In pelvic bone fracture the incidence of concomitant nerve injury is not known exactly. The factors promoting nerve injury in connection with closed skeletal trauma are; 1) proximity of the nerve to unyielding anatomical structures, 2) morphological characteristics of the neural elements and supporting structures and 3) inherent tolerance to trauma, What is the relation between lumbo-sacral nerve injury and the fracture pattern of the pelvis?

We studied 97 pelvic bone fracture patients under the physical findings, radiological findings and electrophysiologic findings.

The results of these studies were as follows;

1. In 97 pelvic bone fracture patients the incidence of concomitant nerve injury was 11 cases (11.3%)

2. In 11 lumbosacral nerve injury patients we seen stable fracture in 2 cases, unstable fracture in 9 cases, therefore nerve injuries were more correlate with unstable fracture than stable fracture.

3. In 9 lumbosacral nerve injury patients unstable pelvic bone, fracture, We seen only anterior pelvic ring instability in 0 case only posterior pelvic ring instability in 6 cases, both instability in 3 cases, therefore nerve injuries were more correlate with posterior pelvic ring instability than anterior pelvic ring instability.

4. In 11 lumbosacral nerve injury the sites of these injuries were lumbosacral trunk in 9 cases, obturator nerve in 7 cases, superior gluteal nerve in 5 cases, femoral nerve in 4 cases, sciatic nerve in 2 cases, therefore combined nerve injuries were common than single one