The posterior tibialis muscle originates on the bones of the leg (tibia and fibula). This muscle then passes behind the medial (inside) aspect of the ankle and attaches to the medial midfoot as the posterior tibial tendon. The posterior tibial tendon serves to invert (roll inward) the foot and maintain the arch of the foot. This tendon plays a central role in maintaining the normal alignment of the foot and also in enabling normal gait (walking). In addition to tendons running across the ankle and foot joints, a number of ligaments span and stabilize these joints. The ligaments at the medial ankle can become stretched and contribute to the progressive flattening of the arch. Several muscles and tendons around the ankle and foot act to counter-balance the action of the posterior tibial tendon. Under normal circumstances, the result is a balanced ankle and foot with normal motion. When the posterior tibial tendon fails, the other muscles and tendons become relatively over-powering. These muscles then contribute to the progressive deformity seen with this disorder.
Overuse of the posterior tibial tendon is often the cause of PTTD. In fact, the symptoms usually occur after activities that involve the tendon, such as running, walking, hiking, or climbing stairs.
Depending on the cause of the flatfoot, a patient may experience one or more of the different symptoms here. Pain along the course of the posterior tibial tendon which lies on the inside of the foot and ankle. This can be associated with swelling on the inside of the ankle. Pain that is worse with activity. High intensity or impact activities, such as running, can be very difficult. Some patients can have difficulty walking or even standing for long periods of time. When the foot collapses, the heel bone may shift position and put pressure on the outside ankle bone (fibula). This can cause pain on the outside of the ankle. Arthritis in the heel also causes this same type of pain. Patients with an old injury or arthritis in the middle of the foot can have painful, bony bumps on the top and inside of the foot. These make shoewear very difficult. Occasionally, the bony spurs are so large that they pinch the nerves which can result in numbness and tingling on the top of the foot and into the toes. Diabetics may only notice swelling or a large bump on the bottom of the foot. Because their sensation is affected, people with diabetes may not have any pain. The large bump can cause skin problems and an ulcer (a sore that does not heal) may develop if proper diabetic shoewear is not used.
Your podiatrist is very familiar with tendons that have just about had enough, and will likely be able to diagnose this condition by performing a physical exam of your foot. He or she will probably examine the area visually and by feel, will inquire about your medical history (including past pain or injuries), and may also observe your feet as you walk. You may also be asked to attempt standing on your toes. This may be done by having you lift your ?good? foot (the one without the complaining tendon) off the ground, standing only on your problem foot. (You may be instructed to place your hands against the wall to help with balance.) Then, your podiatrist will ask you to try to go up on your toes on the bad foot. If you have difficulty doing so, it may indicate a problem with your posterior tibial tendon. Some imaging technology may be used to diagnose this condition, although it?s more likely the doctor will rely primarily on a physical exam. However, he or she may order scans such as an MRI or CT scan to look at your foot?s interior, and X-rays might also be helpful in a diagnosis.
Non surgical Treatment
Depending on the stage of the deformity and patient?s functional goals, various treatment options are available. Some patients improve with conservative care which includes rest and immobilization, shoe modifications, orthoses and bracing, or physical therapy. Surgery might be warranted for advanced stages of the condition. Often a combination of procedures including tendon and muscle augmentation, tendon transfers, realigning of bones or fusion of certain joints might be necessary in more advanced cases. Your doctor will evaluate and recommend an individualized plan of care with your specific needs in mind.
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.