Introduction: Evidence presented by the Surgical Timing of Acute Spinal Cord Injury Study (STASCIS) was in favor of early (within 24 hours) spinal cord decompression in aimed at improved outcome. The exact definition of decompression and the most favorable surgical technique suitable to offer circumferential release of the subarachnoid space around a swollen spinal cord across several motion segments is however unknown. We compared pre and postoperative CT and MRI images and crossed them against the surgical technique used in order to define the surgical techniques offering the best decompressive capability.

Methods: Pre- and post-operative CT and MRI images of 52 patients with traumatic subaxial cervical spinal cord injury AIS grades A, B, or C and evidence of continued spinal cord compression spanning a 4 year period were compared. A regression analysis was performed to define superior surgical techniques for circumferential spinal cord decompression along 3-5 cervical spinal cord segments.

Results: The mean age was 37.9 (SD=18.6) and the mean ASIA motor score was 16.7 (SD=13.7). The ASIA Impairment Scale was A in 33 (63.5%) patients, B in 15 (28.8%) patients and C in 4 (7.7%) patients. The Allen’s mechanistic classification was distractive in 33 patients and compressive in 18 patients. The mean mid-sagittal diameter of the cervical spine on CT was 13.3 millimeters and the mean intramedullary volume of signal change on MRI images was 1536.4 cubic millimeters. The mean Subaxial Injury Classification Severity (SLIC) score was 8.6. Anterior discectomy or corpectomy was performed in 29 (55.8%) patients and laminectomy ± discectomy or corpectomy was performed in 23 (44.2%) patients. An anterior approach failed to provide a complete decompression of the spinal cord in 51% of cases, but an added laminectomy achieved full decompression in 87% of cases. From 11 demographic, clinical, and injury severity variables, only laminectomy correlated significantly with adequate surgical decompression (p < 0.002).

Conclusions: Conclusions: In traumatic subaxial cervical spine injuries, the inclusion of laminectomy in the surgical approach offered a significantly better chance of spinal cord decompression than pure discectomy or corpectomy.

Patient Care: The concept of earlier surgical decompression of a swollen spinal cord is gaining more traction and momentum in the neurosurgical and orthopedic community. Decompression within the first 24 hours of injury is the only management strategy we have in order to halt or slow down secondary injury. Knowing that decompression does not primarily mean realignment of the spinal column and we need MRI proof of spinal cord decompression is a major scientific step towards appropriate patient care and improved outcome.

Learning Objectives: 1- Spine surgeons often assume that in patient with cervical spine fracture dislocations and MRI evidence of spinal cord compression, closed or open reduction and internal or external fixation are synonymous with spinal cord decompression. Added to the general view is the impression that discectomy or corpectomy are definitive answers to decompression of a swollen spinal cord. In several recent studies such as Fehlings et al (PLoSone V:7, issue 2, e 32037 2/2012), Papadopoulos et al (J Trauma 52:323, 2002) and Vaccaro et al (Spine, 22: 2609, 1997) with preoperative MRI evidence of spinal cord compression only a significant minority of their patients had laminectomy as an adjunct to the surgical decompression and in none of those studies there was adequate postoperative imaging studies as the proof of spinal cord decompressed after surgery. It is clear that if the spinal cord is not decompressed after closed or open reduction, discectomy or corpectomy, how can we be sure that the procedure has been adequate. One of our learning objectives is to add laminectomy to any surgical procedure in order to decompress the spinal cord across several segments and mitigate the secondary insult incurred on spinal cord with continued compression. 2-A second learning objective is to help orthopedic and neurosurgeons understand that realignment with internal or external fixation even with or without discectomy or Corpectomy may not decompress a swollen spinal cord adequately. We therefore recommend postoperative imaging studies (preferably MRI) in order to have evidence that continued spinal cord compression is interrupted which is one step towards mitigating the deleterious effects of secondary injury. 3-We recommend that future prospective studies evaluating the clinical effect of decompression on functional outcome following spinal cord injury be monitored by pre and postoperative MRI as evidence of complete spinal cord decompression.

References: Fehlings MG et al: Early versus delayed decompression of traumatic cervical spinal cord injury: results of the Surgical Timing in Acute Spinal Cord Injury Study (STASCIS). PLoS One 7: e32037, 2012