What Are the Peroneal Tendons? For specialized treatment, see our peroneal tendon care at Balance Foot & Ankle.
The peroneal tendons—peroneus longus and peroneus brevis—run along the outer (lateral) side of the ankle, behind the lateral malleolus (the bony bump on the outside of the ankle), and attach to the foot. The peroneus brevis inserts at the base of the fifth metatarsal; the peroneus longus runs under the foot to the medial cuneiform and first metatarsal base. Together, these tendons evert the foot (turn it outward) and stabilize the ankle against inversion sprains. Peroneal tendon injuries are a common but frequently underdiagnosed cause of lateral ankle pain—often misdiagnosed as chronic ankle sprain.
Peroneal tendon problems fall into three main categories: tendinopathy (degenerative thickening and pain), longitudinal split tears (tearing along the length of the tendon, most commonly the peroneus brevis), and subluxation or dislocation (the tendons popping out of their groove behind the fibula due to superior peroneal retinaculum tear). Each requires a different treatment approach, and distinguishing between them requires MRI or ultrasound in addition to clinical examination.
Peroneal Tendon Tears
Longitudinal split tears of the peroneus brevis are the most common peroneal tendon injury. The peroneus brevis is compressed in the fibular groove during ankle inversion, causing it to split lengthwise rather than rupture completely. These tears produce lateral ankle pain behind the fibula, swelling along the tendon, and pain with resisted eversion. They frequently coexist with ankle ligament sprains, which is why they’re often missed initially. MRI or ultrasound demonstrates the split tear and its extent.
Conservative treatment (physical therapy, bracing, activity modification) is attempted for 3–6 months in partial tears. When conservative treatment fails or the tear is complete, surgical repair is indicated. Surgery involves exploring the tendon sheath, debridement of damaged tissue, and tubularization (suturing the split edges closed to restore tendon shape). If more than 50% of the tendon cross-section is involved, tenodesis to the peroneus longus (connecting the damaged tendon to the healthy one) may be performed. Peroneus longus tears are less common but occur at the cuboid tunnel and can cause lateral midfoot pain.
Peroneal Tendon Subluxation and Dislocation
Peroneal tendon subluxation occurs when the superior peroneal retinaculum—the fibrous band that holds the peroneal tendons in their groove behind the fibula—tears during a forceful ankle dorsiflexion-eversion injury. The tendons snap out of their groove (subluxate) and may dislocate anteriorly over the fibula. Patients feel and hear a snapping or popping sensation on the outer ankle with activity. This injury is common in skiers, football players, and basketball players.
Acute subluxation in young athletes is typically treated surgically to prevent recurrent dislocation. The retinaculum is repaired and reinforced, and sometimes the fibular groove is deepened (groove-deepening procedure) to better contain the tendons. Chronic or recurrent subluxation almost always requires surgical stabilization. Success rates with surgical repair are excellent—approximately 90–95% of patients return to sport without recurrent subluxation after appropriate repair.
Recovery After Peroneal Tendon Surgery
Recovery from peroneal tendon surgery depends on the procedure performed. Tendon repair (tubularization or tenodesis) requires 4–6 weeks non-weight-bearing in a boot or cast, followed by progressive weight-bearing through 8–10 weeks. Physical therapy begins with gentle range of motion and progresses to strengthening and proprioceptive training. Return to sport after isolated tendon repair typically occurs at 4–6 months.
Retinaculum repair for subluxation follows a similar timeline: 4–6 weeks non-weight-bearing, boot weaning by 10–12 weeks, and return to sport at 4–6 months. Groove-deepening procedures add complexity and may extend the timeline to 6–9 months. Physical therapy throughout recovery focuses on strengthening the peroneal muscles, restoring ankle proprioception (position sense), and sport-specific functional progression. Ankle taping or bracing is often used during the return-to-sport phase.
Frequently Asked Questions
How do I know if I have a peroneal tendon tear?
Peroneal tendon tears typically cause pain and tenderness directly behind the lateral malleolus (the outer ankle bone)—not at the ligament insertion slightly further forward. Pain is worse with activities requiring ankle stability (running, lateral movements, uneven terrain) and with resisted eversion (pushing the foot outward against resistance). Swelling along the tendon sheath behind the fibula is often present. If you’ve had multiple ankle sprains or have persistent lateral ankle pain beyond 6–8 weeks, MRI evaluation can diagnose peroneal tendon pathology. These injuries are commonly missed because the symptoms overlap significantly with lateral ankle ligament sprains.
Can a peroneal tendon tear heal without surgery?
Small partial peroneal tendon tears can sometimes stabilize with conservative treatment: 6–12 weeks of immobilization and physical therapy, followed by activity modification and bracing. Tendinopathy (degenerative thickening without complete tearing) often responds to physical therapy, eccentric strengthening exercises, and orthotics. However, longitudinal split tears—especially complete tears or those involving more than 50% of the tendon—have poor healing capacity without surgery and typically worsen over time without intervention. Peroneal subluxation in active patients almost always requires surgery, as the retinaculum cannot reliably heal with conservative treatment and recurrent subluxation causes progressive tendon damage.
What causes peroneal tendons to snap or pop on the outside of the ankle?
A snapping or popping sensation on the outer ankle during activity—especially with dorsiflexion (pulling the foot up) or eversion—is the hallmark of peroneal tendon subluxation. The tendons are slipping out of their groove behind the fibula as the retinaculum (the restraining band) is torn or loose. Some patients can voluntarily reproduce the snapping. This is distinct from the snapping sometimes felt at the ankle joint itself. Any reproducible tendon snapping on the outer ankle warrants evaluation—it typically indicates mechanical instability that will progress without treatment and commonly requires surgical retinaculum repair.
Medical References & Sources
- American Orthopaedic Foot & Ankle Society — Peroneal Tendon Injuries
- PubMed Research — Peroneal Tendon Repair Outcomes
- PubMed Research — Peroneal Subluxation Surgical Repair
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Dr. Tom Biernacki, DPM is a board-certified podiatric surgeon at Balance Foot & Ankle in Howell and Bloomfield Hills, Michigan. He diagnoses and treats peroneal tendon tears, subluxation, and tendinopathy with both conservative management and surgical repair.
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Our board-certified podiatrists treat this condition at two convenient locations. Same-day appointments often available.
Dr. Tom Biernacki, DPM is a board-qualified podiatrist and foot & ankle surgeon serving Southeast Michigan at Balance Foot & Ankle Specialists. A Michigan native, Dr. Biernacki earned his undergraduate degree from Michigan State University and his Doctor of Podiatric Medicine (DPM) from Kent State University College of Podiatric Medicine. He completed a three-year comprehensive surgical residency in foot and ankle surgery in the Detroit metro area.
Dr. Biernacki specializes in the treatment of heel pain, bunions, hammertoes, diabetic foot care, sports injuries, flatfoot correction, and minimally invasive foot surgery. He is dedicated to providing evidence-based, patient-centered care that helps people of all ages stay active and pain-free.
He sees patients at multiple convenient Metro Detroit locations and is committed to community education through the MichiganFootDoctors.com resource library. Dr. Biernacki is a member of the American Podiatric Medical Association (APMA) and the Michigan Podiatric Medical Association (MPMA).