Treatment of Non-Displaced Posterior Malleolus Ankle Fracture in a 26-Year-Old Female
Conservative management with immobilization in a posterior splint or walking boot is the recommended treatment for a non-displaced posterior malleolus fracture in this young patient, with close radiographic follow-up to confirm maintenance of alignment. 1
Initial Assessment and Imaging
- Obtain standard three-view ankle radiographs (anteroposterior, lateral, and mortise views) to confirm the fracture is truly non-displaced and assess overall ankle alignment 1
- Weight-bearing radiographs are critical to determine stability—a medial clear space <4 mm confirms fracture stability and supports conservative management 2
- CT imaging is often needed for proper evaluation of posterior malleolus fractures, as these can be complex and may be associated with syndesmotic injuries 1, 3
- Assess for signs of instability including medial tenderness, bruising, swelling, or associated ligamentous injury which would indicate different management 2
Conservative Treatment Protocol
- Apply a posterior splint to immobilize the ankle joint in a neutral position, ensuring the splint extends from below the knee to beyond the toes 1
- Posterior splints provide better pain relief within the first 2 weeks of injury compared to other immobilization methods 1
- Transition to a functional walking boot or lace-up ankle brace after initial immobilization period for early mobilization 2
- Avoid weight-bearing on the affected extremity until proper evaluation confirms stability 1
Follow-Up and Monitoring
- Obtain serial radiographs to confirm maintenance of alignment and assess healing progression 2, 1
- Weight-bearing radiographs during follow-up to reassess stability (medial clear space <4 mm confirms continued stability) 2
- Monitor for delayed union or nonunion, though this is rare in non-displaced fractures treated conservatively 2
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 2
- Missing associated ligamentous injuries compromises outcomes—if medial tenderness or swelling is present, consider stress radiographs to evaluate for deltoid ligament disruption 2
- Overly aggressive rehabilitation before adequate healing can lead to displacement or nonunion 2
- Monitor for signs of compartment syndrome or vascular compromise after splinting, indicated by blue, purple, or pale extremity color 1
Indications for Surgical Intervention
- Surgical treatment is required if weight-bearing radiographs reveal a medial clear space >4 mm, indicating instability despite initial appearance of minimal displacement 2
- Large posterior malleolus fragments (>15 mm) that may affect joint stability may require surgical intervention 4
- Displaced posterior malleolus fractures with tibial plafond depression or syndesmotic instability require operative fixation 5, 3
Rationale for Conservative Management in This Case
Conservative treatment is recommended for non-displaced posterior malleolus fractures (Bartoníček type I, II, and undisplaced type III) without tibial plafond depression or syndesmotic injury 5. Clinical outcomes in conservatively treated non-displaced posterior malleolus fractures are favorable when ankle stability is maintained 5. The dorsal syndesmotic and medial deltoid ligaments control ankle joint stability, and when these are intact with a non-displaced fracture, conservative management is appropriate 6.