Figure. Radiograph of the right foot with a white arrow showing area of pain.
A 55-year-old woman presents with a complaint of swelling along the posterior fibula of the right ankle. She denies a known injury or precipitating event. She is a mail carrier and walking on uneven ground seems to make the pain worse. On physical examination, she has pain with resisted eversion of the foot and pain to palpation over the proximal fifth metatarsal (Figure). She has tried ice and oral ibuprofen but continues to have persistent posterolateral ankle pain, swelling, and mild ankle eversion weakness.
Submit your diagnosis to see full explanation.
The peroneal tendons include the peroneus brevis and peroneus longus tendons. The primary function of these tendons is for foot eversion and pronation. Both tendons run along the lateral fibular: the peroneus brevis attaches to the base of the fifth metatarsal and the peroneus longus inserts on the plantar aspect of the first metatarsal and medial cuneiform.1 Physical signs of peroneus tendonitis include pain to palpation running along the lateral fibular and pain with resisted eversion of the foot.1,2
Injury to the peroneus tendons can range from tenosynovitis to tendinosis and tearing. These injuries can occur from a number of causes such as an ankle strain from overuse, hindfoot varus deformity, and ankle sprains. Magnetic resonance imaging (MRI) is the best modality to distinguish between these injuries and to look for tendon subluxation and tearing. Treatment of peroneal tendon pain starts with immobilization, ice, and oral anti-inflammatory drugs. A walking boot worn for 3 to 4 weeks generally helps reduce inflammation and should be followed by a slow progression to normal activities. A lateral heel wedge can reduce hindfoot varus taking pressure off the peroneal tendons.1,2
Dagan Cloutier, MPAS, PA-C, practices in a multispecialty orthopedic group in the southern New Hampshire region and is editor in chief of the Journal of Orthopedics for Physician Assistants.
1. Selmani E, Gjata V, Gjika E. Current concepts review: peroneal tendon disorders. Foot Ankle Int. 2006;27(3):221-228. doi:10.1177/107110070602700314
2. Philbin TM, Landis GS, Smith B. Peroneal tendon injuries. J Am Acad Orthop Surg. 2009;17(5):306-317. doi:10.5435/00124635-200905000-00005