Atraumatic Spine Distraction Induces Metabolic Distress in Spinal Motor Neurons

Abstract

Corrective forces during spine deformity surgery, including distraction, impart significant stresses to the spinal cord that may result in permanent injury. Intraoperative neuromonitoring is commonly used by surgeons to recognize possible damage to the spinal cord in cases of evident traumatic or vascular damage to the spinal cord. However, mild insult to the spinal cord that does not result in obvious trauma or electrophysiological changes present a major clinical challenge as the mechanisms of this type of spinal cord injury (SCI) remain largely unknown, and thus preventive strategies are lacking. We used a sustained bidirectional spinal distraction animal model to determine the role of stretch-induced hypoxia in mild SCI. Direct measurement of intraparenchymal oxygen revealed an immediate decrease in partial pressure (47.08 ± 5.79% pO) distal to the injury site following a 5-mm distraction. This hypoxic insult induced mitochondrial dysfunction as evidenced by an acute increase (216%) in protein oxidation 30 min post-injury, as well as a 37% decrease in perikaryal size and a 42% decrease in nuclear area (pyknosis) in ventral motor neurons at the injury site. These results indicate that hypoxic events during mild spine distraction may lead to cellular metabolic impairments and permanent functional deficits. The development of strategies targeting the prevention of hypoxic injury during spine distraction may be useful in protecting the cellular metabolic damage that may occur during spine surgery in the absence of overt mechanical or vascular SCI.

Investigation of in vivo three‐dimensional changes of the spinal canal after corrective surgeries of the idiopathic scoliosis

“…In contemporary corrective surgeries of scoliosis, the intraoperative neurological damage of the axial spinal cord has been found at different locations across the spinal cord cross section, 15 and SSEPs always showed unilateral spectrum deteriorations 18,26 . SCI was found not simply in the center location of the cord.…”

Elucidating the Potential Mechanisms Underlying Distraction Spinal Cord Injury-Associated Neuroinflammation and Apoptosis

“…With regard to the model establishment approach of DSCI, computer-controlled stepping motor, distraction apparatus, and global column osteotomy with continuous distraction (GOCD) are the most common methods used in different animals ( Chen et al, 2016 ; Wu et al, 2016 ; Bell et al, 2017 ; Wu et al, 2017 ; Shimizu et al, 2018 ; Tica et al, 2018 ; Guo et al, 2019 ; Wang J et al, 2019 ). From bench to bedside, severe spinal deformities can be treated by global column osteotomy techniques using an anterior, posterior, or a hybrid approach ( Zhou et al, 2011 ).…”

“…With the application of the growing rod ( Helenius et al, 2018 ) and the appearance of vertebral column resection osteotomy ( Yang et al, 2016 ) in patients with severe deformities, the incidence of DSCI remains higher than that in the past few decades. Since DSCI was first reported in the 1970s ( Martin et al, 1971 ; Fried, 1974 ), several clinical studies have focused on stretching-induced SCI and established relevant animal models using mice and rabbits ( Wu et al, 2016 ; Bell et al, 2017 ; Tica et al, 2018 ; Guo et al, 2019 ). However, currently, a suitable DSCI model that mimics clinical DSCI and can be used to study the cytological and molecular mechanisms underlying DSCI is still unavailable.…”

Does Navigation Make Spinal Fusion for Adolescent Idiopathic Scoliosis Safer? Insights From a National Database

“…2,4 Posterior pedicle screws have become the preferred anchor construct in SF for its stability, high rate of fusion, and ability to achieve triplanar correction. [18][19][20][21] However, SF carries inherent risks, both because curve correction can result in stretch-induced hypoxia across watershed areas of the spinal cord 22 and because inappropriate pedicle screw placement can lead to injury to adjacent neurological and vascular structures, as well as pneumothorax. 23,24 In particular, in large curves, the spinal cord is draped along the concave side, in close proximity to the path of the pedicle screw; therefore, even a slightly malpositioned screw can lead to catastrophic consequences.…”