A novel technique to develop thoracic spinal laminectomy and a methodology to assess the functionality and welfare of the contusion spinal cord injury (SCI) rat model.

Harikrishnan V S,Lissy K Krishnan,Klas S P Abelson,Kimberly R Byrnes

doi:10.1371/journal.pone.0219001

Abstract

This study reports the advantage of a novel technique employing a motorised dental burr to assist laminectomy over the conventional manual technique at T10-T11 vertebra level in a rat model of spinal cord injury. Twenty-four female rats were randomly assigned to four groups: (1) conventionally laminectomised, (2) dental burr assisted laminectomised, (3) conventionally laminectomised with spinal cord contusion and (4) dental burr assisted laminectomised with spinal cord contusion. Basso Beattie Bresnahan (BBB) score, postoperative body weights, rat grimace scale (RGS), open cage activity and rearing was studied at 1, 7, 14, 21 and 28 days postoperatively, and area of spinal tissue affected was evaluated histologically. Laminectomised and spinal cord injured rats from dental burr groups showed significantly more weight gain and less weight loss respectively in comparison with respective conventionally laminectomised groups at various time points. Significantly higher RGS score was noticed in conventionally laminectomised animals on Day 1 in comparison to burr assisted laminectomy and presence of pain was evident until Day 7 in the conventionally spinal cord injured group. BBB score did not differ between techniques, whereas laminectomy groups showed more resting time than spinal injury groups. High rearing score was significantly higher in groups which underwent dental burr assisted technique at various time points with respect to their conventional counterparts. This study suggests that the use of dental burr assisted technique to perform laminectomy will bring refinement by producing less pain, aiding in better recovery, removing procedural artefacts without affecting the outcome of the model.

Highlights

Spinal cord injury (SCI) research predominantly focuses on pathogenesis and development of treatment modalities and to hasten the recovery of patients
Even though many devices and modified techniques have been introduced for spinal fixation and for inducing the SCI, such as NYU/MASCIS (New York University, Multicenter Animal Spinal Cord Injury Study) impactor and OSU (Ohio State University electromagnetic spinal cord injury device) impactor [9] there are no validated studies on alternative techniques that could be of potential advantage over the conventional technique to create the spinal laminectomy
Laminectomy in rodents could cause unintended trauma to the spinal cord, especially towards the anterior part of the axial skeleton where the vertebrae are in close proximity to the failed cord, which could be a cause for potential intervention to the study design

Summary

Introduction

Spinal cord injury (SCI) research predominantly focuses on pathogenesis and development of treatment modalities and to hasten the recovery of patients. Laminectomy in rodents could cause unintended trauma to the spinal cord, especially towards the anterior part of the axial skeleton where the vertebrae are in close proximity to the failed cord, which could be a cause for potential intervention to the study design. This could be a cause of concern where multiple surgeries are continuously carried out as part of study design where the surgeon solely depends upon manual skills and non-motorised equipment to perform laminectomy. The complications are of such magnitude that they can be used modeling conditions like Failed Back Syndrome [10] and arachnoiditis [11]

Objectives

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Conclusion