Resection of spinous processes can cause spinal cord injury in patient with ossification of the posterior longitudinal ligament in the thoracic spine.

Abstract

Case report. To report intraoperative spinal cord injury by resection of spinous processes in a 73-year-old man with ossification of the posterior longitudinal ligament (OPLL) in the thoracic spine. A 73-year-old man presented with cervicothoracic OPLL with bilateral numbness and clumsiness of his hand, weakness of his lower extremities and severe gait disturbance. His Japanese Orthopaedic Association (JOA) score was 7.5 out of 17. Cervical laminoplasty (C2-6), cervicothoracic laminectomy (C7-T10) and posterior fusion (C7-T10) were performed in the prone position with electrophysiologic monitoring of the spinal cord-evoked potentials (SCEPs). The spinal processes with supra- and interspinous ligaments between C7 and T10 were resected. After resection, the amplitude of SCEP waveforms decreased rapidly to <10% of control levels. Laminectomy was performed, and, after 80 min of SCEP deterioration, an instrumented fusion with correction for kyphosis was completed. The SCEP amplitude recovered gradually. Immediately after surgery, the patient suffered severe motor loss in both lower limbs. His neurological recovery progressed gradually from 2 days after surgery, and he was able to walk at 3 months after surgery. At 6 years after surgery, the JOA score was 11. Our results suggest that intraoperative spinal cord injury can occur before posterior decompression by resection of spinal processes with supra- and interspinous ligaments. The timing of the instrumented stabilization using a temporary rod is important and should be considered immediately after posterior exposure of the spine.