Tibialis posterior dysfunction: a common and treatable cause of adult acquired flatfoot

Adults with an acquired flatfoot deformity may present not with foot deformity but almost uniformly with medial foot pain and decreased function of the affected foot (for a list of causes of an acquired flatfoot deformity in adults, see box 1).1 Patients whose acquired flatfoot is associated with a more generalised medical problem tend to receive their diagnosis and are referred appropriately. However, in patients whose “adult acquired flatfoot deformity” is a result of damage to the structures supporting the medial longitudinal arch, the diagnosis is often not made early.2 These patients are often otherwise healthier and tend to be relatively more affected by the loss of function resulting from an acquired flatfoot deformity. The most common cause of an acquired flatfoot deformity in an otherwise healthy adult is dysfunction of the tibialis posterior tendon, and this review provides an outline to its diagnosis and treatment. We seached PubMed for publications by using the keywords “flatfoot” and “tibialis posterior dysfunction”. ### Tibialis posterior dysfunction: a common condition Tibialis posterior dysfunction is well recognised by orthopaedic surgeons specialising in foot and ankle surgery and by podiatrists. However, greater general awareness of this condition is required,2 as most patients presenting to a general practitioner receive a diagnosis of ankle sprain or arthritis. By the time most patients present to a specialist foot and ankle clinic they have had the condition for several years and have consulted numerous doctors.3 Even general orthopaedic surgeons and physiotherapists often miss the diagnosis.3 However, tibialis posterior dysfunction need not remain a “specialist diagnosis” as it is usually diagnosed without any investigations, from a history and physical examination.2 Many patients benefit from relatively simple treatment, such as orthotic devices.4 Population based studies to identify the prevalence of tibialis posterior dysfunction are under way. In elderly people the condition …