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

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 <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. 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.

Circulating microRNAs as biomarkers for evaluating the severity of acute spinal cord injury.

STUDY DESIGN: An in vivo study in mouse models of spinal cord contusion. OBJECTIVES: To develop a novel indicator to anticipate the severity of spinal cord injury (SCI) during the acute phase and for the assessment of the efficacy of novel therapies. MicroRNAs (miRNAs) circulating in the peripheral blood are reported to modulate signaling between cells, and to be diagnostic markers for cancers. The purpose of this study was to identify circulating miRNAs for predicting the severity of SCI in the acute phase. SETTING: Department of Orthopaedic Surgery, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan. METHODS: Mouse SCI models were made using Infinite Horizon impactor with 50 or 70 kdyn compressing power following thoracic laminectomy. The mice were then divided into four groups: normal (without surgery), sham (laminectomy only), mild (50 kdyn), and severe (70 kdyn). TaqMan low-density array analysis and real-time PCR were performed to identify candidate miRNAs that were increased in the serum relative to the severity of SCI. RESULTS: The expression levels of miR-9*, miR-219 and miR-384-5p in the serum were significantly increased relative to the severity of SCI 12 h after injury. The expression of miR-9* was also significantly increased relative to injury severity at 3 and 24 h after injury. CONCLUSION: Serum miR-9*, miR-219 and miR-384-5p might be promising biomarkers for predicting the severity of SCI.