- Peroneal tendinitis causes pain on the outer ankle due to inflammation of essential stabilizing tendons.
- Overloading activities, inadequate footwear, or chronic ankle instability often contribute to peroneal tendinitis.
- Addressing factors like uneven terrain, rapid movements, or foot structure is crucial for recovery.
- Persistent outer ankle pain, swelling, or clicking sounds warrant professional evaluation for proper diagnosis.
Table of Contents
- Anatomy
- Causes
- Mechanical Overload
- Chronic Ankle Instability
- Anatomical Anomalies
- Risk Factors
- Classification
- Tendinopathy (Tendinosis)
- Tenosynovitis
- Longitudinal Lesion
- Subluxation/Dislocation of the Peroneal Tendons
- Symptoms
- Warning Signs
- Diagnosis
- Clinical Examination
- Instrumental Exams
- Conservative Treatment
- Phase 1 — Pain Reduction (weeks 1-3)
- Phase 2 — Rehabilitation (weeks 3-8)
- Phase 3 — Return to Sport (weeks 8-12)
- Surgical Treatment
- Recovery Times
- Prevention
- Frequently Asked Questions (FAQ)
- Does peroneal tendinitis heal?
- How to distinguish peroneal tendinitis from a sprain?
- Can I run with peroneal tendinitis?
- Is an ankle brace useful?
- Related articles
Peroneal tendinitis
Peroneal tendinitis (peroneal tendinopathy) is an inflammation of the tendons of the peroneus longus and peroneus brevis muscles, located on the outer side of the ankle. These tendons are fundamental for the lateral stability of the ankle and for propulsion during walking and running. Peroneal tendinopathy is a frequent cause of lateral ankle pain, often underestimated or confused with chronic sprains. It predominantly affects athletes (runners, footballers, dancers) and people with chronic ankle instability.
Anatomy
There are two peroneal (or fibular) muscles:
- Peroneus longus: originates from the proximal third of the fibula; its tendon runs behind the lateral malleolus, passes under the foot, and inserts onto the base of the first metatarsal and the medial cuneiform. Function: foot eversion and stabilization of the first ray.
- Peroneus brevis: originates from the distal third of the fibula; its tendon runs behind the lateral malleolus and inserts onto the base of the fifth metatarsal. Function: foot eversion and plantarflexion.
Both tendons pass through a retro-malleolar groove (peroneal groove), held in place by the superior peroneal retinaculum. This point is the most frequent site of tendon pathology.
Causes
Mechanical Overload
- Sudden increase in training load (running, jumping)
- Uneven terrain: trail running, hiking on rough paths
- Repetitive eversion movements: running on inclined surfaces, changes of direction
- Inadequate footwear: shoes with poor lateral support
Chronic Ankle Instability
Chronic instability after repeated sprains is the most frequent cause of peroneal tendinopathy. Lateral ligamentous laxity forces the peroneals to work excessively as dynamic stabilizers.
Anatomical Anomalies
- Pes cavus or varus foot: increases stress on the peroneals due to hindfoot inversion
- Shallow retro-malleolar groove: predisposes to tendon subluxation
- Peroneus quartus: supernumerary muscle that reduces space in the peroneal canal
- Os peroneum: accessory bone in the peroneus longus tendon that can cause friction
Risk Factors
| Factor | Mechanism |
|---|---|
| Repeated ankle sprains | Instability → overload |
| Pes cavus/varus foot | Biomechanical stress |
| Trail running | Uneven terrain |
| Footballers, dancers | Rapid eversion movements |
| Rigid footwear (skiing, skating) | Direct pressure on the tendon |
Classification
Tendinopathy (Tendinosis)
Chronic degeneration of the tendon without a true acute inflammatory component. The tendon appears thickened, disorganized, with possible longitudinal fissures.
Tenosynovitis
Inflammation of the synovial sheath that covers the tendons as they pass retro-malleolarly. It manifests with swelling, crepitus, and pain.
