title: A rabbit model of lumbar distraction spinal cord injury.
abstract: Excessive spinal distraction is a major cause of distraction spinal cord injury (SCI) during spinal deformity correction surgery. However, the lack of animal models of gradable and replicable distraction SCI has hampered research about how it occurs and how it can be prevented. The rabbit is a suitable choice for a model because it is more similar to humans than the rat, the most often used for studies of distraction SCI. The rabbit is readily acquired and reasonably affordable to maintain.
  
  
  
  The study aims to develop a gradable and replicable animal model of human lumbar distraction SCI.
  
  
  
  This is an animal laboratory study.
  
  
  
  We built a spine distractor designed to vary the percentage of spine distraction by changing the movement between the bony landmarks of the spine. Anesthetized rabbits underwent surgery to expose the vertebral segments from T12 through L4. The distractor was mounted onto the T12 and L4 vertebral segments, and distraction was effected by turning the distractor's central screw to 0% (control), 10%, 20%, or 30% of the length from the L1 to the L4 vertebral segments, with eight rabbits in each group. Cortical somatosensory evoked potentials were recorded, and neurologic function was evaluated before the distractor was mounted and after the distractor was dismounted. The rabbits were killed, and spinal cord samples were taken for biochemical, histopathologic, and stereologic studies.
  
  
  
  With increasing percentage distraction, the extent of distraction SCI increased as measured by recordings of cortical somatosensory evoked potentials, neurologic function, and biochemical, histopathologic, and stereologic studies.
  
  
  
  Our model can be widely applied to studies of the causes of and treatment for distraction SCI.
authors.affiliation: Orthopedic Department, Air Force General Hospital of Chinese People's Liberation Army, No 30 Fucheng Rd, Beijing 100142, China.
authors.forename: Ji
authors.initials: J
authors.lastname: Wu
authors.affiliation: Orthopedic Department, Air Force General Hospital of Chinese People's Liberation Army, No 30 Fucheng Rd, Beijing 100142, China. Electronic address: xuejing.cn@gmail.com.
authors.forename: Jing
authors.initials: J
authors.lastname: Xue
authors.affiliation: Orthopedic Department, Air Force General Hospital of Chinese People's Liberation Army, No 30 Fucheng Rd, Beijing 100142, China.
authors.forename: Rongrong
authors.initials: R
authors.lastname: Huang
authors.affiliation: Orthopedic Department, Air Force General Hospital of Chinese People's Liberation Army, No 30 Fucheng Rd, Beijing 100142, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Zheng
authors.affiliation: Orthopedic Department, Air Force General Hospital of Chinese People's Liberation Army, No 30 Fucheng Rd, Beijing 100142, China.
authors.forename: Yuming
authors.initials: Y
authors.lastname: Cui
authors.affiliation: Orthopedic Department, West China Hospital, Sichuan University, No. 37 Guo Xue Xiang, Chengdu, Sichuan 610041, China.
authors.forename: Shucheng
authors.initials: S
authors.lastname: Rao
mesh_terms: D000818:Animals; D001852:Bone Lengthening / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods; D001863:Bone Screws / Q000009:adverse effects; D004195:Disease Models, Animal; D005073:Evoked Potentials, Somatosensory; D008159:Lumbar Vertebrae / Q000473:pathology; D011817:Rabbits; D013119:Spinal Cord Injuries / Q000209:etiology* / Q000473:pathology
keywords: Animal model; Biochemical study; Cortical somatosensory evoked potentials; Distraction; Histopathologic study; Spinal cord injury; Stereologic study