Anatomic Study of Superior Cluneal Nerves: Application to Low Back Pain and Surgical Approaches to Lumbar Vertebrae.

OBJECTIVE: The aim of this study was to investigate the anatomy of the superior cluneal nerves more proximal to the posterior layer of the thoracolumbar fascia.

METHODS: Twelve sides of 6 fresh-frozen cadavers were used. The age at death ranged from 54 to 88 years. After a transverse skin incision 10 mm above the iliac crest, the superior cluneal nerves were detected by blunt dissection and traced back to the dorsal root ganglia. The diameter of the nerves from L1 to L3 was measured. Also, the relationship to the erector spinae muscle and dorsal ramus was recorded.

RESULTS: The mean diameters of the origin of the L1, L2, and L3 were 1.71 ± 0.29 mm, 1.73 ± 0.40 mm, and 1.52 ± 0.55 mm, respectively. On 7 sides (58.3%) for L1, seven sides (58.3%) for L2, and 10 sides (83.3%) for L3, the nerves pierced the iliocostalis muscle. One side (8.3%) for L2 and one (8.3%) for L3 had no cutaneous branch.

CONCLUSIONS: The results of this study could help to elucidate the anatomy of the superior cluneal nerves and help avoid complications during surgical approaches to the lumbar spine.