title: Lumbar juxta-facet joint cysts in association with facet joint orientation, -tropism and -arthritis: A case-control study.
abstract: OBJECTIVE
  To assess the association between juxta-facet-joint cysts (JFC) occurrence at the lumbar spine and Facet Joint (FJ) orientation, -tropism and -arthritis.
  
  
  METHODS
  Study group, 36 consecutive patients with JFC and the same number of controls, with degenerative diseases without JFC were match paired for demographics and spine segment. Parameter assessment was by T2-weighted axial MRI scans. JFC diagnosis was confirmed histopathologically. Group comparison was by Student's t-test for continuous variables and X(2) for categorical variables.
  
  
  RESULTS
  Nineteen female and 17 male patients, aged between 45 and 85 years (mean 67.19 ± 10.3 years) had a mean JFC size of 9.26 ± 4.8mm occurring most frequently in the segment L4-L5 (75% n=25) and on the left side (61%). Mean FJ orientation of the study group was significantly more coronal compared to controls (left side 42° vs 36°, p<0.02*, 95% confidence interval: 0.9-11.5 and right side 43° vs 37°, p<0.02*, 95% confidence interval: 0.6-10.6 respectively). However, individual intersegmental analysis for study group patients showed the JFC bearing side to be significantly more sagittally oriented 40° ± 11.2° compared to 45° ± 13.2° for the side without FJC (p<0.03*, 95% confidence interval: 8.1-1.7). 50% of the study group showed FJ asymmetry compared to 30% in controls, with a trend for FJ tropism (p<0.07). Severe (grade 3) FJ arthritis was significantly more predominant in the study group 23/33 (p<0.001*) as compared to controls.
  
  
  CONCLUSIONS
  Compared to a control group, JFC occurrence is associated with significant higher rates of arthritis and coronally orientated FJ. At intersegment comparison within the same patient cysts located in more sagittally orientated FJ and the asymmetric segments show a trend for FJ tropism.
authors.affiliation: Department of Neurosurgery, University Medical Center Langendreer, Ruhr-University-Bochum, Bochum, Germany. Electronic address: genevieve.ening@gmail.com.
authors.forename: Genevieve
authors.initials: G
authors.lastname: Ening
authors.affiliation: Department of Radiology and Neuroradiology, University Medical Center Langendreer, Ruhr-University-Bochum, Bochum, Germany.
authors.forename: Annika
authors.initials: A
authors.lastname: Kowoll
authors.affiliation: Institute of Pathology, Ruhr-University Bochum, Bochum, Germany.
authors.forename: Ingo
authors.initials: I
authors.lastname: Stricker
authors.affiliation: Department of Neurosurgery, University Medical Center Langendreer, Ruhr-University-Bochum, Bochum, Germany.
authors.forename: Kirsten
authors.initials: K
authors.lastname: Schmieder
authors.affiliation: Department of Neurosurgery, University Medical Center Langendreer, Ruhr-University-Bochum, Bochum, Germany.
authors.forename: Christopher
authors.initials: C
authors.lastname: Brenke
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D003560:Cysts / Q000453:epidemiology / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000473:pathology* / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008297:Male; D008866:Microsurgery; D008875:Middle Aged; D055013:Osteoarthritis, Spine / Q000453:epidemiology / Q000473:pathology*; D054850:Osteophyte / Q000453:epidemiology / Q000473:pathology*; D018523:Tropism; D021801:Zygapophyseal Joint / Q000473:pathology* / Q000601:surgery
keywords: Facet-joint arthritis; Facet-joint cysts; Facet-joint orientation; Facet-joint tropism