Tendonitis can be a common problem in the foot as we continuously walk and use our feet on a daily basis. The posterior tibial tendon can be especially prone to tendonitis as it helps to maintain the arch of the foot and prevent excessive flattening (pronation) of the foot while walking, standing or running. Posterior tibial tendonitis can be a precursor to posterior tibial tendon dysfunction where there is progressive loss of strength in the tendon and a progressive flattening of the arch.
The posterior tibial tendon starts in the deep portion of the calf and runs behind the prominent bone on the inside of the ankle. The tendon continues along towards the foot and inserts into multiple locations on the inside and the bottom of the arch. With each step a tremendous amount of tension and stress is placed is on the posterior tibial tendon as it helps to maintain and recreate the arch of the foot. With each step there is a natural depression and recreation of the arch that allows for shock absorption. The amount of shock absorption or depression of the arch is variable from person to person depending on the architecture of their foot (flatfeet versus a very high arch). It would seem that only a flatfooted person would get posterior tibial tendonitis but this is not always the case. It can happen to people with any foot type, weight or activity level.
Symptoms of posterior tibial tendonitis include pain and swelling along the inside of the ankle and arch along the course of the tendon. Pain is present with exercise, extended periods of walking or standing. This discomfort will usually increase as the disease progresses and is localized along the course of the tendon around the inside of the ankle or along the inside of the arch. This pain initially is absent when at rest but may progress to the point where pain is present even when not active. Pain and swelling are signs of injury to the tendon. The sheath or sleeve that surrounds the tendon will produce excessive amounts of lubricating fluid in an attempt to allow the tendon to glide easier during the healing process. This excessive fluid production results in the swelling the patient sees and feels on the inside of the ankle and arch. In advanced cases the injury to the tendon that started as tendonitis may progress to a full or partial tear of the tendon.
The diagnosis can often be made from your doctor by the history and physical exam. In many instances a MRI or ultrasound will be performed to determine the extent of damage to the posterior tibial tendon. A simple assessment of tendon strength can be performed by standing on the "tip of the toes" on each foot. The affected foot may feel weak and painful in cases of tendonitis. In advanced cases the patient may not be able to lift the heel from the ground as much or not at all in comparison to the unaffected foot.
Treatment can depend on how long the symptoms have been present and if the amount of strength that is lost (if any) in the tendon. Non-steroidal anti-inflammatory medication, physical therapy, rest and orthotics are often first courses of treatment. Injections of cortisone type medications are performed on rare occasions and often accompanied by cast immobilization. These are all designed to decrease the inflammation in and around the tendon and to decrease the stresses placed on the tendon. In more severe cases a cast from the knee down may be utilized from four to six weeks to allow the tendon to completely rest without placing the day-to-day demands of walking on it. If these measures fail to produce acceptable results surgical intervention may be necessary to clean around the tendon and repair any defects in the tendon. Surgical repair is more commonly needed when there is a progressive weakness in the tendon. As mentioned earlier this loss of strength is called posterior tibial tendon dysfunction.