Adult flatfoot (adult acquired flatfoot) or posterior tibial tendon dysfunction
(PTTD) is a common pathology presented to foot and ankle
specialists. PTTD is characterized by a valgus (everted) hindfoot, flattening of the longitudinal arch of the foot (collapse) and abduction of the forefoot. This is a progressive deformity that
begins flexible and can become rigid over time. The posterior tibial tendon (PT) is one of the main supporting structures of the foot arch. Changes within this tendon cause flattening of the foot.
There are four stages of this deformity that begins flexible and progressives, with no treatment, to a rigid deformity and with time may involve the ankle joint. Patients usually present with pain in
the foot or ankle stating the ankle is rolling. Its also common for patients to state they have difficulty walking barefoot. Pain is exacerbated after physical activities. Pain is usually isolated to
the inside of the foot along the course of the PT tendon.
Overuse of the posterior tibial tendon is often the cause of PTTD. In fact, the symptoms usually occur after activities that involve the tendon, such as running, walking, hiking, or climbing
Many patients with this condition have no pain or symptoms. When problems do arise, the good news is that acquired flatfoot treatment is often very effective. Initially, it will be important to rest
and avoid activities that worsen the pain.
In the early stages of dysfunction of the posterior tibial tendon, most of the discomfort is located medially along the course of the tendon and the patient reports fatigue and aching on the
plantar-medial aspect of the foot and ankle. Swelling is common if the dysfunction is associated with tenosynovitis. As dysfunction of the tendon progresses, maximum pain occurs laterally in the
sinus tarsi because of impingement of the fibula against the calcaneus. With increasing deformity, patients report that the shape of the foot changes and that it becomes increasingly difficult to
wear shoes. Many patients no longer report pain in the medial part of the foot and ankle after a complete rupture of the posterior tibial tendon has occurred; instead, the pain is located laterally.
If a fixed deformity has not occurred, the patient may report that standing or walking with the hindfoot slightly inverted alleviates the lateral impingement and relieves the pain in the lateral part
of the foot.
Non surgical Treatment
Conservative treatment is indicated for nearly all patients initially before surgical management is considered. The key factors in determining appropriate treatment are whether acute inflammation and
whether the foot deformity is flexible or fixed. However, the ultimate treatment is often determined by the patients, most of whom are women aged 40 or older. Compliance can be a problem, especially
in stages I and II. It helps to emphasise to the patients that tibialis posterior dysfunction is a progressive and chronic condition and that several fittings and a trial of several different
orthoses or treatments are often needed before a tolerable treatment is found.
If initial conservative therapy of posterior tibial tendon insufficiency fails, surgical treatment is considered. Operative treatment of stage 1 disease involves release of the tendon sheath,
tenosynovectomy, debridement of the tendon with excision of flap tears, and repair of longitudinal tears. A short-leg walking cast is worn for 3 weeks postoperatively. Teasdall and Johnson reported
complete relief of pain in 74% of 14 patients undergoing this treatment regimen for stage 1 disease. Surgical debridement of tenosynovitis in early stages is believed to possibly prevent progression
of disease to later stages of dysfunction.