Peroneal Nerve Entrapment at the Fibular Head

Definition

Compression of the peroneal nerve where it passes under the peroneous longus muscle near the fibular head, just below the knee. Symptoms include burning and tingling on the shin and the top of the foot that is worsened with walking, and especially with squatting. In more advanced cases, patients have weakness lifting up their foot (i.e., foot drop).

Diagnosis

Diagnosis is made by a history and physical examination by your physician. It is then confirmed with electrical studies done in the office. Patients commonly have tenderness near the fibular head and electrical shocks that shoot to the foot when this area is touched. It is very important to exclude a herniated disc in the lower back as an alternative cause. This is usually done with an electrical test or MRI, if indicated.

Treatment Options

The first line of treatment is avoiding activity that makes the pain worse, especially prolonged squatting. Steroid injections near the peroneal nerve at the fibular head help some patients, but recurrences are common. Some medications may help relieve the discomfort, but they are not FDA-approved for this condition. If the patient has a foot drop, then an ankle splint is prescribed. In general, when symptoms persist for longer than three months despite these above conservative measures, surgery is an option.

Surgery

Decompression of the peroneal nerve at the fibular head is performed in day surgery with the skin numbed with lidocaine and the patient sedated. Using a 3-inch incision, the procedure takes about 30-40 minutes. During surgery the skin is incised, and then the peroneal nerve is identified under the skin and followed to where it is compressed by fascia and muscle near the fibular head. All compression points are released and it is made certain the fibula itself is not compressing the nerve. The skin is closed with sutures that absorb by themselves under the skin. A simple, occlusive dressing is applied.

Serial operative
photographs of a peroneal
nerve decompression.
The fascial and muscular
compression points are released

Complications

Although surgical decompression of the peroneal nerve is quite safe, the efficacy of this procedure is somewhat uncertain. Nevertheless, most patients experience improvement after surgery. There is about a 1-2% chance of infection, which may require antibiotics. Some swelling near the wound is normal and resolves in about a week or two. The chance of nerve damage is remote, being much less than 1%.

Day of Surgery

Peroneal nerve release at the fibular head is performed in day surgery. Since sedation 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 occlusive dressing is applied to the incision, which should be kept in place for three days. You may shower. On the third day, the dressing is removed revealing small stickers covering the wound. These are left alone until you visit the surgeon a week after surgery. You may shower and these stickers can get wet. You are allowed to bear weight on the operated leg immediately after surgery, but should "take it easy" for the first week after surgery. Pain is usually minimal, but the occasional Tylenol or Tylenol with codeine may be required. The leg should be elevated above the heart whenever possible for the first 3 days after surgery to prevent swelling. If you experience severe or progressive pain or bleeding, you should call the surgeon. Some spotting on the dressing with blood is normal. The dressing is changed when you visit the surgeon a week after surgery.

Recovery

Avoiding athletic activity and excessive standing and walking during the first week after surgery allows the wound heal well. For patients who only do light work in an office setting, they can return to work a few days after surgery. After about two weeks, 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.

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