title: Anatomical parameters of fifth lumbar vertebra in L5-S1 spondylolytic spondylolisthesis from a surgical point of view.
abstract: OBJECTIVE
  We measured the length, width, height, and angles related to both Meyerding grading system and Marchetti-Bartolozzi classification in L5-S1 spondylolytic spondylolisthesis patients to investigate the anatomical characteristics of fifth lumbar pedicles.
  
  
  METHODS
  Seventy patients with L5-S1 spondylolytic spondylolisthesis and general spinal disease were included. Patient attributes, Meyerding grading system and Marchetti-Bartolozzi classification of spondylolisthesis, length, width, height of L4 and L5 pedicle, and the angle between pedicle and vertebral midline were measured. The heights of L5 vertebral body, divided as anterior, mid, and posterior were also measured.
  
  
  RESULTS
  The pedicle is elongated and the angle of the pedicle is wider in cases of L5-S1 spondylolysis. Vertebral body shape was more posteriorly wedged in L5-S1 spondylolysis. Pedicles were more narrow and shorter in L5-S1 spondylolysis.
  
  
  CONCLUSIONS
  In L5-S1 spondylolytic spondylolisthesis, a longer screw is suitable for insertion of L5 pedicle and the screw should be inserted more medially compared to patients without spondylolysis.
authors.affiliation: Department of Neurosurgery, Gangnam Severance Hospital, Spine and Spinal Cord Institute, Yonsei University College of Medicine, 712, Eonjuro Gangnam-gu, Seoul, 135-720, Korea.
authors.forename: Hong-June
authors.initials: HJ
authors.lastname: Choi
authors.forename: Jeong-Yoon
authors.initials: JY
authors.lastname: Park
authors.forename: Dong-Kyu
authors.initials: DK
authors.lastname: Chin
authors.forename: Keun-Su
authors.initials: KS
authors.lastname: Kim
authors.forename: Yong-Eun
authors.initials: YE
authors.lastname: Cho
authors.forename: Sung-Uk
authors.initials: SU
authors.lastname: Kuh
mesh_terms: D059925:Anatomic Landmarks; D001863:Bone Screws; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000033:anatomy & histology* / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011859:Radiography; D012447:Sacrum / Q000033:anatomy & histology* / Q000000981:diagnostic imaging / Q000601:surgery*; D012720:Severity of Illness Index; D013168:Spondylolisthesis / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery*; D013169:Spondylolysis / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery