Peroneal tendinopathy is degeneration of the peroneal tendon, which runs along the lower, outside portion of the ankle.
These tendons attach the peroneus longus and peroneus brevis muscles to bone, extending from the lower leg to the toes. The peroneus muscles pass around the outside of the ankle, providing stability and balance to the foot and ankle. These muscles allow you to point your toe and rotate your foot outward.
The chronic version of this condition typically has a gradual onset, over weeks or months of activity. Acutely, it may manifest in a sudden onset of pain along the outside ankle and foot.
Causes of Peroneal Tendinopathy
Peroneal tendinopathy is an overuse injury, most common in patients who have recently taken up a new sport or type of exercise. This condition is also common in those who increase their workout intensity or duration quickly, rather than ramping up slowly.
Runners, basketball players, dancers, skaters and patients with weak ankles or previous ankle injuries face an increased risk of developing this condition.
Inappropriate footwear, weak supporting muscles and poor biomechanical techniques can also trigger problems in the peroneal tendons. If your foot strikes primarily on the outside (supination), or if your heel turns inward (hindfoot varus), both the tendons and the muscles bear unusually high levels of stress.
Symptoms and Diagnosis of Peroneal Tendinopathy
In peroneal tendinopathy, the tendons can become swollen, thickened or enlarged. Symptoms include swelling and aching pain or tenderness in the outer ankle. The pain typically manifests during use and when rotating the foot outward. You may also feel pain when pointing your toe or walking on a sloped surface, or you may have weakness when rotating the foot inward.
A key characteristic of this condition is that symptoms lessen or disappear with rest, but return when you resume your normal level of activity.
To diagnose this overuse injury, the doctor will be especially diligent in taking your medical history. Because peroneal tendon problems tend to mimic other types of ankle injuries, such as a lateral ankle sprain or a stress reaction of the bone, your medical and activity history is a key factor in correctly diagnosing the problem.
The doctor will perform a manual exam to identify specific areas of pain, swelling, tenderness and weakness. Imaging tests, specifically ultrasound or MRI, may be ordered to verify the diagnosis and rule out other potential problems.
Peroneal Tendinopathy Treatment and Prevention
For many patients, this condition responds well to the RICE protocol of rest, ice, compression and elevation. Minimizing weight-bearing activities is crucial for facilitating recovery. The doctor may also prescribe nonsteroidal anti-inflammatory drugs (NSAIDs) to control pain and reduce inflammation, and a brace or boot if you have significant pain walking.
For those patients who do not respond well to conservative treatment strategies, guided injections can facilitate healing. Platelet-rich plasma (PRP) injections can be especially effective for treating peroneal tendinopathy.
Once symptoms have decreased, you will begin a regimen of physical therapy and strength training to restore function, range of motion and balance.
A full biomechanical evaluation and functional movement screening will help ensure that this painful condition does not recur. Using the results, the doctor will develop a personalized training regimen designed to correct your gait and movement. This will not only help improve your performance, but it will also help prevent the recurrence of peroneal tendinopathy.
A small number of patients may have to undergo orthopedic surgery, but only if less-invasive treatment protocols fail to provide relief over time, or if other damage is discovered.