Which pediatric supracondylar humerus fractures are high risk for conversion to open reduction?

Supracondylar humerus fractures are common pediatric injuries encountered by orthopedic surgeons. Displaced fractures are treated operatively with closed reduction and percutaneous pinning or open reduction of injuries that cannot be adequately closed reduced. The purpose of this study is to identify preoperative injury characteristics associated with open reduction. Retrospective chart review was performed on all AO type 13A (Gartland type) supracondylar humerus fractures in patients 2-13 years old treated surgically at a single level 1 trauma center over 6 years. Preoperative demographics and radiographic parameters were obtained for all patients. Primary outcomes were closed reduction or conversion to open reduction of fractures prior to k-wire fixation. Initial bivariate analysis was done using Chi-square tests. Final multivariate analysis with Bonferonni correction was performed using a backward, stepwise regression model including potential predictor variables identified in the bivariate analysis. A total of 211 patients received surgical treatment and 18 of those patients (8.5%) failed closed reduction and underwent open reduction. Final multivariate analysis demonstrated that only flexion type [relative risk (RR), 10.2] and coronal displacement more than 7 mm (RR, 4.49) were significant preoperative factors for conversion to open reduction. Patients with significant coronal displacement and flexion-type injuries are markers of challenging reduction and are at high risk for conversion to open reduction.