CT of the acetabular fracture

Nine patients with 10 injured hips, in whom acetabular fractures with posterior dislocation of the femoral heads were demonstrated on initial radiography, underwent CT. CT was found superior in detecting the presence of intra-articular bony fragments in Group A patients (40%), where conventional radiography exhibited congruous manipulative reduction of the joint surfaces. The spatial position of the intra-articular fragments could not be ascertained on conventional radiography in 40% of the patients in Group B, in whom congruous manipulative reduction could not be achieved and subluxation of the femoral heads was observed. On conventional radiography, it was also difficult to appreciate the presence of intra-articular fragments in 60% of the patients in Group B, in whom either the dislocation could not be reduced (40%) or the femoral head redislocated after close manipulative reduction (20%). CT proved its superiority in detecting the extent of the fractures of the acetabular roof, posterior and anterior acetabular margins, the quadrilateral plate along with rotation of the acetabular columns and displacements of the major fractured fragments. Associated fractures of the sacrum (20%), and traumatic lesions of the sacro-iliac joint (20%), not apparent on conventional radiography were well demonstrated by CT. As a result of CT, the treatment was changed in 60% of the patients in Group A, and 40% in Group B. In addition, CT permitted a better choice of surgical technique in the management of acetabular fractures. (author). 9 refs., 3 figs., 2 tabs