Two tendons run in a shared groove behind the outer ankle bone (the lateral malleolus): the peroneus longus and the peroneus brevis. Both evert (turn outward) and plantarflex the foot, but they have distinct paths and insertions. The peroneus brevis inserts at the base of the fifth metatarsal; the peroneus longus crosses under the foot to the first metatarsal base and medial cuneiform. Both are held in their groove by the superior peroneal retinaculum, a band of tissue behind the fibula.
Three distinct injury patterns affect the peroneal tendons, each with different symptoms, risk factors, and management:
| Injury Type | What Happens | Classic Presentation | Key Risk Factors |
| Peroneal tendinopathy (tendinitis / tendinosis) | Inflammation (tendinitis) or chronic degeneration (tendinosis) of one or both peroneal tendons. Most common peroneal tendon condition. | Aching along the outer ankle and lower leg, worse with activity and after prolonged standing. Gradual onset, often bilateral. | Overuse, training load increase, high-arched foot, poor footwear, prior ankle sprain. |
| Peroneal tendon tear (longitudinal split tear) | The peroneus brevis is most commonly torn — it splits longitudinally around the posterior fibula margin. Can be partial or complete. | Persistent lateral ankle pain after a sprain or forced inversion. Often misdiagnosed as chronic ankle sprain. May have a palpable defect. | Acute inversion injury, chronic ankle instability, high-arched foot, peroneal tubercle hypertrophy, low-lying muscle belly. |
| Peroneal tendon subluxation / dislocation | The superior peroneal retinaculum tears or avulses, allowing the tendons to snap forward over the fibula during ankle motion. | Snapping or popping sensation at the back of the outer ankle, especially with dorsiflexion. Acute onset, often after a forced dorsiflexion injury (skiing, snowboarding). | Forced dorsiflexion mechanism, shallow fibular groove, prior ankle sprain, high athletic demand. |
Diagnosis
Clinical examination starts with palpating the peroneal tendons along their course. A positive peroneal compression test (pain with resisted eversion) and provocation of the snapping with active circumduction help identify the injury type. We also assess ankle stability, since chronic instability and peroneal tendon pathology commonly coexist.
- X-ray — identifies a fleck sign (small avulsion fracture fragment) associated with retinaculum tears, peroneal tubercle hypertrophy, or fifth metatarsal base fracture that can accompany peroneal injury.
- Diagnostic ultrasound — May be performed in-office. Can help identify tendinopathy, longitudinal tears, tenosynovitis, and dynamic subluxation in real time during ankle movement.
- MRI — provides the most complete picture of tear extent, retinaculum integrity, and any associated bony abnormalities. Used for surgical planning or when the diagnosis is unclear.
The most commonly missed diagnosis: a peroneus brevis longitudinal split tear in a patient treated for chronic ankle instability. If you have been told you have a sprained ankle that is not healing, have had repeated ankle sprains, or have persistent outer ankle pain after an inversion injury, peroneal tendon involvement should be specifically evaluated — it will not show on a standard ankle ligament examination without targeted tendon assessment.
Treatment at Family Foot & Ankle Clinic
Treatment depends on the injury type and severity. Tendinopathy responds well to conservative care. Significant tears and retinaculum disruption causing true subluxation often require surgical management.
Conservative Management
Activity modification and immobilization. For acute tendinopathy or a partial tear in the acute phase, reducing the aggravating activity and temporary immobilization in a walking boot allows inflammation to settle and the tendon to begin healing.
Structured rehabilitation. Progressive loading of the peroneal tendons — starting with resisted eversion and advancing to eccentric loading and balance training — is the cornerstone of tendinopathy treatment. Our Lateral Ankle Sprain Rehabilitation Program includes the resisted eversion, single-leg balance, and proprioception exercises that are directly applicable to peroneal tendon rehabilitation, plus bracing guidance and return-to-activity criteria. See the download below.
Custom orthotics. For patients with a high-arched foot or chronic ankle instability contributing to peroneal overload, a custom orthotic with lateral wedging reduces the varus stress on the peroneal tendons with every step. More on our Custom Orthotics page.
