What is the management for peroneal tendonitis on the lateral aspect of the foot?

Management of Peroneal Tendonitis on the Lateral Aspect of the Foot

Conservative management with activity modification, eccentric strengthening exercises, and orthotic correction should be the initial treatment approach for peroneal tendonitis, with immobilization reserved for refractory cases and surgery considered only after 2-3 months of failed conservative therapy. 1

Initial Conservative Treatment (First 6-8 Weeks)

The foundation of peroneal tendonitis management mirrors evidence-based tendinopathy protocols:

• Eccentric strength training is the most effective conservative intervention, promoting tendon healing and reducing symptoms 1
• Deep transverse friction massage of the peroneal tendons reduces pain and facilitates tissue remodeling 1
• Activity modification by reducing repetitive loading activities that stress the lateral ankle 1
• NSAIDs for acute pain control, though they do not alter long-term outcomes 1
• Orthotic correction to address anatomic misalignment, particularly forefoot varus, heel varus, excessive pes planus, or foot overpronation that increases peroneal tendon stress 1

Anatomic Considerations and Differential Diagnosis

When evaluating lateral foot pain, you must distinguish peroneal tendonitis from other pathology:

• Peroneus brevis longitudinal tears occur when the tendon rides over the sharp posterior fibular edge, causing retromalleolar pain with ankle instability 2, 3
• Peroneal tendon subluxation presents with dynamic instability and requires ultrasound for diagnosis (100% positive predictive value compared to surgical findings) 4
• Concomitant lateral ankle ligament injuries frequently coexist with peroneal pathology and share similar injury mechanisms 2
• Os peroneum pathology should be considered in the differential 5

Advanced Imaging When Indicated

If symptoms persist beyond 2-3 weeks or clinical examination suggests structural pathology:

• Ultrasound is the preferred initial imaging modality for dynamic assessment of tendon subluxation (100% PPV) and has demonstrated 100% sensitivity and 90% accuracy for diagnosing peroneal tendon tears 4, 5
• MRI achieves >90% sensitivity for ankle tendon tears but only 66% accuracy for subluxation assessment compared to ultrasound 5

Refractory Cases (6-8 Weeks Without Improvement)

When initial conservative measures fail:

• Immobilization with a cast or fixed-ankle walker-type device for 2-3 months while continuing other conservative treatments 1
• Ultrasound-guided corticosteroid injection into the peroneal tendon sheath provides >12 weeks of pain relief in 36.8% of patients, with complications occurring in only 1.8% of cases 6
• Manual therapy techniques, specifically lateral calcaneal glides combined with talocrural joint mobilization, have shown benefit when standard approaches fail 7

Surgical Referral Indications

Refer to a foot and ankle surgeon when:

• No improvement after 2-3 months of comprehensive conservative management including immobilization 1
• Structural pathology identified on imaging (longitudinal tears, subluxation, complete tears) 2, 3
• Concomitant lateral ankle instability requiring ligament reconstruction 2

Surgical options include debridement, tubularization for partial tears, side-to-side tendon repair, superior peroneal retinaculum reconstruction, or tenodesis in severe cases 2, 3, 8.

Post-Treatment Rehabilitation

Following either conservative treatment or surgery:

• Structured proprioceptive training is essential for return to function 4
• Coordination exercises and functional activities under supervision facilitate faster recovery 4
• Gradual return to activities based on functional recovery rather than arbitrary timeframes 4

Critical Pitfalls to Avoid

• Do not inject corticosteroids directly into the tendon substance—only peritendinous sheath injections are appropriate 6
• Do not overlook concomitant lateral ankle ligament injuries, as they require simultaneous surgical repair when present 2
• Do not rely solely on MRI for subluxation assessment—ultrasound is superior for this specific pathology 4, 5
• Preinjection symptom duration correlates with treatment response—longer symptom duration predicts shorter pain relief from injections 6