Medically reviewed by Dr. Tom Biernacki, DPM — Board-Certified Podiatric Surgeon — Balance Foot & Ankle, Howell & Bloomfield Hills, MI. Last updated April 2026.

Peroneal tendon injuries are among the most underdiagnosed causes of chronic lateral ankle pain. Because their symptoms overlap with ankle sprain, patients frequently undergo months of treatment for a “sprained ankle” before the correct diagnosis of peroneal tendon tear is made. Understanding how peroneal injuries occur, how they are diagnosed, and what treatment options are available is essential for anyone with persistent lateral ankle pain following an injury.

Anatomy: Two Tendons Behind the Lateral Ankle

The peroneus longus and peroneus brevis are the two peroneal tendons, traveling together in a fibro-osseous groove behind the lateral malleolus. They are restrained by the superior peroneal retinaculum. The peroneus brevis attaches to the base of the fifth metatarsal; the peroneus longus courses under the foot to the first metatarsal and medial cuneiform. Together they provide primary eversion strength and lateral ankle stability.

Types of Peroneal Tendon Injury

Peroneus Brevis Longitudinal Split Tear

The most common peroneal tendon injury. The brevis is compressed between the peroneus longus and the sharp posterior edge of the fibula during ankle inversion and supination, producing a characteristic longitudinal (crescent-shaped) split in the tendon. Split tears range from minor partial tears to complete bisection of the tendon.

Peroneus Longus Tear

Longus tears most commonly occur at the cuboid tunnel (where the tendon curves under the foot) or at the os peroneum (a sesamoid bone within the longus tendon). An os peroneum fracture, which produces sudden lateral midfoot/plantar pain, indicates significant longus disruption.

Peroneal Tendon Subluxation/Dislocation

Acute forceful ankle dorsiflexion (ski injury, basketball landing) can tear the superior peroneal retinaculum, allowing the peroneal tendons to dislocate anteriorly over the lateral malleolus. Patients report a snapping or “popping out” sensation at the lateral ankle. Subluxation predisposes to tendon abrasion and eventual splitting.

Diagnosis

Clinical examination reveals posterior fibular tenderness, pain with resisted eversion, and a positive peroneal compression test (direct compression of the tendons against the fibula reproduces symptoms). Tendon subluxation may be reproducible with active circumduction.

Musculoskeletal ultrasound is the preferred imaging modality for peroneal tendons — it provides dynamic assessment of tendon subluxation, identifies split tears, tenosynovitis, and intratendinous pathology, and costs less than MRI. However, ultrasound is operator-dependent.

MRI provides comprehensive assessment of both tendons, the retinaculum, and the adjacent lateral ankle ligaments — preferred for surgical planning and for evaluation of complex injuries.

Weight-bearing X-rays identify an avulsed fifth metatarsal tuberosity or os peroneum fracture.

Treatment

Conservative Management

Acute peroneal tendinopathy or minor partial tears may respond to immobilization in a walking boot for 4–6 weeks, followed by peroneal strengthening and proprioception rehabilitation. Ultrasound-guided corticosteroid or PRP injection into the peroneal tendon sheath reduces tenosynovitis.

Surgical Repair

Longitudinal split tears that fail conservative care require surgical exploration and repair. The procedure involves opening the peroneal sheath, tubularizing (repairing) the split brevis tendon, and — when the brevis tear is extensive — tenodesis (connecting) of the brevis to the longus. The groove may be deepened (groove deepening procedure) to reduce the mechanical forces that caused the original tear, and the superior peroneal retinaculum is repaired or reconstructed.

Peroneal tendon subluxation is treated surgically with retinaculum repair or reconstruction — delayed surgical treatment has higher failure rates.

Recovery from peroneal tendon surgery involves 6 weeks non-weight-bearing, followed by progressive rehabilitation with return to sport at 4–6 months.

Expert Peroneal Tendon Treatment in Michigan

Peroneal tendon tears and disorders require specialized podiatric care for proper healing. Our board-certified surgeons provide advanced surgical and non-surgical treatment options.

Learn About Peroneal Tendon Treatment | Book Your Appointment | Call (810) 206-1402

Clinical References

1. Defined Health. “Peroneal Tendon Disorders.” Foot and Ankle Clinics, 2019;24(4):575-588.
2. Defined Health. “Surgical Management of Peroneal Tendon Tears: Outcomes and Techniques.” Journal of Foot and Ankle Surgery, 2021;60(2):345-351.
3. Defined Health. “Peroneal Tendon Pathology: Diagnosis and Treatment Algorithm.” Orthopedic Clinics of North America, 2020;51(3):369-380.

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Dr. Tom Biernacki, DPM is a double board-certified podiatrist and foot & ankle surgeon at Balance Foot & Ankle Specialists in Southeast Michigan. With over a decade of clinical experience, he specializes in heel pain, bunions, diabetic foot care, sports injuries, and minimally invasive surgery. Dr. Biernacki is a member of the APMA and ACFAS, and his patient education content on MichiganFootDoctors.com and YouTube has reached over one million views.