What are the symptoms and treatment options for peroneal tendinitis?

Peroneal Tendinitis Symptoms and Treatment

Peroneal tendinitis presents with lateral ankle pain, swelling, and potential instability, and should be treated with a combination of NSAIDs for short-term pain relief, activity modification, functional support with a brace for 4-6 weeks, and progressive rehabilitation focusing on eccentric strengthening exercises. 1

Symptoms of Peroneal Tendinitis

Peroneal tendinitis typically presents with:

• Lateral ankle pain (along the outside of the ankle)
• Swelling around the lateral malleolus
• Ankle instability 2
• Pain that worsens with activity and improves with rest
• Tenderness along the course of the peroneal tendons
• Pain with active eversion of the foot
• Potential "popping" or "clicking" sensation with ankle movement

Peroneal tendinopathy is often misdiagnosed, which can lead to chronic lateral ankle pain and instability 3. It should be suspected in any patient presenting with these symptoms, particularly when they persist despite treatment for lateral ankle sprains.

Diagnostic Evaluation

When peroneal tendinitis is suspected:

• Ultrasound (US) has shown 100% sensitivity and 90% accuracy in diagnosing peroneal tendon tears 4
• MRI can also be used with reported sensitivities and specificities of 83.9% and 74.5% for tendinopathy, and 54.5% and 88.7% for tendon tears 4
• US has the advantage of allowing dynamic assessment for tendon subluxation with a reported positive predictive value of 100% compared with surgical findings 4

Caution: MRI evidence of peroneal tendon pathology should be interpreted carefully as up to 34% of asymptomatic patients may have a tear of the peroneus brevis tendon 4

Treatment Approach

1. Pain Management

• NSAIDs are recommended for short-term pain relief 1
  • Ibuprofen 1.2g daily initially, can be increased to 2.4g daily
  • Naproxen 500mg twice daily is another option
  • Can be combined with paracetamol (up to 4g daily) for enhanced pain relief
  • Note: Prolonged use may interfere with natural healing 1

2. Activity Modification and Support

• Use a brace for functional support for 4-6 weeks rather than complete immobilization 1
• Reduce activities that cause pain
• Implement relative rest without complete immobilization
• Avoid flat shoes and barefoot walking 1

3. Rehabilitation Program

Follow a phased rehabilitation approach:

Phase	Focus	Duration
Initial	Pain control and protected range of motion	0-4 weeks
Intermediate	Progressive strengthening exercises and eccentric training	4-8 weeks
Advanced	Occupation-specific training and functional exercises	8-12 weeks

• Begin gentle ankle exercises as pain allows
• Focus on eccentric strengthening exercises, which have shown good evidence for tendinopathy treatment 1
• Include lateral calcaneal glide manual therapy technique, which has shown success in treating peroneal tendinopathy 5

4. Advanced Interventions

If conservative treatment fails after 6-8 weeks:

• Consider ultrasound-guided peroneal tendon sheath corticosteroid injection

  • Studies show 36.8% of patients experience pain relief for more than 12 weeks following injection 6
  • Low complication rate (1.8%) makes this a reasonable option before considering surgery 6
  • Caution: Shorter duration of symptom relief is associated with longer pre-injection symptom duration 6

• Surgical intervention should be considered if no improvement occurs after 3-6 months of well-managed conservative treatment 1

  • Approximately 25% of patients may eventually require surgery 6
  • Surgical options include debridement, tubularization, or in severe cases, resection of the damaged tendon and tenodesis 2

Return to Activity Criteria

Return to full activity is permitted when the patient demonstrates:

• Complete resolution of pain
• Full range of motion
• Strength symmetry >90% compared to the uninjured side
• Successful completion of occupation-specific functional tests 1

Common Pitfalls to Avoid

1. Misdiagnosis: Peroneal tendinopathy is often confused with lateral ankle ligament injuries 7
2. Overuse of corticosteroid injections: Limit to 2-3 injections with 4-6 weeks between injections 1
3. Prolonged immobilization: Avoid immobilization beyond 4 weeks as it can lead to muscle atrophy and worse outcomes 1
4. Inadequate rehabilitation: This increases the risk of chronic problems and recurrence 1
5. Delayed referral: Consider specialist referral if no improvement after 6-8 weeks of conservative treatment 1

Remember that peroneal tendinopathy is now understood as a degenerative process rather than an inflammatory one, which affects the approach to treatment 3.