Spine (Phila Pa 1976). 2021 Oct 4. doi: 10.1097/BRS.0000000000004246. Online ahead of print.
ABSTRACT
STUDY DESIGN: A prospective, multicenter study.
OBJECTIVE: To evaluate the usefulness of transcranial motor-evoked potentials (Tc-MEPs) during supine-to-prone position change for thoracic ossification of the posterior longitudinal ligament (T-OPLL).
SUMMARY OF BACKGROUND DATA: Supine-to-prone position change might be a risk of spinal cord injury in posterior decompression and fusion surgeries for T-OPLL.
METHODS: The subjects were 145 patients with T-OPLL surgically treated with posterior decompression and fusion using Tc-MEPs in 14 institutes. Tc-MEPs were monitored before surgery from supine-to-prone position and intraoperatively in 7 institutes and only intraoperatively in the other 7 institutes because of disapproval of the anesthesia department. In cases of Tc-MEP alert after position change, we adjusted the cervicothoracic posture. When the MEP did not recover, we reverted the position to supine and monitored the Tc-MEPs in supine position.
RESULTS: There were 83 and 62 patients with/without Tc-MEP before position change to prone (group A and B). The true-positive rate was lower in group A than group B, but without statistical significance (8.4% vs 16.1%, p = 0.12). In group A, 5 patients who had Tc-MEP alert during supine-to-prone position change were all female and had larger body mass index values and upper thoracic lesions. Among the patients, 3 underwent surgeries after cervicothoracic alignment adjustment, and 2 had postponed operations to 1 week later with halo-vest fixation because of repeated Tc-MEP alerts during position change to prone. The Tc-MEP alert at exposure was statistically more frequent in group B than in group A (p = 0.033).
CONCLUSION: Tc-MEP alert during position change is an important sign of spinal cord injury due to alignment change at the upper thoracic spine. Tc-MEP monitoring before supine-to-prone position change was necessary to prevent spinal cord injury in surgeries for T-OPLL.Level of Evidence: 4.
PMID:34610608 | DOI:10.1097/BRS.0000000000004246
