Fully displaced pediatric supracondylar humerus fractures: Which ones need to go at night?

Background: Challenges remain in determining which displaced supracondylar humerus fractures are safe to postpone surgical treatment until daylight hours. The purpose of this study is to determine which characteristics can be identified to guide the timing of treatment of supracondylar humerus fractures. Methods: 225 completely displaced Gartland extension type 3/4 supracondylar humerus fractures in healthy patients that presented between 6 am and 7 am were identified. Data were collected retrospectively. Data analysis included univariate, multivariable logistic regression and classification and regression tree analysis. Results: 5% (78/225) underwent surgical treatment the night they presented, while 65% (147/225) were treated the next day. Overall complication rate was 6%, with no difference based on timing of surgery. 12% (28/225) presented with a motor nerve injury, while 6% (14/225) a "pink pulseless" extremity. Statistical analysis found the most reliable radiographic predictor to be the maximum displacement on the anterior-posterior or lateral view. Classification and regression tree analysis developed a clinical algorithm; patients with a "pink pulseless" extremity or motor nerve injury were recommended for surgery overnight, while those with an anterior-posterior or lateral view < 25 mm were recommended for surgery the next day. Conclusion: This study provides guidance on the timing of treatment for displaced supracondylar humerus fractures that present overnight. We provide a simple algorithm with three key clinical predictors for timing of treatment: presence of a "pink pulseless" arm, presence of a motor nerve injury, and displacement of any cortex by at least 25 mm (anterior-posterior or lateral view). This provides a step forward to help practitioners make safer evidenced-based timing decisions for their patients. Level of evidence: Prognostic Study, Level II.