method for treating ankle arthritis for over 50 years. It involves removing the damaged articular cartilage from the bones of the ankle joint and then fusing the bones together by holding them with screws. Whilst the fusion takes place, the ankle is supported in a cast or a boot for 12 weeks. The purpose of the operation is to leave the ankle joint stiff but pain free. Many patients are concerned that the stiff ankle will cause difficulty with walking and a pronounced limp. This is not normally the case - although the ankle is stiff, the other joints (sub-talar joint and foot joints) remain mobile. Therefore walking is generally not affected when mobilising on flat surfaces and patients automatically turn out the foot when walking up a slope.
With the advent of improved arthroscopic equipment an ankle fusion may now be performed as a minimally-invasive procedure in some patients. This has the benefit of improved wound-healing and there is also evidence that it also leads to earlier fusion. (Click here for a link to operation information)
Newer designs of total ankle replacements mean that this operation is becoming a very real alternative to ankle fusion. (The "Mobility" Total Ankle Replacement is shown below)
The advantage of an ankle replacement is that it may provide patients with excellent relief of pain whilst maintaining movement of the ankle joint. In the mid-term (up to10 years) it appears to be a very promising operation with thousands of satisfied patients treated world-wide.
Although many successful results have been published in the literature, there is not yet the wealth of evidence with long-term follow-up (20 years) that is available for total hip replacement. Some of the best results have been shown in patients over 60 years of age and those with rheumatoid arthritis.
For carefully selected patients total ankle replacement now offers an exciting and viable method for treating ankle arthritis.
(Click here for a link to operation information)