title: Sagittal plane configuration of the sacrum in spondylolisthesis.
abstract: METHODS
  A radiographic study of the sagittal sacral deformity in spondylolisthesis.
  
  
  OBJECTIVE
  To characterize and classify the pathoanatomy of sagittal sacral deformation in spondylolisthesis.
  
  
  BACKGROUND
  Spondylolisthesis has been extensively described and reviewed in the literature. Deformity of the entire sacrum in spondylolisthesis potentially could affect the natural history, treatment options, and outcome. The sagittal contour of the entire human sacrum has never been quantitatively studied in spondylolisthesis.
  
  
  METHODS
  A literature search was performed and data was gathered retrospectively on patients with spondylolisthesis at the authors' institution. Cases of degenerative spondylolisthesis were excluded. Specifically those patients with L5-S1 spondylolisthesis were studied. The authors studied standing lateral radiographs and performed statistical analysis to understand morphologic relations.
  
  
  RESULTS
  A broad range of global sacral kyphosis (37-188 degrees ) exists in spondylolisthesis. Increasing sacral kyphosis is significantly associated with increasing percent slip, sacral horizontal angle, Neuman's classification, lumbar lordosis, and lumbar index. A simple classification of the spectrum of sacral deformity in the sagittal plane is presented.
  
  
  CONCLUSIONS
  The entire sacrum in spondylolisthesis can develop a significant kyphotic deformity in the sagittal plane, and this is associated with other abnormalities found in the lumbosacral spine. Sacral deformity is a significant factor in the assessment of the sagittal contour of the patient with L5-S1 spondylolisthesis.
authors.affiliation: Department of Orthopaedic Surgery, The George Washington University Medical Center, Washington, DC, USA.
authors.forename: S B
authors.initials: SB
authors.lastname: Antoniades
authors.forename: K W
authors.initials: KW
authors.lastname: Hammerberg
authors.forename: R L
authors.initials: RL
authors.lastname: DeWald
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D005260:Female; D006801:Humans; D007738:Kyphosis / Q000000981:diagnostic imaging*; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011859:Radiography; D012189:Retrospective Studies; D012447:Sacrum / Q000000981:diagnostic imaging*; D013168:Spondylolisthesis / Q000000981:diagnostic imaging*; D018709:Statistics, Nonparametric