Over 60 Million Americans suffer from Adult Acquired Flatfoot
(AAF), otherwise known as Posterior
Tibial Tendon Dysfunction or PTTD. This condition generally occurs in adults from 40-65 years of age, and it usually only occurs in one foot, not both. The Posterior Tibial (PT) Tendon courses along
the inside part of the ankle and underneath the arch of the foot. It is the major supporting structure for the arch. Over time, the tendon becomes diseased, from overuse, and starts to lose it's
strength. As a result, the arch begins to collapse, placing further strain on the PT Tendon, leading to further decrease in tendon strength, which causes further collapse of the arch. This is
described as a progressive deformity because it will generally get worse over time.
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.
The symptom most often associated with AAF is PTTD, but it is important to see this only as a single step along a broader continuum. The most important function of the PT tendon is to work in synergy
with the peroneus longus to stabilize the midtarsal joint (MTJ). When the PT muscle contracts and acts concentrically, it inverts the foot, thereby raising the medial arch. When stretched under
tension, acting eccentrically, its function can be seen as a pronation retarder. The integrity of the PT tendon and muscle is crucial to the proper function of the foot, but it is far from the lone
actor in maintaining the arch. There is a vital codependence on a host of other muscles and ligaments that when disrupted leads to an almost predictable loss in foot architecture and subsequent
It is of great importance to have a full evaluation, by a foot and ankle specialist with expertise in addressing complex flatfoot deformities. No two flat feet are alike; therefore, "Universal"
treatment plans do not exist for the Adult Flatfoot. It is important to have a custom treatment plan that is tailored to your specific foot. That starts by first understanding all the intricacies of
your foot, through an extensive evaluation. X-rays of the foot and ankle are standard, and MRI may be used to better assess the quality of the PT Tendon.
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.
The indications for surgery are persistent pain and/or significant deformity. Sometimes the foot just feels weak and the assessment of deformity is best done by a foot and ankle specialist. If
surgery is appropriate, a combination of soft tissue and bony procedures may be considered to correct alignment and support the medial arch, taking strain off failing ligaments. Depending upon the
tissues involved and extent of deformity, the foot and ankle specialist will determine the necessary combination of procedures. Surgical procedures may include a medial slide calcaneal osteotomy to
correct position of the heel, a lateral column lengthening to correct position in the midfoot and a medial cuneiform osteotomy or first metatarsal-tarsal fusion to correct elevation of the medial
forefoot. The posterior tibial tendon may be reconstructed with a tendon transfer. In severe cases (stage III), the reconstruction may include fusion of the hind foot,, resulting in stiffness of the
hind foot but the desired pain relief. In the most severe stage (stage IV), the deltoid ligament on the inside of the ankle fails, resulting in the deformity in the ankle. This deformity over time
can result in arthritis in the ankle.