Sagittal Plane Residual Deformity in Pediatric Type II Supracondylar Humerus Fractures

Introduction: The incidence of residual deformity in the sagittal plane of the humerus (RDSPH) after nonoperative management of type II supracondylar humerus fractures (SCHFs), and the effects of such deformity on the overall arc of motion (AOM) of the elbow, are unknown. Our purpose was to analyze data collected prospectively on a large cohort of type II SCHF's to establish the incidence and extent of RDSPH, and the effects of the deformity on the elbow function, to further support our previously published recommendations on the treatment of type II SCHF. Methods: The clinical data and radiographs of 1107 pediatric type II SCHFs enrolled in a prospective registry, and followed for a minimum of 8 weeks, were retrospectively reviewed. The radiographs obtained during the latest follow-up appointment were examined for the presence of RDSPH, as demonstrated by the anterior humeral line falling anterior or posterior relative to the center of the capitellum. The amount of RDSPH in the sagittal plane was then calculated. We compared the treatment outcome of elbows with and without RDSPH by assessing the patients' AOM, the arc of flexion (AOF), and relative arcs of motion (R-AOM) and relative arcs of flexion (R-AOF) (as compared with the unaffected, contralateral elbow). Results: Overall, 799 (72.2%) fractures were treated nonsurgically, and 308 (27.8%) fractures were treated surgically. The overall incidence of RDSPH was 10.2%. None of the fractures managed operatively demonstrated residual deformity. The RDSPH was classified as mild in 35 fractures (3.2%), moderate in 64 fractures (5.7%) and severe in 14 fractures (1.3%). Therefore, the incidence of RDSPH in fractures treated nonoperatively was 14.1%. In fractures treated nonoperatively, the difference in AOM between those without (n=686) and with (n=113) RDSPH was <4 degrees (149.1 vs. 145.8 degrees,P=0.02). Those with and without RDSPH had a clinically similar AOF, with a mean difference of<4 degrees (134.5 vs. 137.9 degrees,P<0.0001). The differences in R-AOM and R-AOF between those with and without RDSPH were minimal (97.3% vs. 95.6% and 96.6% vs. 95.3%, respectively). A satisfactory outcome, defined as an R-AOM of at least 85% when compared with the unaffected, contralateral side at the latest follow-up, was achieved in 91% of fractures with RDSPH, and 93% of fractures without RDSPH. Discussion and Conclusion: The incidence of RDSPH in type II SCHF treated nonoperatively was 14%. In our cohort, nearly 99% of all RDSPH were mild to moderate. On the basis of the data presented in the current study, nonsurgical treatment of type II SCHF can provide a satisfactory recovery of AOM, AOF, R-AOM, and R-AOF, and a high rate of satisfactory outcomes, even in the presence of RDSPH.