LOCATION OF THE EXTRAFORAMINAL LUMBAR NERVE ROOTS - AN ANATOMIC STUDY

Twelve cadavers were used to determine the anatomic location of the ex traforaminal lumbar nerve root in the intertransverse space, After exp osure of the transverse processes of the lumbar spine and the extrafor aminal lumbar nerve roots, direct measurements, including the nerve ro ot angle, nerve root diameter, distance to the superior facet, and the intertransverse space, were made bilaterally, The results showed that the extraforaminal nerve root angle and diameter and the distance bet ween the superior facet and lateral limit of the nerve root consistent ly increased from cephalad to caudal, The largest dimension for height and width of the intertransverse space was found at the level of L3-4 , and the smallest was found at the level of L5-S1. This information m ay be helpful in minimizing the incidence of injury to the lumbar nerv e root during a posterolateral approach to lumbar disc.