Peroneus (Peroneal) Tendinopathy

Tendinopathy of the lateral ankle tendons, which act as dynamic stabilisers. Often mistaken for a lateral ankle sprain.

Two entities

  • Peroneus brevis: at the lateral malleolus, often with a longitudinal tear.
  • Peroneus longus: at the peroneal tubercle or os peroneum, linked to plantarflexion and first-ray loading.

Mechanism

  • Repetitive eversion and plantarflexion (overuse)
  • Acute inversion injury or chronic lateral ankle instability, a major predisposing factor
  • Subluxation or dislocation: superior peroneal retinaculum rupture after forced dorsiflexion-inversion
  • Cavovarus hindfoot increases peroneal loading
  • Sports: running (especially trail), basketball, football, tennis, skiing, dance

Risk factors

Anatomical Modifiable Systemic and drugs
Cavovarus or cavus foot, low-lying brevis muscle belly, peroneus quartus, os peroneum, shallow retromalleolar groove Poor ankle control, previous sprain, training errors Inflammatory arthropathy, diabetes, fluoroquinolones, corticosteroids

Presentation

  • Retrofibular pain (or lateral foot pain for longus), worse with resisted eversion, push-off and uneven ground
  • Swelling and tenderness along the tendon
  • Reduced eversion strength (compare sides). Assess hindfoot alignment.
  • Visible or palpable snapping on dorsiflexion-eversion indicates retinacular injury and tendon instability, not simple tendinopathy.
  • Persistent lateral pain after a “sprain” should raise suspicion.

Management

  1. Activity modification: first-line.
  2. Eccentric and progressive strengthening, plus proprioception: the cornerstone.
  3. Treat underlying ankle instability.
  4. Orthoses: lateral wedge or post for cavus or cavovarus feet.
  5. Short immobilisation for acute subluxation or severe pain.
  6. Shockwave, PRP: weak evidence.
  7. Surgery (retinaculum repair, groove deepening, tendon repair or reconstruction): confirmed subluxation, tears, or failed conservative care.

Practical warning

avoid corticosteroid injection into the peroneal tendons. Rupture risk is high and the functional consequences are severe. Some sources describe ultrasound-guided injection for refractory cases, but most consensus advises against it.

References

  1. van Dijk et al., ESSKA-AFAS consensus, KSSTA 2018, doi:10.1007/s00167-018-4971-x
  2. Peroneal tendon disorders, EFORT Open Rev 2017, doi:10.1302/2058-5241.2.160047
  3. Foot Ankle Spec 2021, doi:10.1177/1938640020916278

Medical disclaimer: this article is general information, not personal medical advice. Always consult a qualified doctor about your own situation.