Many patients suffer from a collapsing arch or flat foot which can cause pain, instability and difficulty while walking. This condition is more commonly known as Posterior Tibial Tendon Dysfunction (PTTD). PTTD is a progressive flattening of the arch due to loss of function of the Posterior Tibial tendon. As the foot flattens, the tendon will stretch, become insufficient and lose its ability to function. This can have a direct effect on walking and posture, ultimately affecting the ankle, knee and hip. As the condition progresses, the joints in the hind foot may become arthritic and painful.
The most common cause of acquired adult flatfoot is posterior tibial tendon dysfunction. What causes adult acquired flat foot? Fracture or dislocation. Tendon laceration. Tarsal Coalition. Arthritis. Neuroarthropathy. Neurological weakness.
The first stage represents inflammation and symptoms originating from an irritated posterior tibial tendon, which is still functional. Stage two is characterized by a change in the alignment of the foot noted on observation while standing (see above photos). The deformity is supple meaning the foot is freely movable and a ?normal? position can be restored by the examiner. Stage two is also associated with the inability to perform a single-leg heel rise. The third stage is dysfunction of the posterior tibial tendon is a flatfoot deformity that becomes stiff because of arthritis. Prolonged deformity causes irritation to the involved joints resulting in arthritis. The fourth phase is a flatfoot deformity either supple (stage two) or stiff (stage 3) with involvement of the ankle joint. This occurs when the deltoid ligament, the major supporting structure on the inside of the ankle, fails to provide support. The ankle becomes unstable and will demonstrate a tilted appearance on X-ray. Failure of the deltoid ligament results from an inward displacement of the weight bearing forces. When prolonged, this change can lead to ankle arthritis. The vast majority of patients with acquired adult flatfoot deformity are stage 2 by the time they seek treatment from a physician.
There are four stages of adult-acquired flatfoot deformity (AAFD). The severity of the deformity determines your stage. For example, Stage I means there is a flatfoot position but without deformity. Pain and swelling from tendinitis is common in this stage. Stage II there is a change in the foot alignment. This means a deformity is starting to develop. The physician can still move the bones back into place manually (passively). Stage III adult-acquired flatfoot deformity (AAFD) tells us there is a fixed deformity. This means the ankle is stiff or rigid and doesn???t move beyond a neutral (midline) position. Stage IV is characterized by deformity in the foot and the ankle. The deformity may be flexible or fixed. The joints often show signs of degenerative joint disease (arthritis).
Non surgical Treatment
Medical or nonoperative therapy for posterior tibial tendon dysfunction involves rest, immobilization, nonsteroidal anti-inflammatory medication, physical therapy, orthotics, and bracing. This treatment is especially attractive for patients who are elderly, who place low demands on the tendon, and who may have underlying medical problems that preclude operative intervention. During stage 1 posterior tibial tendon dysfunction, pain, rather than deformity, predominates. Cast immobilization is indicated for acute tenosynovitis of the posterior tibial tendon or for patients whose main presenting feature is chronic pain along the tendon sheath. A well-molded short leg walking cast or removable cast boot should be used for 6-8 weeks. Weight bearing is permitted if the patient is able to ambulate without pain. If improvement is noted, the patient then may be placed in custom full-length semirigid orthotics. The patient may then be referred to physical therapy for stretching of the Achilles tendon and strengthening of the posterior tibial tendon. Steroid injection into the posterior tibial tendon sheath is not recommended due to the possibility of causing a tendon rupture. In stage 2 dysfunction, a painful flexible deformity develops, and more control of hindfoot motion is required. In these cases, a rigid University of California at Berkley (UCBL) orthosis or short articulated ankle-foot orthosis (AFO) is indicated. Once a rigid flatfoot deformity develops, as in stage 3 or 4, bracing is extended above the ankle with a molded AFO, double upright brace, or patellar-tendon-bearing brace. The goals of this treatment are to accommodate the deformity, prevent or slow further collapse, and improve walking ability by transferring load to the proximal leg away from the collapsed medial midfoot and heel.
Surgical correction is dependent on the severity of symptoms and the stage of deformity. The goals of surgery are to create a more functional and stable foot. There are multiple procedures available to the surgeon and it may take several to correct a flatfoot deformity. Usually surgical treatment begins with removal of inflammatory tissue and repair of the posterior tibial tendon. A tendon transfer is performed if the posterior tibial muscle is weak or the tendon is badly damaged. The most commonly used tendon is the flexor digitorum longus tendon. This tendon flexes or moves the lesser toes downward. The flexor digitorum longus tendon is utilized due to its close proximity to the posterior tibial tendon and because there are minimal side effects with its loss. The remainder of the tendon is sutured to the flexor hallucis longus tendon that flexes the big toe so that little function is loss.