This condition is a progressive collapse of the tendons and ligaments that hold up the foot?s arch. This condition most commonly affects women. It typically occurs in only one foot, but in some cases, both feet are afflicted.
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.
Symptoms shift around a bit, depending on what stage of PTTD you?re in. For instance, you?re likely to start off with tendonitis, or inflammation of the posterior tibial tendon. This will make the area around the inside of your ankle and possibly into your arch swollen, reddened, warm to the touch, and painful. Inflammation may actually last throughout the stages of PTTD. The ankle will also begin to roll towards the inside of the foot (pronate), your heel may tilt, and you may experience some pain in your leg (e.g. shin splints). As the condition progresses, the toes and foot begin to turn outward, so that when you look at your foot from the back (or have a friend look for you, because-hey-that can be kind of a difficult
maneuver to pull off) more toes than usual will be visible on the outside (i.e. the side with the pinky toe). At this stage, the foot?s still going to be flexible, although it will likely have flattened somewhat due to the lack of support from the posterior tibial tendon. You may also find it difficult to stand on your toes. Finally, you may reach a stage in which your feet are inflexibly flat. At this point, you may experience pain below your ankle on the outside of your foot, and you might even develop arthritis in the ankle.
The diagnosis of tibialis posterior dysfunction is essentially clinical. However, plain radiographs of the foot and ankle are useful for assessing the degree of deformity and to confirm the presence or absence of degenerative changes in the subtalar and ankle articulations. The radiographs are also useful to exclude other causes of an acquired flatfoot deformity. The most useful radiographs are bilateral anteroposterior and lateral radiographs of the foot and a mortise (true anteroposterior) view of the ankle. All radiographs should be done with the patient standing. In most cases we see no role for magnetic resonance imaging or ultrasonography, as the diagnosis can be made clinically.
Non surgical Treatment
Treatment depends very much upon a patient?s symptoms, functional goals, degree and specifics of deformity, and the presence of arthritis. Some patients get better without surgery. Rest and immobilization, orthotics, braces and physical therapy all may be appropriate. With early-stage disease that involves pain along the tendon, immobilization with a boot for a period of time can relieve stress on the tendon and reduce the inflammation and pain. Once these symptoms have resolved, patients are often transitioned into an orthotic that supports the inside aspect of the hindfoot. For patients with more significant deformity, a larger ankle brace may be necessary.
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.