Are outcomes after fixation of distal humerus coronal shear fractures affected by surgical approach? A systematic review and meta-analysis

BACKGROUND: Surgical management of coronal shear fractures of the distal humerus is associated with a high rate of complications. Several surgical approaches have been described to address these fractures. The complication profiles associated with each approach have not previously been compared, and that is the aim of the present study. METHODS: A systematic review of the literature was performed to identify all studies addressing coronal shear fractures of the distal humerus published between 2001 and January 2022. Of the 189 articles identified, 45 met the criteria for inclusion. Summaries of continuous data were calculated using the inverse variance method for pooling with random effects models. Fixed effects model estimates were reported unless significant heterogeneity was observed between studies. A subset of 6 studies reported the surgical approach and complications associated with the operative management of capitellar shear fractures without posterior comminution. The complication profiles of the extended lateral and anterolateral approaches were compared. RESULTS: The 45 studies included yielded 899 patients. The average age was 44.9 years (95% confidence interval [CI]: 39.7 to 50.2). The fracture type was Dubberley A in 38% (n = 342), Dubberley B in 33% (n = 300), and not reported in the remainder. The reoperation rate was 13.8% (95% CI: 9.6% to 19.5%). Pooled complication rates included post-traumatic arthritis in 21.2% (95% CI: 18.0% to 24.9%), heterotopic ossification in 12.0% (95% CI: 9.2% to 15.6%), nerve injury in 7.8% (95% CI: 5.6% to 10.9%), and avascular necrosis in 7.4% (95% CI: 5.3% to 10.2%). The complication rate in noncomparative studies was 25.8% following the lateral approach and 16.7% following the anterolateral approach. Reported complications following the anterolateral approach were pain (9.5%) and nerve injury (7.1%). Reported complications following the lateral approach included arthritis (9.1%), heterotopic ossification (6.1%), avascular necrosis (4.5%), instability (3.0%), nerve injury (1.5%), and wound issues (1.5%). DISCUSSION AND CONCLUSION: Complications are common following operative management of capitellar shear fractures. In noncomparative studies, the complication rate was higher following the extended lateral compared to the anterolateral approach for Dubberley A fractures. Additionally, the reported complications following the extended lateral approach may impact long-term outcomes. Insufficient comparative evidence currently exists to recommend one approach over the other. High-quality comparative studies are needed.