Epidemiology of pelvic ring injuries.

3260 patients with pelvic and acetabular fractures were assessed using a standardized documentation form by collating the data on 1905 patients treated at the Department of Traumatology of the Hannover Medical School together with those patients treated between 1991 and 1993 in the German Multicentre Study Group (Pelvis) of the German Trauma Society and the German Section of the AO International. 2551 patients had pelvic ring injuries. 61.7% of the patients were multiply injured. 12.2% were suffering a complex pelvic trauma defined as a pelvic injury with concomitant soft tissue injury. The pelvic ring fracture was classified as stable in 54.8% (type A injury), as rotationally unstable in 24.7% (type B injury), and as unstable in translation in 20.5% (type C injury). There were concomitant acetabular fractures in 15.7%. The most frequent single lesions affecting the pelvic girdle were fractures of the ischiopubic bones (transpubic instability), injuries involving the sacroiliac joint (transiliosacral instability), and sacral fractures (transsacral instability). The overall rate of operative stabilizations was 21.6%. Type B injuries were stabilized in 28.9% and type C injuries in 46.7%. The overall mortality rate was 13.4%, depending significantly on the associated extrapelvic trauma. In complex pelvic injuries, the mortality rate was 31.1% whereas for pelvic fractures without concomitant soft tissue injury the rate was only 10.8%.