Humero-ulnar external fixation of pediatric supracondylar humeral fractures using an adult wrist external fixator.

Abstract

Although cross-pinning is widely used to treat pediatric supracondylar humeral fractures, it involves risks of nerve injury, malunion, and compartment syndrome. In this two-center retrospective observational study, we compared the outcomes of humero-ulnar external fixation using an adult wrist fixator with those of conventional pinning for pediatric supracondylar humeral fractures. Given the technical complexity of Slongo lateral external fixation, we evaluated a simpler joint-spanning external fixation method. This study enrolled 37 children: 19 treated with pinning between 2010 and 2017, and 18 treated with external fixation from 2018 onwards at two hospitals. All patients were followed up for at least 12 months. Clinical outcomes were assessed using Flynn's criteria. The Baumann, tilting, and carrying angles were measured. Patient backgrounds were comparable between the two groups. External fixation required a significantly longer surgical time (mean 65.3 vs. 38.9 min for pinning); however, postoperative immobilization with a plaster cast was not required. Radiographic parameters were similar between the groups; however, the pinning group demonstrated greater discrepancies in Baumann and tilting angles than the unaffected side. Flynn outcomes were good or excellent in 53 % of pinning cases and 61 % of external fixation cases. Varus deformities were slightly less frequent in patients who underwent external fixation. Complications included pin-site infections (four pinning, one external fixation) and transient preoperative nerve palsy in both groups, which were resolved spontaneously. No new nerve injuries or compartment syndrome occurred. Humeral-ulnar EF provides safe and stable fixation with favorable outcomes and may therefore be a useful option for pediatric supracondylar humeral fractures, particularly in severely displaced cases.