Foot & Ankle

Peroneal Tendon Injuries

Anatomy

The ankle joint connects the leg and the foot. It is formed by three separate bones, the tibia, fibula and talus. The shinbone (tibia) supports most of a person's weight when standing. The outer bone (fibula) is the smaller bone of the lower leg. A small, irregular-shaped foot bone (talus) connects the tibia and fibula. Acting as a hinge, these bones form the ankle.

The foot is a complex, flexible structure that contains bones, joints, and more than 100 muscles, tendons and ligaments, all working together to enable movement and balance. The foot is divided into three sections, the forefoot, the midfoot and the hindfoot. The midfoot contains a pyramid-like group of bones, strengthened by tendons, muscles and ligaments to form three curves, or arches (medial, lateral and fundamental longitudinal), at the bottom of the foot.

Tendons are bands of tissue that attach muscle to bone. The peroneal tendons are two tendons in the foot that run side-by-side behind the outer ankle bone. One peroneal tendon attaches to the outer part of the midfoot, while the other runs under the foot and attaches near the inside of the arch. The main function of the peroneal tendons is to stabilize the foot and ankle and protect them from sprains.

Description

Basic types of peroneal tendon injuries are tendinitis, acute and degenerative tears, and subluxation. Tendinitis is an inflammation of one or both tendons, caused by repetitive activity or overuse of the tendon; or trauma such as an ankle sprain. Acute tears are caused by repetitive activity or trauma, while degenerative tears (tendonosis) are usually due to overuse and may develop over a long period of time—often years. In degenerative tears, the tendon is like taffy that has been overstretched until it becomes thin and eventually frays. When one or both tendons slip out of their normal position, the injury is called a subluxation.

Causes

Peroneal tendon injuries occur most commonly in individuals who participate in sports that involve repetitive or excessive ankle motion. People with higher arches have an increased risk for developing peroneal tendon injuries.

Symptoms

The symptoms of a peroneal tendon injury may vary somewhat, depending on the type and severity of the injury.

• Tendinitis—Pain, swelling, warmth to the touch.
• Acute Tears—Pain, swelling, weakness or instability of the foot and ankle.
• Degenerative tears (tendonosis)—Sporadic pain (occurring from time to time) on the outside of the ankle, weakness or instability in the ankle, an increase in the height of the arch.
• Subluxation—A snapping feeling of the tendon around the ankle bone, sporadic pain behind the outside ankle bone, ankle instability or weakness.

Diagnosis

Peroneal tendon injuries may worsen without proper treatment and are sometimes misdiagnosed, so prompt evaluation by a foot and ankle surgeon is advised. During the examination of your foot, the orthopaedic surgeon will check for pain, instability, swelling, warmth, and weakness on the outer side of the ankle. An X-ray or other advanced imaging studies may be needed to fully evaluate the injury. Prolonged discomfort after a simple sprain may be a sign of additional problems, so your surgeon will also look for signs of an ankle sprain and other related injuries that sometimes accompany a peroneal tendon injury.

Nonsurgical Treatment

• Immobilization—A cast or splint may be used to immobilize the foot and ankle to allow the injury to heal.
• Medications—Oral or injected anti-inflammatory drugs, either over-the-counter or prescribed, may be recommended or prescribed to help relieve the pain and inflammation.
• Physical therapy—Ice, heat, or ultrasound therapy may be used to reduce swelling and pain. As symptoms improve, exercises can be added to strengthen the muscles and improve range of motion and balance. If appropriate, a foot and ankle conditioning program may be prescribed.
• Bracing—The surgeon may provide a brace to use for a short period of time or during activities requiring repetitive ankle motion. Bracing may also be an option when a patient is not a candidate for surgery.

Surgery

In some cases, surgery may be needed to repair the tendon(s) and possibly the supporting structures of the foot. Your orthopaedic surgeon will determine the most appropriate procedure for your condition and lifestyle. After surgery, physical therapy is an important part of rehabilitation.

With any surgery there are some risks, and these vary from person to person. Complications are typically minor, treatable and unlikely to affect your final outcome. Your orthopaedic surgeon will speak to you prior to surgery to explain any potential risks and complications that may be associated with your procedure.