Adult acquired flatfoot deformity (AAFD) is a painful condition resulting from the collapse of the longitudinal (lengthwise) arch of the foot. As the name suggests, this condition is not present at birth or during childhood. It occurs after the skeleton is fully matured. In the past it was referred to a posterior tibial tendon dysfunction (or insufficiency). But the name was changed because the condition really describes a wide range of flatfoot deformities. AAFD is most often seen in women between the ages of 40 and 60. This guide will help you understand how the problem develops, how doctors diagnose the condition, what treatment options are available.
The most common cause of acquired adult flatfoot is posterior tibial tendon dysfunction. What causes adult acquired flat foot? Fracture or dislocation. Tendon laceration. Tarsal Coalition. Arthritis. Neuroarthropathy. Neurological weakness.
The first stage represents inflammation and symptoms originating from an irritated posterior tibial tendon, which is still functional. Stage two is characterized by a change in the alignment of the foot noted on observation while standing (see above photos). The deformity is supple meaning the foot is freely movable and a ?normal? position can be restored by the examiner. Stage two is also associated with the inability to perform a single-leg heel rise. The third stage is dysfunction of the posterior tibial tendon is a flatfoot deformity that becomes stiff because of arthritis. Prolonged deformity causes irritation to the involved joints resulting in arthritis. The fourth phase is a flatfoot deformity either supple (stage two) or stiff (stage 3) with involvement of the ankle joint. This occurs when the deltoid ligament, the major supporting structure on the inside of the ankle, fails to provide support. The ankle becomes unstable and will demonstrate a tilted appearance on X-ray. Failure of the deltoid ligament results from an inward displacement of the weight bearing forces. When prolonged, this change can lead to ankle arthritis. The vast majority of patients with acquired adult flatfoot deformity are stage 2 by the time they seek treatment from a physician.
Examination by your foot and ankle specialist can confirm the diagnosis for most patients. An ultrasound exam performed in the office setting can evaluate the status of the posterior tibial tendon, the tendon which is primarily responsible for supporting the arch structure of the foot.
Non surgical Treatment
In the early stages, simple pre-fabricated orthotics can help improve the heel position to reduce the mechanical load which is contributing to the symptoms. In advanced stages or long term orthotic use, a plaster of paris or foam box cast can be taken and specific bespoke orthotics manufactured. If the condition develops further a AFO (ankle foot orthotic) may be necessary for greater control. In more advanced stages of symptomatic Adult Acquired flat feet, where the conservative methods of treatment have failed there are various forms of surgery available depending upon the root cause of the issue and severity.
In cases where cast immobilization, orthoses and shoe therapy have failed, surgery is the next alternative. The goal of surgery and non-surgical treatment is to eliminate pain, stop progression of the deformity and improve mobility of the patient. Opinions vary as to the best surgical treatment for adult acquired flatfoot. Procedures commonly used to correct the condition include tendon debridement, tendon transfers, osteotomies (cutting and repositioning of bone) and joint fusions. (See surgical correction of adult acquired flatfoot). Patients with adult acquired flatfoot are advised to discuss thoroughly the benefits vs. risks of all surgical options. Most procedures have long-term recovery mandating that the correct procedure be utilized to give the best long-term benefit. Most flatfoot surgical procedures require six to twelve weeks of cast immobilization. Joint fusion procedures require eight weeks of non-weightbearing on the operated foot - meaning you will be on crutches for two months. The bottom line is, Make sure all of your non-surgical options have been covered before considering surgery. Your primary goals with any treatment are to eliminate pain and improve mobility. In many cases, with the properly designed foot orthosis or ankle brace, these goals can be achieved without surgical intervention.