title: Anatomical study on the relationship between the dorsal root ganglion and the intervertebral disc in the lumbar spine.
abstract: OBJECTIVE
  To describe the location of the dorsal root ganglion in relation to the intervertebral disc, including the "triangular" safety zone for minimally invasive surgery in the lumbar spine.
  
  
  METHODS
  Eight adult cadavers were dissected bilaterally in the lumbar region, using a posterolateral approach, so as to expose the L3L4 and L4L5 spaces, thereby obtaining measurements relating to the space between the intervertebral disc, pedicles cranial and caudal to the disc, path of the nerve root, dorsal ganglion and safety triangle.
  
  
  RESULTS
  The measurements obtained were constant, without significant differences between levels or any laterality. The dorsal ganglion occupied the lateral border of the triangular safety zone in all the specimens analyzed.
  
  
  CONCLUSIONS
  Precise localization of the ganglion shows that the safety margin for minimally invasive procedures is less than what is presented in studies that only involve measurements of the nerve root, thus perhaps explaining the presence of neuropathic pain after some of these procedures.
authors.affiliation: Hospital Universitário Cajuru, Pontifícia Universidade Católica do Paraná, Curitiba, PR, Brazil.
authors.forename: Emiliano
authors.initials: E
authors.lastname: Vialle
authors.affiliation: Hospital Universitário Cajuru, Pontifícia Universidade Católica do Paraná, Curitiba, PR, Brazil.
authors.forename: Luiz Roberto
authors.initials: LR
authors.lastname: Vialle
authors.affiliation: Hospital Universitário Cajuru, Pontifícia Universidade Católica do Paraná, Curitiba, PR, Brazil.
authors.forename: William
authors.initials: W
authors.lastname: Contreras
authors.affiliation: Hospital Universitário Cajuru, Pontifícia Universidade Católica do Paraná, Curitiba, PR, Brazil.
authors.forename: Chárbel
authors.initials: C
authors.lastname: Jacob
keywords: Minimally invasive surgical procedures; Spinal ganglia; Spine/anatomy and histology