Ankle arthritis is a common source of pain in the lower extremity and can be seen in relatively young people as well as older people. The ankle is the joint that connects the leg to the foot, and motion from the leg is sharply transferred 90 degrees in the direction from a vertical position to the foot, which is horizontal. In this sharp change of direction, the energy generated by walking is transferred as well, and the ankle has to glide efficiently to transfer this motion so that the foot can propel the body forward. The ankle consists of three bones. The upper bones are the two leg bones (the tibia and the fibula), and the lower bone forms the dome of the ankle (the talus). The joint works roughly like a hinge, moving up and down. However, it is more complex than that, as there is some side to side and tilting motion available as well, to account for uneven terrain along with the help of a joint below in the foot that also tilts (the subtalar joint).

The ability of the ankle joint to smoothly glide up and down is largely dependant on healthy cartilage (the soft, smooth surface covering the joint), and the lack of bone spurs or other bone growths on the front or back of the joint that could restrict motion. The most common issue in ankle arthritis is damage to the cartilage that lines the surface of the joint. When cartilage is eroded or chipped away by injury, a bare spot in the joint appears that contains the underlying hard bone. When cartilage across the joint contacts this bone, it too will become eroded, and gradually two bare areas will be present. When bone grinds on bone during joint motion, pain and inflammation can develop. This whole process can gradually spread and can cause significant pain when walking if severe enough. Joint stiffness and pain in the morning become common, and moving long distances becomes difficult due to pain. Swelling can also be present but is not always seen.

Ankle arthritis develops for a wide variety of reasons. Forceful injuries that cause the cartilage to shear off the bone, as well as fractures that disrupt the cartilage surface, can all lead to eventual ankle arthritis. Chronic sports injuries, malformed ankle bones, and other genetic factors can also lead to cartilage destruction. Many people also gradually develop normal wearing of the cartilage surface, with some developing this more than others. As a result, some people are simply prone later in life to developing arthritis of various joints, and the ankle is no exception. Yet another form of arthritis may be due to body-wide inflammatory diseases rather than direct joint wear. These include rheumatoid arthritis, gout, psoriatic arthritis, among others. The disease process for these conditions differs from traditional arthritis, also called osteoarthritis, in ways specific to the individual disease.

Ankle arthritis can be treated in a variety of ways. The goal is to provide better support for the diseased joint and to reduce inflammation. This can be accomplished through ankle supports and ankle bracing (ankle-foot orthosis), anti-inflammatory medications, an injected steroid medication, and physical therapy. When these are not sufficient, or if the ankle arthritis is severe, surgery may be necessary. Ankle surgery can be performed through an open incision or arthroscopically. Many different procedures can be considered to treat ankle arthritis. These can include procedures that clean the cartilage and remove unhealthy joint tissue, procedures that transplant cartilage plugs to small defects, procedures that remove spurs, procedures that fuse the ankle bones together, or procedures that implant an artificial ankle joint. The selection of these procedures varies according to age, weight, bone density, arthritis severity, and general health.