A Guide To Conservative Care For Adult Flatfoot
In recent years, the management of adult flatfoot has shifted from early surgical treatment to more conservative options for this commonly seen condition. Accordingly, these authors discuss the evaluation of adult flatfoot and enumerate various conservative methods to consider as initial treatment.
Adult flatfoot is a common problem we, as podiatrists, see every day. Without early identification of the problem, the flatfoot deformity can progress.
There has been a shift in protocol over the years from surgical treatment early on in the diagnosis of adult flatfoot to a more valiant attempt at conservative treatment. In 1997, Sferra and Rosenberg stated that “conservative management is a critical part of initial treatment of posterior tibial tendon insufficiency, especially in patients with advanced age, sedentary lifestyle and medical comorbidities that preclude surgical intervention.”1
In order to provide adequate treatment, whether it is surgical or conservative, to a patient with flatfoot, it is important to evaluate the patient clinically and radiographically to determine the cause of his or her flatfoot deformity. During the physical exam, the patient should stand during the observation. The physician should look for asymmetrical swelling, abduction of the forefoot and pes planus.
One should perform the bilateral heel rise test. When the heels appear asymmetrical or there is not a complete heel rise, consider posterior tibial tendon dysfunction (PTTD). Also perform the single limb heel rise. Incomplete inversion of the heel on toe rise or difficulty performing this test should alert the practitioner to a problem with the posterior tibial tendon.
During a seated exam, palpation of the tendon is necessary to evaluate soft tissue swelling and tenderness along the course of the tendon. To test motor strength, the podiatric physician should have the patient invert the foot against resistance with the foot plantarflexed to keep the tibialis anterior from substituting.2
Radiographic evaluation reveals lateral subluxation of the talonavicular joint, an increase in the talo-first metatarsal angle and an increase in the divergence of the talus and calcaneus on the AP view. The lateral view will demonstrate plantarflexion of the talus, a decrease in the lateral talocalcaneal angle and collapse of the longitudinal arch. As the deformity progresses, the subtalar and talonavicular joints narrow. Ankle radiographs show arthritis and talar tilt in a longstanding deformity.3
After clinically and radiographically evaluating the patient with a flatfoot deformity, it is important to distinguish between a flexible and rigid deformity. One can do this by evaluating the range of motion of the subtalar joint and perform the Hubscher maneuver (“Jack’s test”). If the arch cannot be recreated and the subtalar joint motion is limited, one must suspect a tarsal coalition or rigid flatfoot.
After determining whether the flatfoot deformity is rigid or flexible, the clinician should further evaluate the flexible flatfoot to determine the level of involvement of the posterior tibial tendon (PTT). The PTT is often the culprit of flexible adult flatfoot. The tendon is located posterior to the axis of the tibiotalar joint and medial to the axis of the subtalar joint. It functions to plantarflex and invert the foot.4-6
The PTT also creates a rigid lever during gait. When it is not functioning properly, the tendon is unable to form the rigid lever needed for gait and the forward propulsion of the gastroc-soleus complex acts at the midfoot, thus causing midfoot collapse.7,8 The PTT is injured by a combination of vascular insufficiency and the mechanical pulley of the tendon along the medial malleolus.
A Primer On PTTD Classifications
Johnson and Strom developed a PTTD classification system, which was later modified by Myerson to include stage IV.9,10