title: Anatomical study of preganglionic spinal nerve and disc relation at different lumbar levels: Special aspect for microscopic spine surgery.
abstract: BACKGROUND
  Lumbar microdiscectomy is a widespread popular method of treatment. One major challenge is the spine level dependent different anatomy and the limited sight on the nerve root during the surgical procedure.
  
  
  OBJECTIVE
  The aim was to analyze the specific anatomic relation of nerve root, intervertebral disc and intervertebral ganglion under determination of the specific nerve distances. Furthermore the relation between the disc and the corresponding nerve root was evaluated.
  
  
  METHODS
  Regular human lumbar spine specimens of body donors were included in the study. Microscopic assisted dissection was performed. The topographical distances between a defined disc measurement point (DP) and the corresponding nerve root shoulder (NS) were measured. The preganglionic distance from the caudal axilla point (AP) of the spinal nerve root and the center point (CG) of the spinal ganglion in the intervertebral foramen were determined.
  
  
  RESULTS
  The AP-CG distance increased gradually in the caudal direction from L1 (7.25 ± 2.72 mm right side, 7.30 ± 2.85 mm left side) to a maximum for L5 (16.00 ± 3.39 mm right side, 16.50 ± 3.58 mm left side, p< 0.05). We found a significant reduction for S1 (14.88 ± 3.42 mm right side, 13.83 ± 2.47 mm, p< 0.05). In contrast the DP-AP distances showed a maximum for L1 (12.75 ± 2.78 mm right side, 13.70 ± 3.87 mm left side) with an increasing shortening in the caudal direction and even negative values for S1 (-2.63 ± 3.31 mm right side, -0.83 ± 2.84 mm left side, p< 0.01).
  
  
  CONCLUSIONS
  The topographical anatomy changes each lumbar segment and demands therefore an exact preoperative planning using this specific knowledge to perform a successful microscopic spine surgery. The results of the study support a better understanding of the relevant anatomy and help to reduce incomplete herniated disc removal and to avoid surgical complications.
authors.affiliation: Department of Orthopaedics, Ruhr-University Bochum, Bochum, Germany.
authors.forename: Wolfram
authors.initials: W
authors.lastname: Teske
authors.affiliation: Institute for Spine Research, Bochum, Germany.
authors.forename: Redouane
authors.initials: R
authors.lastname: Boudelal
authors.affiliation: Institute for Spine Research, Bochum, Germany.
authors.forename: Sonja
authors.initials: S
authors.lastname: Zirke
authors.affiliation: Department of Orthopaedics, Ruhr-University Bochum, Bochum, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: von Schulze Pellengahr
authors.affiliation: Institute for Spine Research, Bochum, Germany.|Royal Orthopaedic Hospital Birmingham, Birmingham, UK.
authors.forename: Matthias
authors.initials: M
authors.lastname: Wiese
authors.affiliation: Department of Orthopaedics, Ruhr-University Bochum, Bochum, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Lahner
mesh_terms: D000368:Aged; D000818:Animals; D002102:Cadaver; D017586:Diskectomy / Q000379:methods*; D017952:Ganglia, Invertebrate / Q000033:anatomy & histology; D006801:Humans; D007403:Intervertebral Disc / Q000033:anatomy & histology*; D008159:Lumbar Vertebrae / Q000033:anatomy & histology*; D008161:Lumbosacral Region / Q000033:anatomy & histology*; D008875:Middle Aged; D013126:Spinal Nerve Roots / Q000033:anatomy & histology; D013127:Spinal Nerves / Q000033:anatomy & histology*
keywords: Preganglionic lumbar nerve roots; disc herniation; microscopic lumbar spine surgery