Neurological and vascular injury associated with supracondylar humerus fractures and ipsilateral forearm fractures in children

BACKGROUND:: Approximately 5% of supracondylar humerus fractures in children are associated with an ipsilateral forearm fracture, often referred to as a floating elbow when both injuries are displaced. Historically, these patients have higher complication rates than patients with an isolated supracondylar humerus fracture. The purpose of this study was to review the acute neurologic and vascular injuries in patients with ipsilateral, operative supracondylar humerus and forearm fractures and compare the findings with a cohort of isolated, operative supracondylar humerus fractures. METHODS:: We performed an IRB-approved, retrospective review of all pediatric patients with ipsilateral, operative supracondylar humerus and forearm fractures from a single institution and compared our findings to a cohort of isolated, operative supracondylar humerus fractures. RESULTS:: A total of 150 patients with operative supracondylar humerus and ipsilateral forearm fractures were compared with 1228 patients with isolated, operative supracondylar humerus fractures. Twenty-two of the 150 (14.7%) floating elbow patients had documented pretreatment nerve palsies compared with 96/1228 (7.8%) of isolated injury patients (P=0.006). Eighteen of 22 nerve palsies were in patients with forearm fractures that required reduction. The overall incidence of nerve palsy was 18.9% (18/95) when a forearm fracture required reduction compared with only 7.3% (4/55) in a forearm fracture that was not reduced (P=0.05). We did not find a significant difference in the rate of pulseless extremities when comparing the ipsilateral (6/150 4%) and isolated (50/1228 4.1%) injury patients. No compartment syndromes were identified in any patient with an ipsilateral injury. CONCLUSIONS:: The rate of acute neurologic injury in ipsilateral supracondylar humerus and forearm fractures is almost twice than that found in patients with isolated supracondylar humerus fractures. This rate increases further when the forearm fracture requires a manipulative reduction. The likelihood of a pulseless extremity was not dependent upon the presence of a forearm injury in our study. The presence of an ipsilateral forearm fracture should alert the surgeon to carefully assess the preoperative neurovascular status of patients with supracondylar humerus injuries. LEVEL OF EVIDENCE:: Level III.