What is the treatment for a lateral malleolus tip fracture?

Treatment of Lateral Malleolus Tip Fracture

Functional treatment with early mobilization using a lace-up ankle brace is the preferred approach for lateral malleolus tip avulsion fractures, avoiding immobilization and incorporating exercise therapy for optimal outcomes. 1

Initial Diagnostic Evaluation

• Obtain standard three-view ankle radiographs (anteroposterior, lateral, and mortise views) to assess the fracture fragment size and ankle alignment 1
• Apply Ottawa Ankle Rules to determine radiographic necessity: imaging is indicated if the patient has inability to bear weight immediately after injury, point tenderness over the lateral malleolus tip, or inability to ambulate 4 steps 2, 1
• Consider an anterior talofibular ligament view if the avulsion fragment is not clearly visible on standard radiographs 1

Determining Stability

The critical decision point is whether associated ligamentous injuries exist, particularly deltoid ligament disruption:

• Small tip avulsion fractures (<15mm) without medial clear space widening are typically stable and represent isolated anterior talofibular ligament avulsions 1, 3
• If medial clear space measures >4mm on standard or stress radiographs, this indicates deltoid ligament injury and ankle instability requiring surgical consideration 4, 5
• MRI can identify partial versus complete deltoid ligament tears when stress radiographs show 5-8mm medial clear space widening; partial tears can be managed nonoperatively while complete tears may require surgery 5

Conservative Treatment Protocol (Stable Fractures)

This is the treatment of choice for isolated lateral malleolus tip avulsions:

• Use a lace-up ankle brace rather than elastic bandage or tape, as it provides superior swelling reduction, fewer complications, and faster return to work 1
• Initiate early mobilization with weight-bearing as tolerated after 3-5 days of rest, ice, compression, and elevation 2
• Begin active exercise therapy early to prevent recurrent lateral ankle injuries and improve long-term outcomes 1
• Avoid prolonged immobilization, which delays return to work and daily activities compared to functional treatment 2

Surgical Indications (Unstable Fractures)

Surgery is reserved for specific scenarios:

• Large fragments (>15mm) that may compromise joint stability 3
• Confirmed complete deltoid ligament rupture on MRI with positive stress testing 5
• Medial clear space >4mm indicating ankle mortise instability 4

Follow-Up Monitoring

• Obtain serial radiographs to confirm proper healing and maintenance of alignment 1
• Use weight-bearing radiographs during follow-up to assess stability (medial clear space <4mm confirms stability) 3
• Monitor for complications, as 5-33% of patients experience persistent pain and instability at 1 year, and 3-34% develop recurrent ankle sprains 1

Critical Pitfalls to Avoid

• Do not miss associated deltoid ligament injuries, which convert a stable fracture into an unstable injury requiring different management 3, 5
• Avoid overly aggressive rehabilitation before adequate bony healing (typically 8 weeks), which can cause fragment displacement or nonunion 3
• Do not use prolonged immobilization for stable injuries, as functional treatment consistently demonstrates superior outcomes 2, 1
• Recognize that 70% of ankle fractures result in cartilage injury; persistent symptoms warrant MRI evaluation for osteochondral lesions 2