What is the recommended treatment for peroneus brevis tendonosis with a low-lying peroneus muscle and a long interstitial tear?

Treatment for Peroneus Brevis Tendonosis with Low-Lying Muscle and Interstitial Tear

Surgical repair is the standard of care for peroneus brevis tendon tears, especially with a long interstitial tear below the retromalleolar groove, as conservative measures often fail to provide adequate relief for this specific condition. 1

Diagnostic Considerations

Before initiating treatment, proper diagnosis is essential:

• MRI is highly effective for diagnosing peroneal tendon pathology with sensitivities of 83.9% for tendinopathy and 54.5% for tendon tears 2
• Ultrasound is also valuable with reported 100% sensitivity and 90% accuracy in diagnosing peroneal tendon tears 2
• Key clinical signs include:
  • Swelling along the peroneal tendon sheath
  • Pain with eversion
  • Possible tendon subluxation 1

Treatment Algorithm

1. Initial Conservative Management (4-6 weeks)

• Bracing: Preferable to taping due to practical usability and cost considerations 2
• NSAIDs: First-line medication for pain and inflammation control 3
• Physical therapy: Focus on:
  • Proprioception exercises
  • Strength training (particularly eversion)
  • Coordination exercises 2
• Activity modification: Immediate functional treatment with pain-free walking as tolerated 3

2. Advanced Conservative Options (if initial treatment fails)

• Ultrasound-guided peroneal tendon sheath corticosteroid injection:
  • Relatively safe with only 1.8% complication rate
  • Provides variable relief: 36.8% of patients experience >12 weeks of pain relief
  • 25% of patients ultimately require surgery despite injection 4

3. Surgical Management (recommended for this specific case)

Surgical approach depends on the extent of tendon damage:

• For tears involving <50% of cross-sectional area:

  • Débridement and tubularization of the tendon 1, 5

• For tears involving >50% of cross-sectional area (likely in this case with "long interstitial tear"):

  • Resection of the damaged tendon segment
  • Tenodesis of proximal and distal segments to the peroneus longus 1, 5

• Additional procedures to address contributing factors:

  • Stabilization of any tendon subluxation
  • Correction of the low-lying muscle belly if contributing to overcrowding in the retromalleolar groove 5

Recovery Expectations

• Return to maximum activity is prolonged but with proper treatment, good to excellent results can be expected 1
• Average postoperative AOFAS score of 85 reported in clinical studies 5
• Rehabilitation should include:
  • Proprioception training
  • Strength exercises
  • Coordination and functional training 2

Important Considerations and Pitfalls

1. Misdiagnosis risk: Peroneal tears are frequently misdiagnosed due to vague lateral ankle pain 1

2. Associated conditions: Check for concurrent lateral ankle instability, as chronic ankle laxity may contribute to peroneus brevis tears 6

3. Surgical timing: Don't delay surgical intervention excessively, as longer duration of symptoms correlates with poorer response to conservative treatment 4

4. Anatomical factors: The presence of a low-lying muscle belly (as in this case) may contribute to overcrowding in the peroneal groove, increasing tear risk and potentially complicating recovery 1

5. Post-surgical rehabilitation: Critical for optimal outcomes, should focus on proprioception, strength, coordination, and function of the extremity 2