[Functional limitation of the forearm after shaft fracture in childhood. Possible role of the antebrachial interosseous membrane: MRI and ultrasound studies].

Based on follow-up examinations of 16 patients aged 5 to 15 years, the integrity of the interosseous membrane following forearm shaft fracture was evaluated. The examinations which included magnetic resonance imaging (MRI) and ultrasound scanning of both the fractured and the nonfractured forearms were conducted 4 to 81 months after fracture. Using a 1.5 T MR tomograph, we obtained 20 cross-sectional images arranged over the entire length of the forearm which was in neutral position, while sonographicly at 7.5 MHz we obtained cross-sectional views of the proximal, middle and distal forearm thirds with the forearm in pronation, neutral position and supination at a time. The MR image of the interosseous membrane is a thin hypointense line, occasionally showing low contrast irregularities on the fractured side such as thickenings, tears or curvature inconstancies which would suggest membrane alterations. However, these alterations appear to be less than expected. They are not clearly seen in the ultrasound views, where the interosseous membrane is found as an echorich line. According to our preliminary results, there seems to be a correlation between MR-detected interosseous membrane alterations and initial fracture dislocation as well as functional fracture outcome, particularly forearm rotation.