Comparative Outcomes of Pinning Versus Permanent Fixation for Adolescent Supracondylar Humerus Fractures

INTRODUCTION: Supracondylar humerus (SCH) fractures are a common injury treated with closed reduction and percutaneous pinning in children compared to open reduction and internal fixation with plates and screws in adults. However, the optimal treatment strategy for adolescent patients remains unclear. The purpose of this study is to compare the surgical outcomes of SCH fractures treated with pinning versus permanent fixation in adolescents. METHODS: A retrospective chart review was performed on all children aged 10 to 17 years old with an extra-articular SCH fracture who underwent surgical fixation between 2012 and 2022 at a level one pediatric trauma center. A total of 118 patients met inclusion criteria, with pin fixation in 105 patients and permanent fixation in 13 patients. Bivariate analysis using the Fisher exact test and a t test for continuous variables was performed. A multivariate regression model evaluated the effect of fixation type on time to union after adjusting for surgical approach, Gartland classification, and age. RESULTS: The mean age was 10.9 years for the pins-only group and 12.8 years for the permanent fixation group (P<0.001). Unadjusted analysis of time to union was similar between groups (mean difference of 10.1 d, 95% CI: -22 to 2 d, P=0.09), as well as the presence and resolution of preoperative and postoperative nerve deficits. The average elbow arc of motion was significantly higher in the permanent fixation group (135 vs. 123 degrees, P=0.01). The multivariate model demonstrated that every additional year of age increased time to union by 3.5 days (P<0.05). Fixation type and surgical approach significantly impacted time to union: pin fixation via an open approach increased time to union by 14.2 days compared to pin fixation performed via a closed approach (P<0.05). Screw fixation via a closed approach decreased time to union by 10.4 days (P<0.05). Additionally, Gartland type IIB and type III fractures were associated with longer union times compared to type IIA fractures (P<0.05). CONCLUSIONS: Adolescent patients with SCH fractures had a longer time to union associated with the independent factors of increasing age above 10 years old, more severe fracture type (IIB or III), and those that underwent fixation via an open approach. Permanent fixation demonstrated significantly greater average flexion-extension arc of motion compared to pins-only, though this difference is unlikely to be clinically significant and could be attributed to the small sample size in the permanent fixation group. There were similar rates of nerve deficits and heterotopic ossification outcomes in the permanent fixation group compared to the pins-only fixation group. LEVELS OF EVIDENCE: Level III-therapeutic study.