title: Gait abnormality due to spinal instability after lumbar facetectomy in the rat.
abstract: OBJECTIVE
  Spinal instability of the lumbar spine causes various clinical symptoms. Among them, spinal instability is thought to contribute to low back pain, but the pathophysiological mechanisms are controversial. Although experimental animal models of spinal instability have been reported, it is unknown whether these models produce pain and whether spinal instability affects walking ability. We used the CatWalk system to investigate whether lumbar facetectomy causes gait abnormalities and low back pain.
  
  
  METHODS
  Thirty male Sprague-Dawley rats were divided into three experimental groups. In the sham group, only the bilateral L4-L5 facet joints were exposed. In the experimental group, rats underwent complete resection of the bilateral L4-L5 facet joints without neural tissue injury. The control group comprised naïve rats. The CatWalk system was used to analyze gait in postoperative weeks 3, 4.5, 6, and 7. Radiological and histological analyses were also performed.
  
  
  RESULTS
  At 7 weeks postoperatively, the rats in the experimental group showed the gait abnormalities seen in low back pain and neuropathic pain models. Radiological examination of the same rats revealed spinal instability with histological evidence of intervertebral disc degeneration.
  
  
  CONCLUSIONS
  These results suggest that spinal instability and/or intervertebral disc degeneration induce gait abnormalities and low back pain. This experimental model may be useful for elucidating the mechanisms underlying clinical symptoms, such as low back pain, in patients with spinal instability.
authors.affiliation: Spine Care Center, Wakayama Medical University Kihoku Hospital, 219, Myouji, Katsuragicho, Ito Gun, Wakayama, Japan, yumeka18@ares.eonet.ne.jp.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Fukui
authors.forename: Mamoru
authors.initials: M
authors.lastname: Kawakami
authors.forename: Munehito
authors.initials: M
authors.lastname: Yoshida
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Nakao
authors.forename: Toshiko
authors.initials: T
authors.lastname: Matsuoka
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yamada
mesh_terms: D000818:Animals; D005684:Gait; D055959:Intervertebral Disc Degeneration / Q000473:pathology / Q000503:physiopathology*; D007593:Joint Instability / Q000503:physiopathology*; D017116:Low Back Pain / Q000503:physiopathology*; D008159:Lumbar Vertebrae / Q000601:surgery*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D021801:Zygapophyseal Joint / Q000601:surgery*