Treating Peroneal Tendon Tears and Tendonitis

The peroneal tendons are the tendons that connect the muscles of the outer side of the calf to the foot. These tendons may be affected by inflammation (tendonitis) or tears. Learn more about these tendons and their associated conditions.

Peroneal Tendon Anatomy and Function

The two major peroneal muscles (peroneus longus and peroneus brevis) are situated on the outside of the leg, just adjacent to the calf muscles. The peroneal tendons course along the outer side of the ankle and attach to the foot, connecting these muscles to bone.

The peroneal muscles are important at everting the foot—the motion of rocking the foot outward from the ankle. In normal gait, the motion of the peroneal muscles is balanced by the muscles that invert the foot (rock the foot inward from the ankle).​

The two peroneal tendons are very closely related—in fact, they sit one on top of the other right behind the fibula. This close relationship is thought to contribute to some of the problems that occur to the peroneal tendons, as they rub together behind the ankle.

Peroneal Tendonitis

The most common problem that occurs with the peroneal tendons is inflammation or tendonitis. The tendons are usually inflamed just behind the fibula bone at the ankle joint. This part of the fibula is the bump on the outside of the ankle (also referred to as the lateral malleolus), and the peroneal tendons are located just behind that bony prominence.

Peroneal tendonitis can either be the result of repetitive overuse or an acute injury. Typical symptoms of peroneal tendonitis include pain behind the ankle, swelling over the peroneal tendons, and tenderness of the tendons. Pain is usually worsened if the foot is pulled down and inwards, stretching the peroneal tendons.

X-rays of the ankle are typically normal. Magnetic resonance imaging (MRI) may show inflammation and fluid around the tendons.

Typical treatment of peroneal tendonitis is accomplished with some simple steps, including:

• Ice application: Applying ice to the area can help to reduce swelling and help to control pain.
• Rest: Rest is key and often helped with the use of a supportive device, or crutches in severe cases.
• Walking boot/ankle brace: Braces and boots provide support and can reduce stress on the tendons and allow for rest and inflammation to subside.
• Anti-inflammatory medications: Medications, such as Motrin or Aleve (ibuprofen), are anti-inflammatory and can reduce the swelling around the tendon.
• Physical therapy: Physical therapy can be beneficial to help restore normal ankle joint mechanics.
• Cortisone injections: Cortisone injections are rarely used, as they can lead to tendon damage. However, in some cases of recurrent tendonitis that does not improve, a shot of cortisone may be considered.

Peroneal Tendon Tears

Tears of the peroneal tendons can occur, and are more likely to occur in the peroneus brevis tendon. Tears are thought to be the result of two issues with the tendon.

One issue is the blood supply. Tears of the peroneus brevis almost always occur in the watershed zone where the blood supply, and thus nutrition of the tendon, is poorest.

The second issue is the close relationship between the two tendons, causing the peroneus brevis to be wedged between the peroneus longus tendon and the bone.

Tears of the peroneus brevis are often treated with the same treatments for tendonitis listed above. In fact, about half of tears diagnosed by imaging are found to be asymptomatic.

For patients who don't find lasting relief of symptoms, surgery may be necessary. There are two main surgical options for peroneal tendon tears:

• Tendon debridement and repair: During a tendon debridement, the damaged tendon and inflammatory tissue surrounding can be removed. The tendon tear can be repaired, and the tendon is "tubularized," restoring its normal shape. Tendon debridement and repair is most effective when less than 50% of the tendon is torn.
• Tenodesis: A tenodesis is a procedure where the damaged tendon is sewn to the normal tendon. In this case, the damaged segment of peroneal tendon is removed (usually a few centimeters), and the ends left behind are sewn to the adjacent remaining peroneal tendon. Tenodesis is often recommended for tears that involve greater than 50% of the tendon.

Recovery after surgery can involve several weeks of restricted weight-bearing and immobilization, depending on the type of surgery performed. Following immobilization, therapy can begin.

Total time for recovery is usually six to 12 weeks, depending on the extent of surgery. Risks of surgery include infection, stiffness, and persistent pain. That said, the surgery can be successful, with some studies reporting that 85% to 95% of patients are able to resume playing sports.