A painful flat foot, or adult acquired flatfoot
deformity, is a progressive collapsing of the arch of the foot that occurs as the
posterior tibial tendon becomes insufficient due to various factors. Early stages may present with only pain along the posterior tibial tendon whereas advanced deformity usually results in arthritis
and rigidity of the rearfoot and ankle.
There are a number of theories as to why the tendon becomes inflamed and stops working. It may be related to the poor blood supply within the tendon. Increasing age, inflammatory arthritis, diabetes
and obesity have been found to be causes.
PTTD begins with a gradual stretching and loss of strength of the posterior tibial tendon which is the most important tendon supporting the arch of the human foot. Left untreated, this tendon will
continue to lengthen and eventually rupture, leading to a progressive visible collapse of the arch of the foot. In the early stages, patients with PTTD will notice a pain and swelling along the inner
ankle and arch. Many times, they are diagnosed with ?tendonitis? of the inner ankle. If the foot and ankle are not properly supported during this early phase, the posterior tibial tendon can rupture
and devastating consequences will occur to the foot and ankle structure. The progressive adult acquired flatfoot deformity will cause the heel to roll inward in a ?valgus? or pronated direction while
the forefoot will rotate outward causing a ?duckfooted? walking pattern. Eventually, significant arthritis can occur in the joints of the foot, the ankle and even the knee. Early diagnosis and
treatment is critical so if you have noticed that one, or both, of your feet has become flatter in recent times come in and have it checked out.
The diagnosis of tibialis posterior dysfunction is essentially clinical. However, plain radiographs of the foot and ankle are useful for assessing the degree of deformity and to confirm the presence
or absence of degenerative changes in the subtalar and ankle articulations. The radiographs are also useful to exclude other causes of an acquired flatfoot deformity. The most useful radiographs are
bilateral anteroposterior and lateral radiographs of the foot and a mortise (true anteroposterior) view of the ankle. All radiographs should be done with the patient standing. In most cases we see no
role for magnetic resonance imaging or ultrasonography, as the diagnosis can be made clinically.
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.
Many operations are available for the treatment of dysfunction of the posterior tibial tendon after a thorough program of non-operative treatment has failed. The type of operation that is selected is
determined by the age, weight, and level of activity of the patient as well as the extent of the deformity. The clinical stages outlined previously are a useful guide to operative care (Table I). In
general, the clinician should perform the least invasive procedure that will decrease pain and improve function. One should consider the effects of each procedure, particularly those of arthrodesis,
on the function of the rest of the foot and ankle.