Bourget-Murray Jonathan, Bassi Mahdi, Frederick Ariana, Hines Jerod, Jarzem Peter F
McGill University Health Center, Orthopedic Research Laboratory, McGill University, Montreal, Canada.
Department of Orthopedic Surgery, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.
J Craniovertebr Junction Spine. 2017 Apr-Jun;8(2):108-112. doi: 10.4103/jcvjs.JCVJS_25_17.
Spinal cord compression is a known cause of spinal cord injury. The purpose of this study is to measure pressure response during graded spinal cord compression. This information will be important in evaluating the amount of canal compromise that can be tolerated before risking neurological injury secondary to cord compression. To date, there is no published study that has evaluated pressure response to graded canal compromise in the thoracic and lumbar spine.
A comparative biomechanical investigation using an burst fracture model of graded spinal canal compromise was performed. Four porcine spines, sectioned into four thoracics and four lumbar segments, were harvested from 30 kg pigs. Graded spinal canal compromise (0.75 mm/30 s) was achieved using a modified 12.7 mm dynamic hip screw. The real-time ventral epidural pressure was measured at each 0.75 mm of canal compromise.
A significant increase in spinal cord pressure was recorded during graded spinal cord compression ( < 0.0001), and there were no statistical differences between the increase in pressure measured in the thoracic and lumbar spinal segments ( = 0.83). The pressure to degree of canal compromise curve exhibited an initial rapid rise in pressure followed by incrementally smaller increases in pressure as canal compromise increased.
Spinal cord pressure increased with any degree of canal compromise, the most important rise occurring with initial compression. Future studies will evaluate the usefulness of laminectomy to completely restore ventral epidural pressure in the thoracic and lumbar spine.
脊髓受压是脊髓损伤的已知原因。本研究的目的是测量分级脊髓受压过程中的压力反应。这些信息对于评估在因脊髓受压继发神经损伤的风险之前能够耐受的椎管狭窄程度至关重要。迄今为止，尚无已发表的研究评估胸腰椎分级椎管狭窄时的压力反应。
采用分级椎管狭窄爆裂骨折模型进行了一项对比生物力学研究。从30千克的猪身上获取4个猪脊柱，将其切成4个胸段和4个腰段。使用改良的12.7毫米动力髋螺钉实现分级椎管狭窄（0.75毫米/30秒）。在椎管狭窄每0.75毫米时测量实时腹侧硬膜外压力。
在分级脊髓受压期间记录到脊髓压力显著增加（<0.0001），胸段和腰段测量的压力增加之间无统计学差异（=0.83）。椎管狭窄程度与压力曲线显示，压力最初迅速上升，随后随着椎管狭窄增加压力上升幅度逐渐减小。
任何程度的椎管狭窄都会使脊髓压力增加，最重要的上升发生在初始受压时。未来的研究将评估椎板切除术在完全恢复胸腰椎腹侧硬膜外压力方面的有效性。
