Background

The peroneal muscle and tendons run down the outside of the lower leg and into the foot. The peroneus brevis tendon attaches to a bone on the outside and middle of the foot. The peroneus longus tendon runs under the foot and attaches near the inside of the arch. Together, they serve to help stabilize the foot and ankle. As a result, peroneal tendon injury can often be misdiagnosed as a lateral (outside) sprain of the ankle ligaments. Injury is often from improper or rapid increases in training, or overuse in sports or activities that involve repetitive ankle motion, such as dancers, runners, and soccer players. Athletes with poor fitting shoes, higher arches or inward-turned heels may be at higher risk for developing peroneal tendon injuries due to the increased stress placed on the peroneal tendons. The types of peroneal tendon injuries include tendonitis (inflammation of the tendon), subluxation (movement of the tendon from its normal position), and tendinosis (degenerative tearing of the tendon fibers).

Symptoms

Symptoms can vary, but typically present as pain and swelling along the lateral aspect of the ankle. There may also be a feeling of ankle weakness or instability, especially when pushing off of the toes. In cases of subluxation, a snapping sensation along the outside of the ankle will be felt while walking.

Sports Medicine Evaluation and Treatment

The exam will reveal tenderness along the course of the tendons. Swelling can also be observed depending on the severity and how recent the injury. Often, the injury prevents performing a toe raise or tiptoe walk. The physician will also perform stability tests to assess the degree of the injury.

X-rays will typically be normal, but ultrasound or magnetic resonance imaging (MRI) can show an abnormal appearance or tear of the tendon. Imaging can also be helpful to rule out other ligament or bony injuries, such as fracture or os peroneum syndrome (a condition were an extra bone adjacent to the peroneal tendons can fracture or entrap the surrounding tissues).

Evaluation & Treatment

Treatment involves rest, ice, nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen or naproxen, and a physical therapy regimen that focuses on ankle range-of-motion exercises, peroneal strengthening, and proprioception (balance) training. More severe cases may require immobilization with a walking boot. Steroid injections are often avoided and performed with caution as this can damage the tendon and surrounding nerves. Platelet-rich plasma (PRP) is still being investigated. Indications for surgery include failure of conservative management, recurrent peroneal instability, and rupture of the peroneal tendon. Active subluxation of the tendons may also require surgery as this can lead to rupture without intervention.

Injury Prevention

Prevention should include appropriate preparation prior to exercise or sports seasons, properly fitted shoes, and adequate rehab from ankle or foot injuries.

Return to Play

Return to sports and activity can take months, even after extensive physical therapy, and should be carefully directed by a medical professional.

AMSSM Member Authors
Jason Brucker, MD and Craig Young, MD

References
Baumhauer JF, Nawoczenski DA, DiGiovanni BF, Flemister AS. Ankle pain and peroneal tendon pathology. Clin Sports Med. 2004 Jan;23(1):21-34.
Wilder RP, Sethi S. Overuse injuries: tendinopathies, stress fractures, compartment syndrome, and shin splints. Clin Sports Med. 2004 Jan;23(1):55-81.
Simpson M, Howard T. Tendinopathies of the foot and ankle.” Am Fam Physician. 2009 Nov 15;80(10):1107-1114.
Oh SJ, Kim YH, Kim SK, Kim MW. “Painful os peroneum syndrome presenting as lateral plantar foot pain.” Ann Rehabil Med. 2012 February; 36(1): 163–166.