Ankle bracing. A functional ankle brace reduces the inversion stress on the peroneal tendons during activity and is particularly useful for patients with concurrent chronic ankle instability.
Shockwave Therapy (EPAT) for Chronic Tendinopathy
Shockwave therapy (EPAT). For peroneal tendinopathy that has not responded to conservative care, shockwave therapy targets the chronically thickened and degenerated tendon tissue directly — stimulating healing rather than masking pain. The same evidence base that supports shockwave for Achilles tendinopathy applies to peroneal tendinopathy, with good clinical outcomes reported for chronic, recalcitrant cases. Non-invasive, in-office, no downtime, typically six sessions. Offered as a cash-pay service with package pricing available. → See our Shockwave Therapy (EPAT) page.
Surgical Management
Surgery is considered for:
- Significant longitudinal tears of the peroneus brevis that have not responded to conservative management — tubularization (repair and reshaping of the split tendon) or, for severe tears, transfer to the peroneus longus
- Peroneal tendon subluxation with confirmed retinaculum disruption — retinaculum repair or fibular groove deepening procedure
- Complete peroneal tendon rupture requiring reconstruction
- Tendinopathy with a structural contributing factor (peroneal tubercle hypertrophy) requiring bony decompression
See our Foot & Ankle Surgery Overview for general information on surgical care at our clinic.
Frequently Asked Questions
How do I know if it’s a peroneal tendon injury or an ankle sprain?
The location of tenderness is the key distinction. Ligament sprains produce tenderness at the ATFL (front of the outer ankle bone) or CFL (below it). Peroneal tendon injuries produce tenderness behind and below the outer ankle bone, along the groove where the tendons run. Both can hurt in the same general area, which is why injuries involving both structures are frequently missed. If your ankle sprain pain is behind the outer ankle bone rather than in front of or below it, the peroneal tendons should be specifically examined.
Can a peroneal tendon tear heal on its own?
Partial tears can improve significantly with structured conservative management — activity modification, immobilization, progressive loading, and orthotics. Complete tears and large longitudinal split tears typically do not heal adequately without surgery. The key variable is size and chronicity: small partial tears identified early respond well to conservative care; large tears identified after months or years of continued loading are more difficult to repair.
Why does my ankle pop or snap when I move it?
A snapping sensation at the back of the outer ankle with ankle movement is the defining symptom of peroneal tendon subluxation. The tendons are slipping in and out of their groove behind the fibula because the retinaculum holding them in place has been torn. This is distinct from the general clicking many ankles produce. True tendon subluxation does not improve with rest alone and typically requires surgical retinaculum repair for definitive resolution.
I’ve been told I have chronic ankle instability. Could it be my peroneal tendons?
Possibly both. Chronic ankle instability and peroneal tendon tears frequently coexist — the same inversion mechanism that damages the lateral ligaments also loads the peroneal tendons. Studies suggest peroneus brevis tears are present in a significant proportion of patients with chronic ankle instability who undergo surgery. If your “ankle instability” includes persistent pain behind the fibula and does not improve with ligament-focused rehabilitation, the tendons should be specifically evaluated. Our Second Opinion / Foot Pain Not Improving visit is a useful starting point.
Outer Ankle Pain After a Sprain That Hasn’t Healed? Get It Properly Evaluated.
Peroneal tendon injuries that are identified early and treated correctly resolve well. Those that are missed and managed as simple sprains for months tend to progress to structural damage that is harder to repair. Book an appointment at our Coon Rapids or Golden Valley office and we will examine both the ligaments and the tendons, get the right imaging, and tell you exactly what is going on.
Call 763-421-7300 | Book online
Serving Coon Rapids, Golden Valley, Maple Grove, Champlin, Blaine, Plymouth, Andover, Wayzata, Minnetonka, Edina, and all Twin Cities communities.
Related Services & Conditions
- Ankle Sprains & Chronic Instability
- Shockwave Therapy (EPAT)
- Custom Orthotics
- Haglund’s Deformity
- Foot & Ankle Surgery Overview
- Second Opinion / Foot Pain Not Improving