Treatment of Medial Malleolus Fractures with Walking Boot
Non-displaced stable medial malleolus fractures can be treated with a walking boot, while displaced unstable fractures require open reduction and internal fixation (ORIF). 1
Assessment of Fracture Stability
- Weight-bearing radiographs provide crucial information about fracture stability, which is the most important criterion in determining treatment approach 2
- A medial clear space of <4 mm confirms stability of the fracture 2
- Standard radiographic protocol should include anteroposterior, lateral, and mortise views to properly assess the fracture 2, 3
- MRI without IV contrast is valuable for assessing associated bone marrow contusions and soft-tissue abnormalities when radiographs are inconclusive 3
Treatment Algorithm Based on Fracture Characteristics
Non-Displaced Stable Fractures (≤2 mm displacement)
- Conservative treatment with a walking boot is safe and effective 1
- Similar functional outcomes have been demonstrated between surgical and conservative treatment for fractures displaced 1-2 mm 1
- Conservative treatment has shown good functional outcomes even with mean displacement of 3.8 mm in some studies 1
Displaced Unstable Fractures (>2 mm displacement)
- Open reduction and internal fixation (ORIF) is the standard treatment as recommended by the AO Group 4
- Indicators of instability requiring surgical intervention include:
- Medial tenderness, bruising, or swelling
- Fibular fracture above the syndesmosis
- Bi- or trimalleolar fractures
- Open fracture
- High-energy fracture injury 2
Special Considerations
Stress Fractures of the Medial Malleolus
- Athletes with radiographic signs of a medial malleolar stress fracture who desire early return to activity should be treated by ORIF 5
- Athletes with normal radiographs but positive bone scans can be treated non-surgically with immobilization 5
- Return to full activity typically occurs between 6-8 weeks after treatment initiation 5
Vertical Shear Fractures
- These less common fracture patterns often require specialized fixation techniques such as lag screws, buttress plating, or neutralization plates 6
- Mini-screws fixation has shown good outcomes for small fragment medial malleolus fractures 7
Monitoring and Follow-up
- Regular radiographic follow-up is essential to ensure proper healing and alignment
- MRI may be used to confirm complete healing in cases where radiographs are inconclusive 8
- Non-union rates are slightly higher with conservative treatment (3.5%) compared to surgical treatment (1.7%), but still relatively low overall 1
Pitfalls and Caveats
- Fractures may be overlooked on routine radiographs; special attention to areas of tenderness is recommended 3
- Untreated fractures can lead to functional limitations and post-traumatic arthritis 3, 4
- Patients with osteoporosis may require extended immobilization 8
- The literature regarding isolated medial malleolar fractures is scarce and of low quality, with limited high-quality comparative studies between surgical and conservative treatment 1