Clinical Assessment and Management of Foot and Ankle Osteoarthritis: A Review of Current Evidence and Focus on Pharmacological Treatment.

Foot and ankle osteoarthritis (OA) is a common and disabling problem that adversely affects physical function and significantly reduces quality of life. Although the knee was considered to be the lower-limb site most often affected by OA, recent population data showed foot OA is as prevalent as knee OA, and rates increase with advancing years. The most common foot OA sites include the first metatarsophalangeal joint and the midfoot, with the ankle affected less often. Despite the high prevalence and disabling nature of foot and ankle OA, the condition has been neglected by clinical researchers, and there are very few trials investigating non-surgical foot or ankle OA treatment options. There are no accepted clinical diagnostic criteria for foot or ankle OA so imaging remains common. Clinical guidelines based on knee and hip OA research recommend education, exercise, and weight loss in the first instance. Topical non-steroidal anti-inflammatory drugs (NSAIDs) or capsaicin may be used as an adjunct. Failing these approaches, acetaminophen (paracetamol) should be recommended; however, if there is inadequate symptomatic relief, then clinicians should trial an oral NSAID or a cyclo-oxygenase-2 inhibitor. Given that adverse events and co-morbidities are common in the elderly, older patients should be closely monitored. Some studies have investigated intra-articular injections for foot and ankle OA, and there is some evidence to suggest hyaluronic acid may be effective in the short term for ankle OA. With the lack of research on foot or ankle OA treatments, however, robust clinical trials are urgently needed.