Level Check Technique in Posterior Cervical Surgery

Introduction: It is common practice in spine surgery to do flouroscopic level check. As per the University Hospital Birmingham and SBNS guidelines we should do three level checks in a posterior cervical surgery. First level check preoperatively when a needle/K-wire is used to check the level. Second level check should be done with artery forcep to to spinous process(SP)/lamina/interspinous ligament(ISL). Final check for confirmation of decompression level and implant position. C2 vertebra should be taken as reference in all imaging. In this study we aim to investigate the adherence to the level check techniques and to evaluate any complications arising as a result of non-adherence.

Methods: • Data from Medical informatics for all posterior cervical cases from 1st Oct 2023 to 1st July 2024
• Pre-operative, intra-operative and post-operative imaging reviewed on PACS
• Imaging correlated with post-operative notes
• Data collected:
Pre-operative check –Needle/Kwire
Intra-operative check –SP/Lamina/ISL
Post-operative Check –Yes/No
Complications-Adverse/Serious

Results: • Total number of cases=59
• Pre-operative check done in 53, intra-operative in 58 and post-operative XR done in 34 patients.
• Pre-operative XR: Needle was used in 40 cases and K-wire in 12 cases. A Mcdonald dissector was used in 1 case.
• Intra-operative XR: SP was used in 26, ISL in 24 and lamina in 4 patients. (Drill on lamina= 4, Suction on lamina= 1, Mcdonalds under lamina=2, Clip on Lamina= 1)
• There were two complications reported. One patient had dural tear/CSF leak (adverse). The second had post-operative quadriparesis as a result of cervical cord being pinched with artery forceps(serious). Both complications occurred during intra-operative XR check via ISL approach.

Conclusion : We conclude that ISL is not a safe landmark for intra-operative level check and can cause serious complications. Bone should always be your friend in these cases and we should opt for spinous process as a landmark. This should be considered in the guidelines governing the spinal surgical practice.