Abstract
BACKGROUND: After displaced supracondylar humerus fractures (SCHF) in children, residual deformities are common with cubitus varus (CV) being the clinically most visible. Distal fragment malrotation may lead to instability, fragment tilt and subsequent CV. Detection and assessment of malrotation is difficult and the fate of post-traumatic humeral torsion deformity is unknown. The aim of this study was to evaluate the incidence of humeral torsion differences in children with surgically treated SCHF and to observe spontaneous changes over time. METHODS: A cohort of 27 children with displaced and surgically treated SCHF were followed prospectively from the diagnosis until twelve months after trauma. Clinical, photographic, sonographic and radiological data were obtained regularly. Differences in shoulder and elbow motion, elbow axis, sonographic humeral torsion measurement and radiological evaluation focusing on rotational spur were administered. RESULTS: Six weeks after trauma, 67% of SCHF children had a sonographically detected humeral torsion difference of > 5° (average 14.0 ± 7.6°). Of those, 44% showed a rotational spur, slight valgus or varus on radiographs. During follow-up, an average decrease of the difference from 14° (six weeks) to 7.8° (four months) to 6.5° (six months) and to 4.9° (twelve months) was observed. The most significant correction of posttraumatic humeral torsion occurred in children < 5 years and with internal malrotation > 20°. CONCLUSION: After displaced and surgically treated SCHF, most children had humeral torsion differences of both arms. This difference decreased within one year after trauma due to changes on the healthy side or correction in younger children with severe deformity. LEVEL OF EVIDENCE/CLINICAL RELEVANCE: Therapeutic Level IV.