Longitudinal Lesion
Fissure of the tendon along its course, more frequent in the peroneus brevis (which is “compressed” between the peroneus longus and the malleolus).
Subluxation/Dislocation of the Peroneal Tendons
The tendons slide over the lateral malleolus due to insufficiency of the retinaculum. This can occur acutely (after trauma) or be recurrent.
Symptoms
- Lateral ankle pain, behind and below the outer malleolus
- Swelling along the course of the tendons (retro-malleolar)
- Pain that worsens with activity, running, walking on uneven terrain
- Crepitus palpable along the tendons during movement
- Feeling of ankle instability
- Pain with resisted dorsiflexion and eversion of the foot
- In subluxation: a snapping sensation behind the malleolus during movements
Warning Signs
- Acute pain after a sprain that does not improve after 4-6 weeks
- Recurrent snapping behind the lateral malleolus
- Weakness in foot eversion
- Persistent lateral ankle swelling
Diagnosis
Clinical Examination
- Palpation: pain along the course of the peroneal tendons, from the retro-malleolar area to the base of the fifth metatarsal
- Resisted eversion: pain and/or weakness
- Subluxation test: active dorsiflexion and eversion against resistance, looking for retro-malleolar snapping
- Single leg heel raise in eversion test: evaluates peroneal function
- Assessment of ligamentous stability: anterior drawer and talar tilt
Instrumental Exams
- Ultrasound: first instrumental exam, visualizes the tendon (thickening, fissures, fluid in the sheath), dynamic assessment of subluxation
- Magnetic Resonance Imaging (MRI): gold standard for longitudinal fissures, tendinosis, associated lesions
- X-ray: excludes fractures, os peroneum, calcifications
Conservative Treatment
Anatomy is the study of human body structures, including bones, muscles, tendons, and ligaments, and their spatial relationships and functions. Effective in 70-80% of tendinopathy cases without structural lesions.
Phase 1 — Pain Reduction (weeks 1-3)
- Temporary reduction of provocative activities
- Cryotherapy: 15-20 minutes, 3-4 times a day
- Topical NSAIDs on the retro-malleolar region
- Ankle brace or taping to stabilize and reduce stress on the peroneals
- Footwear with good lateral support
Phase 2 — Rehabilitation (weeks 3-8)
Eccentric peroneal exercises:
- Seated, foot on the edge of a step. Start in eversion and slowly lower into inversion (eccentric phase). 3 sets of 15, once a day.
Isometric and concentric strengthening:
- Eversion against elastic resistance: 15 repetitions, 3 sets
- Inversion against resistance: 15 repetitions (posterior tibialis strengthening for balance)
- Dorsiflexion and plantarflexion with elastic band
Proprioception and stability:
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- Single leg stance: 30 seconds, 3 repetitions per side. Progression: eyes closed, unstable surface
- Proprioception on a wobble board
- Single leg squat with focus on ankle stability
Stretching:
- Calf stretch (gastrocnemius and soleus)
- Peroneal stretch: gentle foot inversion held for 30 seconds
Instrumental therapy:
- Pulsed therapeutic ultrasound
- High-power laser therapy
- Focused shockwave therapy (in chronic resistant tendinopathy)
Phase 3 — Return to Sport (weeks 8-12)
- Progressive running on flat surfaces
- Gradual introduction of uneven terrain
- Plyometric exercises: controlled jumps, single leg landings
- Agility drills: changes of direction, shuttle runs
- Taping or brace during return to sport
Surgical Treatment
Indicated in 20-30% of cases that do not respond to 3-6 months of conservative treatment.
