What is the treatment for an avulsion fracture of the tip of the medial malleolus?

Treatment for Avulsion Fracture of the Tip of Medial Malleolus

Conservative treatment with immobilization in a cast is the recommended approach for isolated avulsion fractures of the tip of the medial malleolus, as these fractures can achieve high rates of union and good functional results without surgical intervention. 1

Initial Evaluation

• Initial assessment should include standard three-view ankle radiographs (anteroposterior, lateral, and mortise views) to evaluate the fracture fragment and overall ankle alignment 2
• Radiographs are indicated in patients who meet Ottawa Ankle Rules criteria as the initial imaging study 2
• CT scan may be necessary to determine the exact extent, displacement, and any intra-articular extension of the fragment in complex cases 2

Treatment Algorithm

Conservative Management (Primary Recommendation)

• For isolated avulsion fractures of the tip of the medial malleolus:
  • Immobilization in a cast for 6-8 weeks 1
  • Non-weight bearing initially, progressing to partial weight bearing as healing progresses 1
  • Regular radiographic follow-up to confirm healing 2

Surgical Management (Secondary Recommendation)

• Surgery should be reserved for specific circumstances:
  • Bi- or trimalleolar fractures 1
  • Open fractures 1, 3
  • Injuries which compromise the skin 1
  • Fractures involving the ankle joint surface (plafond) 1
  • Patients who develop painful nonunion 1
  • Large fragments (>15mm) that may affect joint stability 4
  • Cases with deltoid ligament involvement causing ankle instability 5, 6

Post-Treatment Management

• Progressive weight bearing after adequate healing is confirmed radiographically 1
• Physical therapy to restore range of motion and strength 1
• Weight-bearing radiographs during follow-up to assess stability (medial clear space <4mm confirms stability) 4

Expected Outcomes

• High union rates (55 out of 57 fractures healed without further treatment in one study) 1
• Good functional outcomes with conservative treatment 1
• Mean American Orthopaedic Foot and Ankle Society scores of 89.8 (range 69 to 100) 1
• No evidence of medial instability, skin complications, malalignment of the mortise, or post-traumatic arthritis with proper conservative management 1

Special Considerations

• In cases with deltoid ligament involvement, repair may be necessary to prevent persistent medial instability 5, 6
• Novel approaches for unstable open medial malleolar fractures may include minimally invasive fixation of associated fractures (e.g., fibula) while leaving the medial malleolus without fixation in select cases 3
• In high-performance athletes, more aggressive treatment with surgical fixation may be considered to facilitate earlier return to activity 6

Pitfalls to Avoid

• Failure to recognize associated ligamentous injuries can compromise outcomes 4, 6
• Overly aggressive rehabilitation before adequate healing can lead to displacement or nonunion 4
• Inadequate radiographic evaluation may miss subtle fracture patterns or associated injuries 2