How should a patient with a full-thickness tear in the peroneus brevis and tendinosis in the peroneus longus be managed?

Management of Full-Thickness Peroneus Brevis Tear with Peroneus Longus Tendinosis

Surgical repair of the peroneus brevis tendon combined with treatment of the peroneus longus tendinosis is strongly recommended to restore ankle stability, prevent progressive deformity, and improve functional outcomes.

Diagnostic Confirmation

MRI is the preferred imaging modality for confirming peroneal tendon pathology with high sensitivity (>90%) for diagnosing ankle tendon tears 1. However, clinical correlation is essential as MRI evidence of peroneal tendon pathology has only a 48% positive predictive value for clinical findings 1.

Key diagnostic findings include:

• Longitudinal split tear in peroneus brevis (full thickness)
• Hyperemia and adjacent fluid in peroneus longus suggesting tendinosis
• Possible lateral ankle instability (commonly associated)

Treatment Algorithm

1. Initial Management

• Surgical intervention is indicated due to the full-thickness tear of peroneus brevis
• Conservative management is unlikely to be successful for full-thickness tears
• Delay in surgical treatment may lead to:
  • Progressive tendon degeneration
  • Worsening lateral ankle instability
  • Development of hindfoot varus deformity

2. Surgical Approach

For the peroneus brevis tear:

• Débridement and tubularization for less extensive tears
• Resection of damaged tendon segments with tenodesis to peroneus longus for more severe cases 2
• Reconstruction using autograft (semitendinosus/gracilis tendons) may be necessary in cases of extensive damage 3

For the peroneus longus tendinosis:

• Tenosynovectomy to address inflammation
• Débridement of degenerative tissue
• Assessment and repair of any partial tears

3. Addressing Associated Conditions

• Evaluate and repair lateral ankle ligaments if instability is present
• Reconstruct the superior peroneal retinaculum if damaged 4
• Assess for and address anatomical contributors:
  • Enlarged peroneal tubercle
  • Sharp posterior ridge of the fibula
  • Shallow peroneal groove

Rehabilitation Protocol

Phase 1 (0-4 weeks):

• Non-weight bearing with cast or boot immobilization
• Pain control and protected range of motion exercises 5

Phase 2 (4-8 weeks):

• Progressive weight bearing
• Initiation of strengthening exercises
• Proprioceptive training 5

Phase 3 (8-12 weeks):

• Sport-specific or occupation-specific training
• Progressive return to full activities 5

Expected Outcomes

With appropriate surgical management and rehabilitation:

• 91% of patients achieve normal or moderate peroneal muscle strength 6
• Mean AOFAS ankle score of 82 points can be expected 6
• Most patients can return to pre-injury activity levels within 5-6 months 3

Important Considerations

1. Concomitant pathologies: Peroneal tendon tears are frequently associated with lateral ankle instability and should be addressed simultaneously 4, 6.

2. Anatomical variants: Hindfoot varus, an enlarged peroneal tubercle, or a shallow peroneal groove may contribute to tendon pathology and should be evaluated 7.

3. Delayed diagnosis: Peroneal tears are often misdiagnosed due to vague lateral ankle pain, leading to chronic conditions that are more difficult to treat 2.

4. Rehabilitation compliance: Adherence to a structured rehabilitation program is crucial for optimal outcomes and prevention of re-injury.

5. Return to activity criteria: Complete resolution of pain, full range of motion, strength symmetry >90% compared to the uninjured side, and successful completion of sport-specific functional tests 5.

By addressing both the peroneus brevis tear and peroneus longus tendinosis with appropriate surgical techniques and comprehensive rehabilitation, patients can expect significant improvement in function and return to pre-injury activities.