A sample of Chinese literature - MRI diagnosis of interosseous membrane injury in Maisonneuve fractures of the fibula

Objective: In Maisonneuve fractures of the fibula (MFF) it remains controve rsial whether there is an injury of the interosseous membrane (IOM) and how severely it ruptures. The author studied injuries to the IOM in MFF by MRI to elucidate this question. Method: Twelve patients were examined with MRI before operation. MRI examin ation to the leg was performed with knee coil in 2 steps to obtain a comple te image of the IOM. Using axial scan, we took T1 (TR500/TE40 msec), T1STIR and T2 sequence. The asymptote side was also examined in three patients as a comparison. Result: IOM was ruptured in a range of 32-112 mm, on average 79 mm proximal to the talar dome in all 12 patients. No IOM rupture was found at the leve l of high fibular fractures. IOM usually orients at the site 30 mm proximal to the talar dome. Anatomy and rupture of IOM are clearly visualized with T1 (TR500/TE40 msec) STIR sequence; haemorrhage and oedema would be seen be tter on a T2 image. Conclusion: The injury level of IOM in MFF is only at the distal 1/3 part o f the leg; it is not consistent with high fibular fractures. MFF is a speci al type of pronation-external rotation type, there are four stages in the c lassification of MFF: 1) injury of medial structures, including medial malleolar fracture or rupt ure of the deltoid ligament 2) rupture of the anterior tibiofibular ligament or avulsion fracture of on e of its bone insertions, or one associated with interosseous ligament rupt ure and partial rupture of IOM in the distal 1/3 of the leg 3) fracture of the proximal part of the fibula 4) avulsion fracture of the posterior tibial tubercle.