En bloc open-door laminectomy and pedicle screw fixation for extremely severe cervical ossification of posterior longitudinal ligament

Abstract

Objective To evaluate the effect of en bloc open-door laminectomy and pedicle screw fixation for extremely severe cervical ossification of posterior longitudinal ligament (OPLL).Methods From January 2007 to December 2011,16 cases of serious cervical OPLL were treated,in which there were 13 males and 3 females,aged from 45 to 74 years (average,56.5 years).Spinal cord functional deterioration was related to minor activities of the neck,such as sneeze,cough or hyperextension of the neck,in 15 cases.One case suffered from aggravating neurological symptoms without a definite precipitating factor.The average preoperative Japanese Orthopaedic Score (JOA) was 7.1 ±1.8.Preoperative CT scans displayed the average stenotic rate (thickness of OPLL/sagittal diameter of the spinal canal) was 83.7％.All the patients received en bloc laminectomy and pedicle screw fixation of the cervical spine.Results All the patients were followed up for 3 months to 4 years (average,24.4±10 months).The JOA scores at 2 weeks,3 months,and the last follow-up postoperatively were 13.2±1.7,13.5 ±1.6 and 14.1 ±1.5,respectively; the improvement rates were 61.6％,64.6％ and 70.7％,respectively.The operative time ranged from 80 to 150 minutes (average,130 minutes),and blood loss ranged from 150 to 600 ml (range,300 ml).One case of postoperative wound hematoma,1 case of cerebrospinal fluid leakage and 3 cases of trapezius muscle pain occurred in this group.No serious complications,such as deep infection,deterioration of neurological dysfunction,vertebral artery injury and internal fixation failure,were noticed.Conclusion Owing to the minimum interference to the cervical spinal cord,stabilization of the decompressed segments and maintenance of cervical lordosis,en bloc open-door laminectomy and pedicle screw fixation is suitable for extremely severe cervical OPLL. Key words: Cervical vertebrae; Ossification of posterior longitudinal ligament; Bone screws