Treatment of Nondisplaced Lateral Malleolus Fracture
For a nondisplaced lateral malleolus fracture, initiate conservative treatment with functional mobilization using a lace-up ankle brace and early weight-bearing in a short-leg walking cast, provided the fracture is confirmed stable on weight-bearing radiographs with a medial clear space <4 mm. 1, 2
Initial Imaging and Stability Assessment
Obtain standard three-view ankle radiographs (anteroposterior, lateral, and mortise views) to confirm the fracture is truly nondisplaced and assess overall ankle alignment 1, 2
Weight-bearing radiographs are critical to determine stability—the single most important criterion guiding treatment decisions 1, 3
A medial clear space <4 mm on weight-bearing views confirms fracture stability and supports conservative management 1, 3
Assess for signs of instability including medial tenderness, bruising, swelling, or fibular fracture above the syndesmosis, which would indicate associated ligamentous injury requiring different management 1
Conservative Treatment Protocol
Functional treatment with early mobilization is superior to rigid immobilization for nondisplaced lateral malleolus fractures, resulting in faster return to work, better patient satisfaction, and quicker return to sports. 2
Apply a lace-up ankle brace rather than elastic bandage or tape, as it provides better swelling reduction, fewer complications, and faster functional recovery 2
Allow protected weight-bearing in a short-leg walking cast for stable, isolated lateral malleolus fractures 4
Incorporate exercise therapy into the treatment plan to prevent recurrence and improve long-term outcomes 2
Follow-Up and Monitoring
Obtain serial radiographs to confirm maintenance of alignment and assess healing progression 3, 2
Monitor for delayed union or nonunion, though this is rare in nondisplaced fractures treated conservatively 5, 6
Continue follow-up until radiographic union is confirmed and the patient returns to full weight-bearing without pain 7
Critical Pitfalls to Avoid
Failure to obtain weight-bearing radiographs can miss occult instability from associated deltoid or anterior tibiofibular ligament tears, leading to inappropriate conservative management of an unstable fracture 1, 4
Missing associated ligamentous injuries compromises outcomes—if medial tenderness or swelling is present, consider stress radiographs to evaluate for deltoid ligament disruption 1, 4
Overly aggressive rehabilitation before adequate healing can lead to displacement or nonunion 2, 8
Be aware that 5-33% of patients may have persistent pain and instability at 1 year, and 3-34% experience recurrent ankle sprains, necessitating close follow-up 2
When to Consider Surgical Intervention
If the fracture is truly nondisplaced and stable on weight-bearing films, surgery is not indicated 4
However, if subsequent loss of position occurs during conservative treatment or if anatomical reduction cannot be maintained, open reduction and internal fixation becomes necessary 4
Surgical intervention is required if weight-bearing radiographs reveal a medial clear space >4 mm, indicating instability despite initial appearance of minimal displacement 1, 3