A tendon is a band of tissue that connects a muscle to a bone. The two peroneal tendons are behind the outer ankle bone. One of the peroneal tendons attaches to the outer part of the midfoot, while the other tendon 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. Peroneal tendon damage can often times occur with repeated sprains and Chronic Ankle Instability.
Causes
Peroneal tendon injuries can occur acutely (suddenly) or chronically (over a period of time). Damage commonly occurs in patients who participate in sporting activities or have problems with Chronic Ankle Instability. Sometimes people with high arches (Cavus Foot) are at risk for developing peroneal tendon injuries. Types of peroneal tendon injuries are tendonitis, tears, and subluxation.
- Tendonitis, is inflammation of one or both tendons. The inflammation is caused by activities involving repetitive use of the tendon, overuse of the tendon, or trauma (ankle sprains).
- Acute tears, are typically caused by repetitive activity or trauma. They can be complete tears or small incomplete tears. As time goes on, these tears may lead to a change in the shape of the foot, in which the arch may become higher.
- Degenerative tears (tendonosis), due to overuse and occur over long periods of time – sometimes years. In degenerative tears, the tendon is overstretched until it becomes thin and eventually frays. High arches puts you at risk for developing a degenerative tear.
- Subluxation, one or both tendons have slipped out of their normal position. This can be predisposed by the shape of the bone or the size of the muscle belly. At times subluxation can occur following trauma, such as an ankle sprain or repeated ankle sprains. Damage or injury to the tissues that stabilize the tendons (retinaculum – seat belt that keeps the tendons in their groove) can lead to chronic tendon subluxation.
Symptoms
- Pain to the outside of the ankle
- Swelling to the outside of the ankle
- Weakness or instability of the foot and ankle
- Increase in the height of the arch
- Snapping feeling of the tendon on the outside of the ankle
Diagnosis
To diagnose a peroneal tendon injury, the surgeon will examine the foot and look for pain, instability, swelling, warmth, and weakness on the outside of the ankle.
X-rays will be ordered to evaluate any bony abnormalities. An MRI and Ultrasound will also be ordered to fully evaluate the tendons. These tests will look at the quality of the tendon with and without movement. This is to determine the extent of the pathology to the outside of the ankle and peroneals as well as determine surgical planning should surgery be warranted.
Non Surgical Treatments
- Rest. Limit the amount you are on the injured ankle.
- Immobilization. A cast or splint may be used to keep the foot and ankle from moving and allow the injury to heal.
- Ice. Apply an ice pack to the injured area, placing a thin towel between the ice and the skin. Use ice for 20 minutes and then wait at least 40 minutes before icing again.
- Compression. An elastic wrap may be recommended by your surgeon to control swelling.
- Bracing. The ankle should be supported in a low profile ASO brace as rehabilitation develops.
- Elevation. The ankle should be raised slightly above the level of your heart to reduce swelling.
- Physical therapy. Your surgeon will start you on a rehabilitation program as soon as possible to promote healing and increase your range of motion. This includes doing prescribed exercises.
- Medications. Nonsteroidal anti-inflammatory drugs (NSAIDs), may be recommended to reduce pain and inflammation. In some cases, prescription pain medications are needed to provide adequate relief.
Surgery
In more severe cases, surgery may be required to adequately treat the chronic ankle sprain and/or the peroneal damage. Surgery often involves repairing the damaged ligament or ligaments, repairing the tendons, deepening the groove of the tendon, repairing the seatbelt over the groove. Your surgeon will select the surgical procedure best suited for your case based on the type and severity of your condition as well as your activity level.