Overview
PTTD is a common condition treated by foot and ankle specialists. Although there is a role for surgical treatment of PTTD, conservative care often can prevent or delay surgical intervention. Decreasing inflammation and stabilizing the affected joints associated with the posterior tibial tendon can decrease pain and increase functional levels. With many different modalities available, aggressive nonoperative methods should be considered in the treatment of PTTD, including early immobilization, the use of long-term bracing, physical therapy, and anti-inflammatory medications. If these methods fail, proper evaluation and work-up for surgical intervention should be employed.
Causes
A person with flat feet has greater load placed on the posterior tibial tendon which is the main tendon unit supporting up the arch of the foot. Throughout life, aging leads to decreased strength of muscles, tendons and ligaments. The blood supply diminishes to tendons with aging as arteries narrow. Heavier, obese patients have more weight on the arch and have greater narrowing of arteries due to atherosclerosis. In some people, the posterior tibial tendon finally gives out or tears. This is not a sudden event in most cases. Rather, it is a slow, gradual stretching followed by inflammation and degeneration of the tendon. Once the posterior tibial tendon stretches, the ligaments of the arch stretch and tear. The bones of the arch then move out of position with body weight pressing down from above. The foot rotates inward at the ankle in a movement called pronation. The arch appears collapsed, and the heel bone is tilted to the inside. The deformity can progress until the foot literally dislocates outward from under the ankle joint.
Symptoms
Posterior tibial tendon insufficiency is divided into stages by most foot and ankle specialists. In stage I, there is pain along the posterior tibial tendon without deformity or collapse of the arch. The patient has the somewhat flat or normal-appearing foot they have always had. In stage II, deformity from the condition has started to occur, resulting in some collapse of the arch, which may or may not be noticeable. The patient may feel it as a weakness in the arch. Many patients initially present in stage II, as the ligament failure can occur at the same time as the tendon failure and therefore deformity can already be occurring as the tendon is becoming symptomatic. In stage III, the deformity has progressed to the extent where the foot becomes fixed (rigid) in its deformed position. Finally, in stage IV, deformity occurs at the ankle in addition to the deformity in the foot.
Diagnosis
Looking at the patient when they stand will usually demonstrate a flatfoot deformity (marked flattening of the medial longitudinal arch). The front part of the foot (forefoot) is often splayed out to the side. This leads to the presence of a ?too many toes? sign. This sign is present when the toes can be seen from directly behind the patient. The gait is often somewhat flatfooted as the patient has the dysfunctional posterior tibial tendon can no longer stabilize the arch of the foot. The physician?s touch will often demonstrate tenderness and sometimes swelling over the inside of the ankle just below the bony prominence (the medial malleolus). There may also be pain in the outside aspect of the ankle. This pain originates from impingement or compression of two tendons between the outside ankle bone (fibula) and the heel bone (calcaneus) when the patient is standing.
Non surgical Treatment
The following is a summary of conservative treatments for acquired flatfoot. Stage 1, NSAIDs and short-leg walking cast or walker boot for 6-8 weeks; full-length semirigid custom molded orthosis, physical therapy. Stage 2, UCBL orthosis or short articulated ankle orthosis. Stage 3, Molded AFO, double-upright brace, or patellar tendon-bearing brace. Stage 4, Molded AFO, double-upright brace, or patellar tendon-bearing brace.
Surgical Treatment
Surgical treatment should be considered when all other conservative treatment has failed. Surgery options for flatfoot reconstruction depend on the severity of the flatfoot. Surgery for a flexible flatfoot deformity (flatfoot without arthritis to the foot joints) involves advancing the posterior tibial tendon under the arch to provide more support and decrease elongation of the tendon as well as addressing the hindfoot eversion with a osteotomy to the calcaneus (surgical cut in the heel bone). Additionally, the Achilles tendon may need to be lengthened because of the compensatory contracture of the Achilles tendon with flatfoot deformity. Flatfoot deformity with arthritic changes to the foot is considered a rigid flatfoot. Correction of a rigid flatfoot deformity usually involves surgical fusion of the hindfoot joints. This is a reconstructive procedure which allows the surgeon to re-position the foot into a normal position. Although the procedure should be considered for advanced PTTD, it has many complications and should be discussed at length with your doctor.