Three-dimensional micro-computed tomography analysis for spinal instability after lumbar facetectomy in the rat

• Published in: European spine journal 2017-08, Vol.26 (8), p.2014-2020
• Main Authors: Fukui, Daisuke, Kawakami, Mamoru, Cheng, Kevin, Murata, Koichiro, Yamada, Keianne, Sato, Rinoka, Yoshida, Munehito, Yamada, Hiroshi, Inoue, Nozomu, Masuda, Koichi
• Format: Article
• Language: English
• Subjects: Animals; Back pain; Computed tomography; Degeneration; Gait; Imaging, Three-Dimensional; Intervertebral Disc Degeneration - diagnostic imaging; Intervertebral Disc Degeneration - etiology; Intervertebral Disc Degeneration - pathology; Intervertebral Disc Degeneration - physiopathology; Intervertebral discs; Joint Instability - diagnostic imaging; Joint Instability - etiology; Joint Instability - pathology; Joint Instability - physiopathology; Low back pain; Low Back Pain - diagnostic imaging; Low Back Pain - etiology; Low Back Pain - pathology; Low Back Pain - physiopathology; Lumbar Vertebrae - diagnostic imaging; Lumbar Vertebrae - pathology; Lumbar Vertebrae - physiopathology; Lumbar Vertebrae - surgery; Male; Medicine; Medicine & Public Health; Movement disorders; Neurosurgery; Original Article; Pain; Rats; Rats, Sprague-Dawley; Rodents; Spine (lumbar); Surgical Orthopedics; Tomography; X-Ray Microtomography - methods; Zygapophyseal Joint - pathology; Zygapophyseal Joint - physiopathology; Zygapophyseal Joint - surgery
• ISSN: 0940-6719; 1432-0932
• DOI: 10.1007/s00586-016-4920-7

Purpose 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. Methods 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. Results 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. Conclusions 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.