Supracondylar humeral fractures in children: beware the medial spike.

Supracondylar humeral fractures are common in children, but there are no classification systems or radiological parameters that predict the likelihood of having to perform an open reduction. In a retrospective case-control study we evaluated the use of the medial spike angle and fracture tip-skin distance to predict the mode of reduction (closed or open) and the operating time in fractures with posterolateral displacement. A total of 21 patients (4.35%) with a small medial spike angle (< 45°) were identified from a total of 494 patients, and 42 patients with a medial spike angle of > 45° were randomly selected as controls. The medial spike group had significantly smaller fracture tip-skin distances (p < 0.001), longer operating times (p = 0.004) and more complications (p = 0.033) than the control group. There was no significant difference in the mode of reduction and a composite outcome measure. After adjustments for age and gender, only fracture tip-skin distance remained significantly associated with the operating time (β = -0.724, p = 0.042) and composite outcome (OR 0.863 (95% confidence interval 0.746 to 0.998); p = 0.048). Paediatric orthopaedic surgeons should have a lower threshold for open reduction when treating patients with a small medial spike angle and a small fracture tip-skin distance.