What is the recommended treatment for a patient with an undisplaced lateral malleolus fracture, considering potential underlying conditions such as osteoporosis?

Treatment of Undisplaced Lateral Malleolus Fracture

For undisplaced lateral malleolus fractures, immediate weight-bearing with mobilization is the preferred treatment approach, avoiding unnecessary immobilization that delays rehabilitation. 1, 2

Initial Management

Confirm Stability

• Verify fracture stability through weight-bearing radiographs if possible, as the most critical criterion in malleolar fracture treatment is stability 3
• A medial clear space of <4 mm confirms stability 3
• Look for red flags indicating instability: medial tenderness, bruising or swelling, fibular fracture above the syndesmosis, or high-energy mechanism 3

Treatment Protocol

• Implement immediate weight-bearing and mobilization rather than cast immobilization 2
• This approach results in earlier rehabilitation compared to 4 weeks of plaster immobilization, with no increase in complications 2
• If immobilization is chosen (for patient comfort or compliance concerns), limit to 6-8 weeks with protected weight-bearing 1

Pain Management Algorithm

Start with acetaminophen as first-line analgesia 1

• Avoid NSAIDs if cardiovascular or renal comorbidities exist 1
• Reserve short-term narcotic medications only for severe pain uncontrolled by acetaminophen 1

Rehabilitation

Initiate early mobilization immediately as tolerated 1

• Begin range-of-motion exercises for ankle and foot within the first few days 1
• Progress weight-bearing as pain and healing allow 1
• Early physical training and muscle strengthening prevent complications of immobility 1

Addressing Underlying Osteoporosis

For patients over 50 years with fragility fractures, osteoporosis treatment is mandatory to prevent subsequent fractures 3

Calcium and Vitamin D

• Prescribe calcium 1000-1200 mg/day plus vitamin D 800 IU/day 3, 1
• This combination reduces non-vertebral fractures by 15-20% and falls by 20% 3, 1

Pharmacological Treatment

• Oral bisphosphonates (alendronate or risedronate) are first-choice agents 3, 1
• These drugs reduce vertebral, non-vertebral, and hip fractures 3, 1
• For patients with oral intolerance, dementia, malabsorption, or non-compliance, use intravenous zoledronic acid or subcutaneous denosumab 3
• Prescribe for 3-5 years initially, longer if high risk persists 3

Follow-Up Protocol

Obtain follow-up radiographs at 6-8 weeks to confirm healing 1

• Monitor for medication tolerance and adherence, as long-term adherence is typically poor 3, 1
• If symptoms persist beyond 6-8 weeks despite negative initial radiographs, consider MRI as the most sensitive study for occult fractures with bone marrow edema patterns 3
• CT without IV contrast is useful for detecting radiographically occult fractures if MRI is unavailable 3

Critical Pitfalls to Avoid

Do not assume all undisplaced fractures are stable 3

• The lateral malleolus is the key to anatomical reduction in ankle fractures, and even subtle displacement can lead to late degenerative arthritis 4
• Incomplete reduction of the lateral malleolus results in residual talar tilt and poor long-term outcomes 4
• If any doubt exists about stability, obtain weight-bearing radiographs to assess the medial clear space 3

Do not overlook associated injuries 3

• 70% of ankle fractures result in some cartilage injury 3
• Ligamentous injuries occur in 15% of cases without radiographic fracture 3
• If pain persists beyond expected healing time, MRI is superior to repeat radiographs for detecting soft-tissue injuries 3