title: A morphological study of the fibrous capsule of the human lumbar facet joint.
abstract: METHODS
  Macroscopic and microscopic investigations of the human lumbar facet joint capsule were undertaken.
  
  
  OBJECTIVE
  To describe the morphologic characteristics of the fibrous capsule of the lumbar facet joints.
  
  
  BACKGROUND
  Previous biomechanical and neurophysiologic studies by the authors have shown that the lumbar facet joint capsule may be a source of low back pain.
  
  
  METHODS
  Macroscopic investigation was performed on the facet joint capsules dissected from five fresh adult cadavers. For microscopic studies, facet joint capsules obtained from cadaver dissection and spinal surgeries were stained by the hematoxylin and eosin method and the Elastica-Van Gieson method.
  
  
  RESULTS
  The outer layer of the fibrous capsule is a dense regular connective tissue that is composed of parallel bundles of collagenous fibers. The inner layer of the fibrous capsule consists of bundles of elastic fibers, similar to the ligamentum flavum. In the superior and middle part of the joint, the fibers run in the medial to lateral direction, crossing over the joint gap. In the inferior part of the joint, the fibers are relatively long and run in a superior-medial to inferior-lateral direction, covering the inferior articular recess. They are thicker than the layer in the superior and middle parts of the joint.
  
  
  CONCLUSIONS
  Anatomical and histologic features of the lumbar facet joint capsule are different between its outer layer and inner layer. This complex of morphologic factors can affect the biomechanics and neurophysiology of the lumbar facet joint.
authors.affiliation: Department of Orthopaedic Surgery, Sapporo Medical University, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Yamashita
authors.forename: Y
authors.initials: Y
authors.lastname: Minaki
authors.forename: A C
authors.initials: AC
authors.lastname: Ozaktay
authors.forename: J M
authors.initials: JM
authors.lastname: Cavanaugh
authors.forename: A I
authors.initials: AI
authors.lastname: King
mesh_terms: D000328:Adult; D002102:Cadaver; D003094:Collagen / Q000032:analysis; D003238:Connective Tissue / Q000033:anatomy & histology*; D004547:Elastic Tissue / Q000033:anatomy & histology; D005347:Fibroblasts / Q000166:cytology; D006801:Humans; D017746:Joint Capsule / Q000033:anatomy & histology*; D008159:Lumbar Vertebrae / Q000033:anatomy & histology*; D008875:Middle Aged
chemical_list: D003094:Collagen