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

Abstract

Study design: Case report. Objective: 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. Methods: 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). Results: The spinal processes with supra-and interspinous ligaments between C7 and T10 were resected. After resection, the amplitude of SCEP waveforms decreased rapidly to o10% 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. Conclusion: 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. Spinal Cord (2014) 52, S19-S21; doi:10.1038/sc.2014.151 INTRODUCTIONIn treatment for thoracic ossification of the posterior longitudinal ligament (OPLL), postoperative paraplegia is a major risk. 1,2 To avoid the postoperative paraplegia, posterior decompression with instrumented fusion (PDF) has been reported. 3 However, postoperative paraplegia remains a risk and the causes are controversial. We present a case of cervicothoracic OPLL suggesting that electrophysiologic monitoring can be used to document the occurrence of paralysis with resection of spinous processes. CASE REPORTA 73-year-old man presented with cervicothoracic OPLL, a Japanese Orthopaedic Association (JOA) score for cervical myelopathy of 7.5 (17 points is full points) and JOA score for thoracic myelopathy of 5.5 (11 points is full points). The patient complained of bilateral numbness, clumsiness of his hands, bilateral motor weakness of his lower extremities (manual muscle testing: MMT at grade 4 out of 5), hypoesthesia in both lower limbs (Grade 1-5 out of 10) and inability to walk without a handrail. Reconstructed images from a computerized tomography (CT) myelogram showed extensive segmental OPLL, in particular at C4-5 (Figure 1a), T2-3 and T7-8 levels (Figure 1b). Thoracic MRI showed severe compression of the spinal cord at T2-3 and T7-8 (Figure 1c). The kyphotic Cobb's angle between the upper endplate of the C7 an...

Efficacy of posterior decompression and fixation based on ossification-kyphosis angle criteria for multilevel ossification of the posterior longitudinal ligament in the thoracic spine

“…16 A posture change from supine to a prone position during surgery decreases spinal cord evoked potentials, which may also be decreased by resection of the spinous process alone in some cases. 13 Aggravation of paralysis just by sitting after surgery has also been reported. 9 Therefore, surgery for T-OPLL should be carefully performed to prevent perioperative complications.…”