Role of Intraoperative Disc Contrast Injection in Determining the Segment Responsible for Cervical Spinal Cord Injury without Radiographic Abnormalities

Objective: To determine the features of discs in spinal cord injury without radiographic abnormality (SCIWORA) by intraoperative disc contrast injection (IODCI) and to subsequently treat the responsible discs operatively. Methods: From January 2007 to December 2011, 16 adult cases of cervical SCIWORA were enrolled in this study. The average preoperative Japanese Orthopaedic Association (JOA) score was 9.1 +/- 1.8. Although preoperative imaging showed no obvious fracture or dislocation, spinal cord compression was evident in all cases. High spinal cord signals on MRI T2WI and cervical disc degeneration were present in all cases and swollen soft tissue anterior to the cervical spine in nine cases. All patients underwent anterior cervical surgeries for spinal cord compression, IODCI being performed after exposure of suspicious discs. Patients with only one ruptured disc underwent anterior cervical discectomy and fusion; those with more complex injuries underwent anterior cervical corpectomy and fusion with fixation of the ruptured segment. JOA scores, X-rays and CT scans were checked at specified intervals over an average of 24.4 months. Results: Of 32 discs suspected preoperatively of being injured, 19 were identified as ruptured by IODCI. Anterior annulus fibrosus rupture was proved in 11 patients whereas the anterior longitudinal ligament was intact in all. JOA scores at 2 weeks, 3 months and last follow-up postoperatively were 13.3 +/- 1.5, 14.5 +/- 1.6 and 15.1 +/- 1.5 respectively. The recovery rates were 53.2%, 68.3% and 75.9%, respectively. Conclusion: IODCI helps to determine the segment responsible for cervical SCIWORA.