title: Lumbar facet joint motion in patients with degenerative spondylolisthesis.
abstract: METHODS
  Controlled laboratory study.
  
  
  OBJECTIVE
  To investigate the in vivo biomechanical effect of degenerative lumbar spondylolisthesis (DLS) on the motion of the facet joint during various functional weight-bearing activities.
  
  
  BACKGROUND
  Although the morphologic changes of the facet joints in patients with DLS have been reported in a few studies, no data have been reported on the kinematics of these facet joints.
  
  
  METHODS
  Ten patients with DLS at L4-L5 were studied. Each patient underwent a magnetic resonance imaging scan to obtain 3-dimensional models of the lumbar vertebrae from L2-L5 and a dual fluoroscopic imaging scan in different postures: flexion-extension, left-right bending, and left-right torsion. The positions of the vertebrae were reproduced by matching the magnetic resonance imaging-based vertebral models to the fluoroscopic images. The kinematics of the facet joint and the ranges of motion were compared with those of healthy subjects and those of patients with degenerative disk diseases (DDD) previously published.
  
  
  RESULTS
  In DLS patients, the range of rotation of the facet joints was significantly less at the DLS level (L4-L5) than that at the adjacent levels (L2-L3 and L3-L4), whereas the range of translation was similar at all levels. The range of rotation at the facet joints of the DLS level decreased compared with those of both the DDD patients and healthy subjects at the corresponding vertebral level (L4-L5), whereas no significant difference was found in the range of translation. The range of motion of facet joints in DLS and in DDD patients was similar at the adjacent levels (L2-L3 and L3-L4).
  
  
  CONCLUSIONS
  The range of rotation decreased at the facet joints at the DLS level (L4-L5) in patients compared with those in healthy subjects and DDD patients. This decrease in range of rotation implies that the DLS disease may cause restabilization of the joint. The data may help the selection of conservative treatment or different surgical techniques for the DLS patients.
authors.affiliation: Bioengineering Laboratory, Department of Orthopaedic Surgery, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA.
authors.forename: Qi
authors.initials: Q
authors.lastname: Yao
authors.forename: Shaobai
authors.initials: S
authors.lastname: Wang
authors.forename: Jae-Hyuk
authors.initials: JH
authors.lastname: Shin
authors.forename: Guoan
authors.initials: G
authors.lastname: Li
authors.forename: Kirkham Burwick
authors.initials: KB
authors.lastname: Wood
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000473:pathology* / Q000503:physiopathology*; D008297:Male; D016059:Range of Motion, Articular; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013168:Spondylolisthesis / Q000473:pathology* / Q000503:physiopathology*; D021801:Zygapophyseal Joint / Q000473:pathology* / Q000503:physiopathology*