Treatment of Subacute Displaced Comminuted Intraarticular Calcaneus Fracture with Posterior Subtalar Joint Involvement
For a subacute displaced comminuted intraarticular calcaneus fracture with a 14x13mm gap involving the posterior subtalar joint, surgical intervention with open reduction and internal fixation (ORIF) is strongly recommended to restore calcaneal anatomy and prevent long-term disability, as initial operative treatment leads to significantly better functional outcomes compared to nonoperative management. 1, 2
Diagnostic Confirmation
Before proceeding with treatment, obtain CT imaging without IV contrast to fully characterize the fracture pattern, as initial radiographs have only 87% sensitivity for calcaneal fractures and frequently miss the extent of comminution and articular involvement. 3, 4 CT is essential for identifying occult osteochondral fractures of the subtalar joint, particularly those involving the posterior facet. 3
Surgical Treatment Algorithm
Primary Surgical Approach
Proceed with open reduction and internal fixation using an extended lateral approach or minimally invasive technique, depending on soft tissue condition and surgeon expertise. 5
The extended lateral approach provides excellent visualization of the lateral wall, subtalar joint, and calcaneocuboid joint, allowing anatomical reduction of the posterior facet and restoration of calcaneal height, width, and alignment. 5
For patients with significant soft tissue compromise or in the subacute phase (3 weeks to 6 months post-injury), consider minimally invasive techniques through a small lateral approach to reduce wound complications while achieving adequate reduction. 6
The surgical goals are: (1) anatomical reduction of the posterior subtalar joint articular surface, (2) restoration of calcaneal height (Böhler's angle), (3) correction of calcaneal width, and (4) stable internal fixation without joint transfixation. 5
Evidence Supporting Operative Management
Patients who undergo initial ORIF followed by subsequent subtalar fusion (if needed) have significantly higher functional scores compared to those managed nonoperatively initially. 1, 2 Specifically:
- Maryland Foot Scores: 90.8 vs 79.1 (p < 0.0001) 1
- AOFAS ankle-hindfoot scores: 87.1 vs 73.8 (p < 0.0001) 1
- Fewer postoperative wound complications with initial ORIF 1
Initial operative treatment restores calcaneal shape, alignment, and height, which facilitates any future fusion procedure and creates better long-term functional outcomes. 1, 2
Timing Considerations
Given the subacute nature (defined as 3 weeks to <6 months post-injury), surgery should be performed as soon as soft tissue conditions permit. 3 The subacute timeframe still allows for anatomical reduction, though it may be more technically challenging than acute intervention. 3
Surgical Technique Specifics
Achieve anatomical reduction of the posterior facet of the subtalar joint under direct visualization or fluoroscopic guidance. 5
Use stable internal fixation with plates and screws to maintain reduction without transfixing the subtalar joint. 5
Intraoperatively verify: (1) congruity of the subtalar joint articular surface, (2) restoration of overall calcaneal shape, (3) adequate Böhler's angle restoration. 5
Bone grafting or bone substitutes are generally not necessary for most displaced intraarticular calcaneal fractures. 5
Alternative: Primary Subtalar Fusion
For severely comminuted Sanders IV fractures with extensive articular destruction where anatomical reconstruction is not feasible, consider primary subtalar fusion with percutaneous ORIF to maintain alignment. 7 This approach:
- Preserves soft tissue through minimally invasive techniques 7
- Restores calcaneal alignment without attempting impossible articular reconstruction 7
- May reduce wound complications compared to extensive open approaches 7
Common Pitfalls to Avoid
Do not rely solely on radiographs - CT is mandatory to assess the true extent of comminution and articular involvement, as radiographs miss significant fracture details. 3, 4
Avoid nonoperative management for displaced intraarticular fractures with significant gaps - this leads to symptomatic malunion requiring corrective subtalar distraction arthrodesis with inferior functional outcomes. 1, 2
Meticulous soft tissue handling is critical - wound complications remain a concern even with careful technique, but are more frequent after delayed corrective procedures for malunion. 1, 5
Do not overlook associated injuries - assess for compartment syndrome, open fracture components, and associated foot/ankle injuries. 5
Postoperative Management
Maintain non-weight-bearing status until radiographic evidence of healing (typically 8-12 weeks). 4, 6
Initiate physical therapy once appropriate to restore range of motion and strength. 4
Monitor for complications including wound healing problems, infection, malunion, and posttraumatic subtalar arthritis. 1, 5
Prognostic Factors
Factors adversely affecting outcomes include: severity of initial injury, open fractures, bilateral fractures, high body mass index, and smoking. 5 However, anatomical reduction of calcaneal shape and subtalar joint congruity are surgeon-controlled factors that significantly improve prognosis. 5