[Diagnostic value of conventional roentgen image, computerized and magnetic resonance tomography in acute sprains of the foot. A prospective clinical study].

In order to gain satisfying results in the treatment of acute hyperflexion trauma to the foot, it is absolutely necessary to achieve an exact primary diagnosis because injuries to the tarsometatarsal joint are frequently missed primarily. Aim of this prospective clinical study was to evaluate the diagnostic reliability of conventional radiography, CT and MRI compared to each other. 75 consecutive patients after hyperflexion trauma to the foot were included. There were 47 males and 28 females with a mean age of 38 years. After admittance, pa-, lateral and 45 degrees oblique radiographs were taken as well as stress views in comparison to the contralateral foot. Furthermore, CT and MRI were performed in any patient. By conventional radiography, 48 metatarsal and 24 tarsal fractures were diagnosed as well as 17 cases of malalignment of the Lisfranc joint. Stress radiographies were not able to provide a more accurate diagnosis. By CT scans, however, 86 metatarsal and 74 tarsal fractures were detected. Moreover, we found malalignment in 31 and bony avulsions of Lisfranc's ligament in 4 patients. By MRI, finally, 85 metatarsal, 100 tarsal fractures and 31 cases of malalignment were diagnosed. Additionally, partial or complete tears of Lisfranc's ligament were depicted in 22 patients. The present study could clearly show the superiority of CT and MRI to conventional radiography in diagnosis of bony and ligamentous disorders of the Lisfranc joint. Therefore, extended diagnosis has to be demanded in all cases of hyperflexion trauma to the foot.