Minimally displaced pediatric humerus lateral condyle fractures: risk factors for displacement and outcomes of delayed surgery.

The purpose of this study was to identify risk factors for management failure in pediatric minimally displaced lateral condyle fractures of the distal humerus (LCHFx) and compare outcomes between initial nonoperative and operative cohorts. A retrospective chart review of LCHFx was conducted to identify children treated with displacement <2 mm and initial nonoperative management. Classification and Regression Trees (CART) were constructed to identify predictors for failure of nonoperative management (further displacement requiring operative intervention). One hundred forty nonoperative children met initial inclusion. CART analysis identified the internal oblique measurement of pre-treatment fracture displacement of >1.2 mm to be the most predictive of nonoperative failure. Fractures with displacement of >1.2 mm had a 58.3% rate of failure compared to 1.3% for those <1.2 mm of initial displacement (P < 0.001). Thirty-seven percent of nonoperative children required revision treatment compared to only 12% of operative children (P = 0.034). LCHFx with minimal displacement (1-2 mm) have a relatively high risk for failure when initially managed without surgery and should either be monitored closely or considered for early operative management when appropriate.