title: Irregular Alteration of Facet Orientation in Lumbar Segments: Possible Role in Pathology of Lumbar Disc Herniation in Adolescents.
abstract: BACKGROUND
  The role of the overall structural feature of facet joint in the development of lumbar disc herniation (LDH) is unclear. The present study aimed to investigate the role of irregular alteration of facet orientation (IAFO) in low lumbar segments in the pathology of LDH in adolescents.
  
  
  METHODS
  Sixty-five adolescents with LDH were included in the study. Facet angles were measured in magnetic resonance imaging. The IAFO was defined as the irregular orientation of the included facet joints angle, which was regularly increased from L3 to S1 in the normal group, including small-large-small (SLS) type, large-small-large (LSL) type, and large-small-smaller (LSS) type. Thirty normal adolescents without lumbar lesions were selected into the control group. Statistical analysis was performed using χ(2) test.
  
  
  RESULTS
  IAFO was observed in 20 of 65 subjects in LDH group compared with 3 of 30 in the control group [P = 0.038; OR=4 (1.086, 14.735)]. The SLS type was observed in 14 patients, and the LSL type was found in 6 patients, compared with 2 and 1, respectively, in the control group, no LSS type was found in the two groups. There were 8 subjects with IAFO of SLS style herniated in L5/S1 level compared with 6 subjects in L4/5. There was 1subject with IAFO of LSL style herniated in L5/S1 level compared with 5 subjects in L4/5.
  
  
  CONCLUSIONS
  The findings of this study suggest that the IAFO in the lumbar spine was associated with lumbar disc herniation in adolescents.
authors.affiliation: Department of Orthopedics, Xinqiao Hospital, Third Military Medical University, China.
authors.forename: Honggang
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Orthopedics, Xinqiao Hospital, Third Military Medical University, China.
authors.forename: Zhengfeng
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Department of Orthopedics, Xinqiao Hospital, Third Military Medical University, China. Electronic address: Happyzhou_vip@163.com.
authors.forename: Yue
authors.initials: Y
authors.lastname: Zhou
mesh_terms: D000293:Adolescent; D002648:Child; D005260:Female; D006801:Humans; D007405:Intervertebral Disc Displacement / Q000473:pathology* / Q000601:surgery; D008159:Lumbar Vertebrae / Q000002:abnormalities / Q000473:pathology* / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008297:Male; D019635:Neurosurgical Procedures / Q000379:methods; D055815:Young Adult; D021801:Zygapophyseal Joint / Q000002:abnormalities / Q000473:pathology* / Q000601:surgery
keywords: Adolescents; Facet joint; Facet tropism; Lumbar disc herniation; Magnetic resonance imaging