Another common term for this condition is Posterior Tibial Tendon Dysfunction (PTTD). There is a cause-effect relationship between pronation, flatfoot deformity and subsequent tenosynovitis of the posterior tibial tendon. Mechanical irritation of the tendon may lead to synovitis, partial tearing and eventually full rupture of the tendon. Other structures, including ligaments and the plantar fascia, have also been shown to contribute to the arch collapsing. As the deformity progresses, these structures have been shown to attenuate and rupture as well. In later stages, subluxation of various joints lead to a valgus rearfoot and transverse plane deformity of the forefoot. These deformities can become fixed and irreducible as significant osteoarthritis sets in.
The posterior tibial tendon, which connects the bones inside the foot to the calf, is responsible for supporting the foot during movement and holding up the arch. Gradual stretching and tearing of the posterior tibial tendon can cause failure of the ligaments in the arch. Without support, the bones in the feet fall out of normal position, rolling the foot inward. The foot’s arch will collapse completely over time, resulting in adult acquired flatfoot. The ligaments and tendons holding up the arch can lose elasticity and strength as a result of aging. Obesity, diabetes, and hypertension can increase the risk of developing this condition. Adult acquired flatfoot is seen more often in women than in men and in those 40 or older.
Initially, flatfoot deformity may not present with any symptoms. However, overtime as the tendon continues to function in an abnormal position, people with fallen arches will begin to have throbbing or sharp pain along the inside of the arch. Once the tendon and soft tissue around it elongates, there is no strengthening exercises or mechanism to shorten the tendon back to a normal position. Flatfoot can also occur in one or both feet. If the arch starts to slowly collapse in one foot and not the other, posterior tibial dysfunction (PTTD) is the most likely cause. People with flatfoot may only have pain with certain activities such as running or exercise in the early phase of PTTD. Pain may start from the arch and continue towards the inside part of the foot and ankle where the tendon courses from the leg. Redness, swelling and increased warmth may also occur. Later signs of PTTD include pain on the outside of the foot from the arch collapsing and impinging other joints. Arthritic symptoms such as painful, swollen joints in the foot and ankle may occur later as well due to the increased stress on the joints from working in an abnormal position for a long period of time.
First, both feet should be examined with the patient standing and the entire lower extremity visible. The foot should be inspected from above as well as from behind the patient, as valgus angulation of the hindfoot is best appreciated when the foot is viewed from behind. Johnson described the so-called more-toes sign: with more advanced deformity and abduction of the forefoot, more of the lateral toes become visible when the foot is viewed from behind. The single-limb heel-rise test is an excellent determinant of the function of the posterior tibial tendon. The patient is asked to attempt to rise onto the ball of one foot while the other foot is suspended off the floor. Under normal circumstances, the posterior tibial muscle, which inverts and stabilizes the hindfoot, is activated as the patient begins to rise onto the forefoot. The gastrocnemius-soleus muscle group then elevates the calcaneus, and the heel-rise is accomplished. With dysfunction of the posterior tibial tendon, however, inversion of the heel is weak, and either the heel remains in valgus or the patient is unable to rise onto the forefoot. If the patient can do a single-limb heel-rise, the limb may be stressed further by asking the patient to perform this maneuver repetitively.
Non surgical Treatment
Because of the progressive nature of PTTD, early treatment is advised. If treated early enough, your symptoms may resolve without the need for surgery and progression of your condition can be arrested. In contrast, untreated PTTD could leave you with an extremely flat foot, painful arthritis in the foot and ankle, and increasing limitations on walking, running, or other activities. In many cases of PTTD, treatment can begin with non-surgical approaches that may include. Orthotic devices or bracing. To give your arch the support it needs, your foot and ankle surgeon may provide you with an ankle brace or a custom orthotic device that fits into the shoe. Immobilization. Sometimes a short-leg cast or boot is worn to immobilize the foot and allow the tendon to heal, or you may need to completely avoid all weight-bearing for a while. Physical therapy. Ultrasound therapy and exercises may help rehabilitate the tendon and muscle following immobilization. Medications. Nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, help reduce the pain and inflammation. Shoe modifications. Your foot and ankle surgeon may advise changes to make with your shoes and may provide special inserts designed to improve arch support.
Good to excellent results for more than 80% of patients have been reported at five years’ follow up for the surgical interventions recommended below. However, the postoperative recovery is a lengthy process, and most surgical procedures require patients to wear a plaster cast for two to three months. Although many patients report that their function is well improved by six months, in our experience a year is required to recover truly and gain full functional improvement after the surgery. Clearly, some patients are not candidates for such major reconstructive surgery.