Definition

Compression of the tibial nerve by a ligament on the inside of your ankle. Symptoms include numbness and burning on the heel and sole of the foot. Tenderness behind your inner ankle may be present. Patients often have previous injuries to the nerves or joints in this region, including ankle fractures, sprain, cysts, and diabetes.

Diagnosis

Diagnosis starts with a history and physical examination. It is then confirmed with electrical studies (i.e., EMG). When tapping the inner ankle, patients often have electrical shocks that shoot to the sole of the foot. It is very important to exclude a pinched nerve in the lower back, generalized nerve damage (neuropathy), and even a tumor in the sciatic nerve by electrical tests or MRI, when indicated.

Treatment Options

The first line of treatment is avoiding activity that makes the pain worse. Comfortable walking shoes and perhaps orthotics can be helpful. Steroid injections near the tibial nerve at the ankle help some patients, but recurrences are common. Some medications may help relieve the discomfort, but if you do not have diabetic neuropathy they are not FDA-approved for this condition. If all other potential causes have been excluded, then decompressive surgery is an option. For patients with severe symptoms who failed previous decompressive surgery, an implantable peripheral nerve stimulator may be useful.

Surgery

Decompression of the tibial nerve at the tarsal tunnel is usually performed in day surgery under general anesthesia without intubation. It is analogous to carpal tunnel surgery, but in the foot. Using a 2-inch incision behind your inner ankle, the procedure takes about 30-40 minutes. During surgery the skin is incised and the tarsal tunnel is opened. The tibial nerve is identified and followed into the foot, where all compression points are released. The skin is closed with sutures that are removed in the office ten days after surgery. An ace bandage is applied.

The tibial neurovascular bundle (arrowhead) compressed by a cyst (asterisk) in the tarsal tunnel.

Complications

Although surgical decompression of the tarsal tunnel is quite safe, the efficacy of this procedure is somewhat uncertain. Nevertheless, most patients experience improvement after surgery. There is about a 2% chance of infection or wound opening after surgery, which may require antibiotics and dressing changes, or even re-operation. Some swelling near the wound and foot is normal and resolves in a few weeks. The chance of nerve damage is remote, being much less than 1%. There is also a risk of the wound pain and tenderness, which is especially problematic in patients with severe pain before surgery.

Day of Surgery

Tarsal tunnel release is performed in day surgery. Since anesthesia is used, you must not eat or drink after midnight the night before surgery. Your medications can be taken the morning of surgery with a sip of water. You arrive one hour before the procedure to meet the anesthesiologist, as well as the surgeon once again. Although the decompression takes about 30-40 minutes, you will be in the operating room for little more than an hour for cleaning, positioning, anesthesia, and dressing the wound. After the procedure, you are observed in the recovery room for about one hour and then are allowed to leave with a friend or family member taking you home.

Discharge Instructions

An ace bandage is applied to the incision, which should be kept in place for three days. You may shower, but the foot should be covered with a plastic bag. You will be given crutches and there should be no weight bearing on the operated foot for about ten days. Whenever possible you should elevate the foot, especially during the first three days after surgery. On the third day after surgery, the ace bandage and dressing are removed revealing small sutures on the wound. A small amount of Neosporin should be applied daily, and covered with gauze. Pain is usually minimal, but the occasional Tylenol or percocet may be required. If you experience severe or progressive pain or bleeding, you should call the surgeon. Some spotting on the dressing with blood is normal. The sutures are removed when you visit the surgeon about ten days after surgery, after which progressive normal foot use is encouraged.

Recovery

The wound mostly heals in about two weeks-however an improvement in your symptoms before surgery may take about 2-3 months. For patients who only do light work in an office setting, they can return to work about a week after surgery. About two weeks after surgery, physical therapy is prescribed by the surgeon or physiatrist, which is performed on a progressive basis for about three months. Although you may visit the physical therapist three times per week in the beginning, once the exercises are learned they can often be performed at home. You will see the surgeon a second time about 2-3 months after the procedure.