Posterior Approach Decompression And Stabilization By Internal Fixation Treat Serious Cervical Ossification Of The Posterior Longitudinal Ligament

1.Objectives:To elucidate efficacy and results of posterior approach decompression(expansive open-door laminoplasty and laminectomy) and stabilization by internal fixation in serious cervical ossification of the posterior longitudinal ligament.2.Macterials and Methods:According to inclusion and exclusion criteria,we reviewed data in 18 patients who underwent either cervical expansive open-door laminoplasty or laminectomy and stabilization by internal fixation from department of orthopedics of the first clinical medical college of Fujian Medical University between 2003 and 2008.The inclusion criteria:(1).JOA(Japanese Orthopedic Association) scores(Table 2)≤8;(2).the effective anterior-posterior canal diameter≤6mm;(3). The patients have whole clinical data and follow-up information.The exclusion criteria was spinal cord injury as trauma.All 18 patients with COPLL adopted internal fixation systems with multi-axial screws and titanium rod,including 11 cases with expansive open-door laminoplasty and 7 cases with laminectomy.Cervical 3 to 6 lateral mass screws fixed with Magel's method,and cervical 2 and 7 lateral mass screws fixed with pedicle screws insertion's method.We adopt retrospective case analysis,telephone and/or out-patient follow-up study.Main outcome measures: clinical data,preoperative and postoperative JOA score,the improving rate of JOA,et al.Imaging data[X-ray,CT scan + three-dimensional reconstruction,MRI(magnetic resonance imaging)(1.5T)]:preoperative and postoperative anterior-posterior canal diameter,OPLL%,cervical curvature index,spinal cord changes,and open-door angle etc.3.Results:(1 ),The mean follow-up period of 18 patients was 26.56months(range 3～39 months).(2),clinical symptoms:The mean JOA score of 18 patients significantly increased from 6.11+1.88 points before operation to 12.61±2.40 points at the latest follow-up(P＜0.01),postoperative clinical symptoms have obvious alleviation.The mean improving rate of JOA was 61.01%(range 18.18%-88.89%).The results of the improving rate of JOA were 4 cases of excellent persons (≥75%),accounting for 22.22%,11 cases of good persons(50%-74%),accounting for 61.11%,2 cases of fair persons(25%-49%),accounting for 11.11%,1 cases of poor persons(<25%),accounting for 5.56%.(3),Image Results:All of the 18 patients were reviewed X-ray and CT scan,which 10 cases were reviewed three-dimensional reconstruction,which were showed good cervical curvature,the expansion of spinal canal full,screw-rod fixation system in place.17 cases were reviewed MRI(1.5T), which were showed spinal cord back to leave the front of migrating osteophyte or OPLL-induced pressure,such as objects,epidural expansion of good,thorough decompression.11 cases with expansive open-door laminoplasty were showed that the average open angle was 52.73~0±5.53~0,the average effective spinal canal sagittal diameter significantly increased from 4.18±1.07mm before operation to 9.57±0.8mm(P＜0.01),and the average occupying ratio of OPLL significantly decreased from 65.19%before operation to 42.52%(P＜0.01).There were no statistical significance of the preoperative and postoperative relevant factors between laminoplasty and laminectomy.(4),complications:2 patients with laminoplasty appeared segmental root palsy of C5,which one recovered by 6 months,and another recovered by 18 months.1 patient appeared incomplete paralyses of spinal cord,which recovered gradually by vigorous conservative treatment;1 patient died result from respiratory infections and respiratory failure after 4 months.All of the 18 patients were not kyphosis,restenosis,axial symptoms(AS),broken nails,broken rods,loose, or screw migration into the vertebral artery hole,intervertebral foramen,spinal canal, etc.4.Conclusions:(1).Cord decompression with expansive open-door laminoplasty and laminectomy using internal fixation may improve the neurological outcome even in patients presenting late,and improvement may have major'uality of life'benefits for these patients.Open angle of 45~0-60~0 can be fully decompression. (2).We have already initiated some modifications in the surgical procedure to confront some problems,which have been successful to a certain degree,suggested by the preliminary results of our clinical studies.However,there still remain a number of unsolved problems,including segmental root paralysis,incomplete paralyses of spinal cord.Although segmental root paralysis was the most frequent and notorious complication after posterior approach decompression and stabilization by internal fixation,it did not affect markedly the recovery of postoperative neural function, moreover,the majority of SRP would complete recovery within 2 years after surgery by conservative treatment.(3).Ihe standard of JOA scores combined with the effective anterior-posterior canal diameter will be exacter to reflect the severity of the disease.