- Debridement and synovectomy: cleaning of the tendon and sheath
- Repair of longitudinal lesion: tubular suture of the tendon
- Deepening of the retro-malleolar groove: in case of a flat groove predisposing to subluxation
- Retinaculum reconstruction: for recurrent subluxation
- Tenodesis: in extensive lesions of the peroneus brevis, with transfer to the peroneus longus
Recovery Times
| Treatment | Daily Activities | Sport |
|---|---|---|
| Conservative | 3-4 weeks | 8-12 weeks |
| Post-debridement | 4-6 weeks | 3-4 months |
| Post-retinaculum reconstruction | 6-8 weeks | 4-6 months |
Prevention
- Proprioception: single-leg balance exercises after every sprain
- Strengthening of the peroneals and posterior tibialis: lateral ankle muscle balance
- Appropriate footwear: with good lateral support for the terrain practiced
- Warm-up: before activity on uneven terrain
- Treatment of sprains: complete rehabilitation, not just rest
- Preventive taping: during high-risk sports activity
Frequently Asked Questions (FAQ)
Yes, in the majority of cases, peroneal tendinopathy heals with conservative treatment. Recovery requires consistency in rehabilitation and a gradual return to activity. Chronic forms with structural lesions may require surgical treatment with good results.
A sprain causes acute pain, immediate swelling, and instability after an inversion trauma. Peroneal tendinopathy has a gradual onset, with retro-malleolar pain that worsens with activity. Often, the two conditions coexist: instability from a sprain causes overload of the peroneals.
In acute painful phases, it is advisable to reduce or suspend running. After initial improvement, you can gradually resume on flat surfaces with appropriate footwear and taping. Trail running should be reintroduced last. Pain is the guide: if pain is less than 3/10 during and after running, the load is acceptable.
An ankle brace or taping can be useful in the acute phase to reduce stress on the tendons and in the return-to-sport phase as protection. However, they should not replace rehabilitation: the peroneal muscles must be strengthened to ensure lasting ankle stability.
Frequently Asked Questions
Does peroneal tendinitis heal?
Peroneal tendinitis typically responds well to conservative treatment when addressed promptly. Full recovery often involves a structured rehabilitation program focusing on pain reduction, strengthening, and gradual return to activity. Adherence to a physical therapist’s guidance is crucial for optimal healing and preventing recurrence.
How to distinguish peroneal tendinitis from an ankle sprain?
Peroneal tendinitis often presents with gradual onset of pain along the outer ankle, which may worsen with activity. An ankle sprain, conversely, typically results from a sudden traumatic event, causing immediate pain, swelling, and instability. A thorough clinical examination by a healthcare professional is essential to accurately differentiate between these conditions.
Can I run with peroneal tendinitis?
Running with peroneal tendinitis is generally not recommended as it can exacerbate inflammation and delay healing. Activities that provoke pain should be modified or temporarily avoided to allow the tendons to recover. A physical therapist can guide a safe return-to-running progression once symptoms have subsided and strength is restored.
Is an ankle brace useful for peroneal tendinitis?
An ankle brace can provide temporary support and reduce stress on the peroneal tendons during the initial phases of recovery. However, it should be used as part of a comprehensive treatment plan, not as a standalone solution. A physical therapist can advise on the appropriate type and duration of brace use, alongside exercises to improve ankle stability.
Sources and Scientific References
- Karlsson J et al. (1992). Lateral instability of the ankle joint. Clin Orthop Relat Res.:253-61. PubMed
- Gougoulias N et al. (2014). Taking out the tarsal coalition was easy: but now the foot is even flatter. What now? Foot Ankle Clin. 19:555-68. DOI | PubMed
- Federer AE et al. (2015). Blastomyces Tenosynovitis of the Foot and Ankle: A Case Report and Review of the Literature. J Foot Ankle Surg. 54:1183-7. DOI | PubMed
- Lotito G et al. (2011). Peroneus quartus and functional ankle instability. Ann Phys Rehabil Med. 54:282-92. DOI | PubMed
- Hudson PW et al. (2019). Preoperative Assessment of the Peroneal Tendons in Lateral Ankle Instability: Examining Clinical Factors, Magnetic Resonance Imaging Sensitivity, and Their Relationship. J Foot Ankle Surg. 58:208-212. DOI | PubMed