title: Three-dimensional micro-computed tomography analysis for spinal instability after lumbar facetectomy in the rat.
abstract: Intervertebral disc degeneration is thought to contribute to low back pain. However, the pathophysiological mechanisms remain controversial. In a previous study, we developed an animal model that showed delayed gait disturbance after lumbar facetectomy in the rat. We believe that this gait disturbance was caused by low back pain, although the mechanisms of this gait abnormality remain unknown. The purpose of this study was to evaluate structural changes of the lumbar spine after facetectomy in the rat utilizing three-dimensional micro-computed tomography (3DμCT) compared to histology.
  
  
  
  Thirty male SD rats were divided into three groups. In the Sham group (n = 13), only exposure of bilateral facet joints at the L4-5 level was performed. In the Experimental group (n = 13), complete resection of bilateral L4-5 facet joints was achieved. Naïve rats (n = 4) were used for controls. At 7-week postoperative, 3DµCT and histological analyses were performed.
  
  
  
  On 3DµCT images, increased disc height and endplate irregularities at the L4-5 segment and decreased disc height at adjacent segments were observed in the Experimental group. Histological scores were also higher in the Experimental group than the Sham Group.
  
  
  
  Degenerative changes were observed at the facetectomy level. These may correspond with the previously reported delayed gait disturbance after facetectomy. This animal model may be useful to create mechanically induced disc degeneration without direct tissue damage to the disc.
authors.affiliation: Spine Care Center, Wakayama Medical University Kihoku Hospital, 219, Myouji, Katsuragicho, Ito Gun, Wakayama, Japan. taiga26@zeus.eonet.ne.jp.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Fukui
authors.affiliation: Spine Care Center, Wakayama Medical University Kihoku Hospital, 219, Myouji, Katsuragicho, Ito Gun, Wakayama, Japan.
authors.forename: Mamoru
authors.initials: M
authors.lastname: Kawakami
authors.affiliation: Department of Orthopaedic Surgery, School of Medicine, University of California, 9500 Gilman Dr. MC0863, La Jolla, San Diego, CA, USA.
authors.forename: Kevin
authors.initials: K
authors.lastname: Cheng
authors.affiliation: Department of Orthopaedic Surgery, School of Medicine, University of California, 9500 Gilman Dr. MC0863, La Jolla, San Diego, CA, USA.
authors.forename: Koichiro
authors.initials: K
authors.lastname: Murata
authors.affiliation: Department of Orthopaedic Surgery, School of Medicine, University of California, 9500 Gilman Dr. MC0863, La Jolla, San Diego, CA, USA.
authors.forename: Keianne
authors.initials: K
authors.lastname: Yamada
authors.affiliation: Department of Orthopaedic Surgery, School of Medicine, University of California, 9500 Gilman Dr. MC0863, La Jolla, San Diego, CA, USA.
authors.forename: Rinoka
authors.initials: R
authors.lastname: Sato
authors.affiliation: Department of Orthopaedic Surgery, Wakayama Medical University, 811-1, Kimiidera, Wakayama City, Wakayama, Japan.
authors.forename: Munehito
authors.initials: M
authors.lastname: Yoshida
authors.affiliation: Department of Orthopaedic Surgery, Wakayama Medical University, 811-1, Kimiidera, Wakayama City, Wakayama, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yamada
authors.affiliation: Department of Orthopedic Surgery, Rush University Medical Center, 1611 W. Harrison St., Chicago, IL, USA.
authors.forename: Nozomu
authors.initials: N
authors.lastname: Inoue
authors.affiliation: Department of Orthopaedic Surgery, School of Medicine, University of California, 9500 Gilman Dr. MC0863, La Jolla, San Diego, CA, USA.
authors.forename: Koichi
authors.initials: K
authors.lastname: Masuda
mesh_terms: D000818:Animals; D005684:Gait; D021621:Imaging, Three-Dimensional; D055959:Intervertebral Disc Degeneration / Q000000981:diagnostic imaging* / Q000209:etiology / Q000473:pathology / Q000503:physiopathology; D007593:Joint Instability / Q000000981:diagnostic imaging* / Q000209:etiology / Q000473:pathology / Q000503:physiopathology; D017116:Low Back Pain / Q000000981:diagnostic imaging* / Q000209:etiology / Q000473:pathology / Q000503:physiopathology; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D055114:X-Ray Microtomography / Q000379:methods; D021801:Zygapophyseal Joint / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*
keywords: Intervertebral disc degeneration; Low back pain; Lumbar facetectomy; Spinal instability; Three-dimensional micro-computed tomography