Applied anatomy of vessels,nerves and adjacent structures of the lower lumbar vertebrae

Objective:To provide anatomic data for lower lumbar spine interbody fusion through the extreme lateral approach (XLIF). Methods:This study investigated 30 human cadavers to record the course, distribution and relationship of vessels and nerves and their adjacent structures of lower lumbar vertebrae. Results:The course and location of the 1st, 2nd and the 3rd lumbar arteries and veins were more constant, which followed the center of the corresponding lumbar vertebrae. However, the 4th lumbar artery and vein varied greatly. Vessels of 11 (36.7%)of all samples coursed on the surface of L4/5 interspace. The diameters of L 3~5 spinal nerves around intervertebral foramen and the distance from the anterior branches of those nerves to the corresponding lower disc gradually increased. The angles between the anterior branches of the L 3~4 spinal nerves and the median sagittal planes of corresponding vertebral body increased, but decreased again at the L5 level. The operation windows of L 3~5 gradually increased and the left ones were wider than the right. Conclusions:The XLIF of L 3 /L 4 , L 4 /L 5 disc is safe, reliable and practical. However the L 5 /S 1 disc interbody fusion is impossible for the block of bilateral iliac crests.