Treatment of Bimalleolar Fracture of the Lower Extremity
Surgical fixation with open reduction and internal fixation (ORIF) is the recommended treatment for most bimalleolar ankle fractures to restore anatomical alignment and joint stability, allowing for early mobilization and better functional outcomes. 1
Initial Assessment and Management
- Evaluate the fracture pattern, displacement, and stability through appropriate imaging (typically three-view radiographs) to guide treatment decisions 2
- Assess soft tissue status and viability upon admission, as this will determine timing and approach to surgery 3
- Consider patient factors including age, functional status, comorbidities, and bone quality when selecting treatment approach 1, 3
Surgical Management
Indications for Surgery
- Displaced bimalleolar fractures with joint incongruity 1
- Unstable ankle fractures with widening of the medial clear space 4
- Fractures with postreduction radial shortening >3 mm, dorsal tilt >10°, or intra-articular displacement 1
Surgical Techniques
Open reduction and internal fixation (ORIF) is the standard treatment for most bimalleolar fractures 5, 3:
Syndesmotic fixation may be required if the syndesmosis is disrupted:
- Transsyndesmotic screws are commonly used but require a second surgery for removal 7
- Consider deltoid ligament repair as an alternative to syndesmotic fixation in bimalleolar equivalent fractures (lateral malleolus fracture with deltoid ligament injury), as it shows comparable outcomes while avoiding the need for implant removal 7
Special Considerations for Elderly Patients
- In elderly patients with osteoporosis, consider using locking plates which provide better fixation in fragile bone 3
- For very frail patients or those with poor skin condition, consider less invasive options:
Non-Surgical Management
- Conservative treatment with cast immobilization may be appropriate for stable, non-displaced fractures 1
- However, in displaced fractures, conservative treatment has limited indications and must be carefully selected due to risks of secondary displacement and skin complications 3
Perioperative Care
- Antibiotic prophylaxis is recommended for open reduction and internal fixation of ankle fractures 1
- Short-course, single-agent regimens using cephalosporins are typically sufficient 1
- For patients with high risk of surgical site infection (BMI, ASA ≥ 3, diabetes, open fracture), extended antibiotic prophylaxis may be considered 1
Postoperative Management
- Appropriate pain management and early mobilization are essential 1
- Implement a rehabilitation program with early physical training and muscle strengthening 1
- Weight-bearing restrictions typically last 6-8 weeks, but protocols may vary based on fracture pattern, fixation stability, and bone quality 3, 6
- Monitor for complications including infection, malunion, and post-traumatic arthritis 5
Long-Term Outcomes and Prognosis
- Long-term studies (10-14 years) show that approximately 52% of patients with surgically treated bimalleolar fractures have good to excellent outcomes, while 24% have poor outcomes 5
- Bimalleolar fractures tend to have worse functional outcomes compared to lateral malleolar fractures with medial ligamentous injury 4
- Post-traumatic arthritis may develop over time, with increasing incidence in longer-term follow-up 5
Common Pitfalls and Caveats
- Delayed treatment can lead to soft tissue complications and poorer outcomes 3
- Inadequate reduction of the ankle mortise may result in post-traumatic arthritis 5
- Overtightening of syndesmotic screws can lead to restricted ankle motion and need for early removal 7
- In elderly patients, poor bone quality may lead to fixation failure if appropriate implants are not used 3
- Patients with diabetes and other comorbidities have higher risk of surgical site infections and complications 1, 3