Analysis Of Micro-neurosurgical Treatment For Cervical Spondylotic Myelopathy

Objective:This study was designed to analyze the anatomy and image of cervical vertebral column,nerves and associated structure to provide the pathological basis and comprehensive knowledge of cervical spondylosis.On the foundation of the anatomical measurement of different approach of invasive microsurgery(MIMS), combined with advanced MIMS techniques and related image,imageological diagnosis of cervical spondylosis was improved to facilitate the localization of responsible focus,to advance MIMS safety,and to decrease related complication.The operative effect of myelopathy was observed,and,with the analysis of follow-up results and retrospective clinical data,the surgical treatment effect of myelopathy and coupled factors also studied.Materials and Methods:This study consisted of three parts:basic study,clinical imaging investigation,and case analysis.Basic study was aimed to measure the anatomy of different MIMS approach encountered in the surgical operation.15 Chinese adult cervical spines were analyzed through MIMS,and the evaluative indexes were as follows:1) the different composition of each cervical cord and nerve root,and the incidence rate of cervical root malposition;2) the morphology,trajectory, and adjacent structure of each cervical intervertebral foramen and nerve root canal;3) micro-anatomy of posterior roots of cervical nerves.Clinical investigation was intended to use general imaging,especially Magnetic Resonance Imaging(MRI),united with the anatomical data in basic study to observe cervical spondylosis.The evaluative indicators were 1) nerve-root-trajectory-angle dependent MRI,which was performed corresponding with the micro-anatomy of cervical nerve root to present the thorough comprehension of cervical roots commonly involved in cervical spondylosis;2) a novel imaging of cervical spondylosis was compared with conventional coronary,sagittal,axial MRI which was carried out to examine the severity and effect of cervical spondylosis,and to guide clinical practice. In case analysis 35 patients with cervical spondylosis,administrated in Tianjin Medical University General Hospital from Jan.2002 to Mar.2008,were followed up and their clinical data analyzed.JOA,a functional evaluation scale of cervical spine, was performed pre-operation,post-operation,and follow-up.Upper extremity movement score,lower extremity movement score,sensory function score,bladder function score,total score,and improvement rate were analyzed by SPSS 13.0.The JOA score of pre-injury,post-injury,and follow-up were compared by One-way ANOVA,and p＜0.05 set as significance.Result:The morphology and measurement of intervertebral foramen and nerve roots: intervertebral foramen is funnel-shaped,and its' medial and lateral entrance are the margins of pedicle of vertebral arch which are the least narrow.The intervertebral foramen presents ellipse-like or oval-like,and anteroposterior diameter is shorter than rostral-caudal one.The vertebral foramens(canals) in inferior cervical spine were longer than those in superior.Rostral-caudal and anteroposterior diameters of C4,5,6 intervertebral foramen are the shortest,and C3,7 the longest.The rootlets of C6-7 posterior roots differ significantly,and C5-6 and C6-7 anastomosed branch were notable.The nerve-root-trajectory-angle dependent MRI:the special functional position with conventional axial,sagittal,coronary MRI and three-dimensional high-resolution MRI fully illustrate the C3-7 nerve roots and trajectories.Retrospective analysis:imaging data and clinical records of 35 patients are analyzed.The mean of pre-injury JOA score is 11.71,post-injury 14.71,and the average improve rate is 63.14%.Conclusion:The characteristic of cervical spine anatomy correlates with clinical manifestations.Cervical spondylosis involves multiple segments commonly,but the responsible focus are 1-2 segments.The comprehension of Chinese cervical anatomy is essential for the surgical treatments.The accurate localization of responsible focus from pre-operative imaging is indispensable for the MIMS on cervical spondylosis.Conventional coronary,sagittal, and axial MRI have some drawbacks.The angle-adjusted MRI is consistent with the anatomy of cervical nerve roots,and could improve the accuracy of localization.JOA scale is concise and practical.Although it may be influenced by patients, the comparison between pre and post operation score is an objective index to evaluate the effect of surgical treatment.The effect of MIMS on cervical spondylosis is better than that of conventional anterior and posterior depression in such way that bleeding in operation is few, vertebral column stabilized,and post-operational clinical manifestation improve quickly with less complication.