Imaging diagnosis of spiral tibiofibular fracture combined with occult fracture of posterior malleolus

Objective To evaluate the diagnostic value of CT and MRI for the spiral tibiofibular fracture combined with the occult fracture of posterior malleolus. Methods From July 2007 to December 2007, 39 patients were admitted to our hospital for the spiral tibiofibular fracture combined with the posterior malleolar fracture. Their radiographs, CT and MRI images were analyzed and compared. Results The imaging diagnosis revealed that 30 cases of spiral tibial and fibular shaft fractures, 7 cases of spiral tibial shaft fractures and 2 cases of spiral fibular shaft fracture had been complicated with the occult fracture of posterior malleolus. We found 30 long and 9 short oblique crack fractures, including 7 slightly dislocated fractures. The diagnostic accuracy for the posterior malleolar fracture was 10. 3%, 94. 9% and 100% in plain films, CT images and MRI images, respectively; the false negative rate for the posterior malleolar fracture was respectively 89. 7%, 5. 1% and 0. Conclusion CT and MRI can improve the diagnostic accuracy of the occult posterior malleolar fracture and MRI is the most sensitive examination. Key words: Fractures, clossed; Magnetic resonance imaging; Tomography scanners, X-ray computer