Introduction: Although both-bone forearm fractures in children may result in severe limitation of forearm rotation, finding the cause remains a diagnostic challenge. This study tries to evaluate the role of rotational malunion, bony impingement and contractures of the interosseous membrane.
Patients and methods: Children (5-16 years) who suffered from a both-bone forearm fracture in diaphysis or distal metaphysis with a limitation of pronation/supination ≥40° at ≥6 months after trauma were included for analysis with conventional radiographs, computed tomography (CT) and magnetic resonance imaging (MRI).
Results: A total of 410 children with a both-bone forearm fracture were prospectively followed in four Dutch hospitals. At a median of 205 days, 7.3 % suffered from a limitation of pronation/supination ≥40°. 14 children were included (median limitation of 40°) and the radiographs revealed a median maximum angular malunion of 16°. CT analysis showed rotational malunion of both radius (median 19°) and ulna (median 9°). MRI analysis revealed neither bony impingement nor contractures of the interosseous membrane.
Conclusions: Three-dimensional imaging of children with a severe limitation of pronation/supination after a both-bone forearm fracture revealed rotational malunions of both radius and ulna without bony impingement or soft tissue contractures.
Level of evidence: Prospective multicenter study, Level 2.