Anatomy of the anterior sacroiliac joint with reference to lumbosacral nerves

There are no detailed descriptions of the neural structures that may be see n during surgical interventions of the pelvis. Anatomic dissections were pe rformed to see which nerves are endangered in approaches to the anterior sa croiliac joint for plate fixations. Sixty cadavers were dissected bilateral ly. Fifty-one mere male and nine were female. L4 and L5 nerve roots were fo llowed along the sacroiliac joint from the intervertebral foramen to the en trance into the lesser pelvis. Measurements mere made between the nerves an d sacroiliac joint from the proximal end of the joint to the pelvic brim. T he L4 nerve root and the lumbosacral trunk (and not the L5 nerve root) were the nerves most susceptible to injury because of their course and proximit y to the sacroiliac joint. As a result, during the anterior approach and fi xation of the sacroiliac joint with plates, extreme care should be taken to identify the L4 nerve root or lumbosacral trunk or both at the anteroinfer ior third of the joint because the distance between the nerve and the joint is less than 1 cm.