The Anatomy Of The Cervical And The Biomechanical And Clinical Research Of The Intra-articular Pressure Changes Of The Superior Intervertebral Cervical Facet After Bryan Cervical Artificial Disc Replacement

Cervical spondylosis are severe cervical degenerative diseases ,the basic concept are the cervical disc degenerative change and the clinical symptom and objective sign produce by Secondary and degenerative change of intervertebral articulation which stimulate or compress nerve root,spinal cord,blood vessel and related tissue. Cervical spondylosis are common medical conditions treated by spine surgeons,including cervical spondylotic radiculopathy, cervical spondylotic myelopathy, cervical spondylotic vertebrarterial impairment , cervical spondylotic sympathetic imbalance , cervical spondylotic combination.. There are many conservative ways to treat the cervical degenerative diseases ,such as neck collar protection, traction treatment, physical treatment, non -steroidal anti-inflammatory drugs NSAIDs. Not all the diseases can be treated the conservative treatments, operation is the last choice of the cervical degenerative diseases. Such as: anterior percutaneous discectomy, disc dissect with lasic,the disc decompression/excision and discectomy with interbody fusion, microendoscopic discectomy, automated percutaneous cervical discectomy, prosthetic cervical nucleus , artificial disc replacement,et al. The reports of the effect on the adjacent disc is few.With the development of the cervical artificial disc and successful clinical use of the artifical disc,the number of the patient who accept the artificial disc increased quickily,but can all the artificial disc fulfill the function of the disc,and the side effect on the adjacent disc,especially the inferior intervertebral cervical facet joint is unreported.First, to observe and measure the cervical pedicle of vertebral arch during the anatomical and image reconstructional test in this study. Computerized Tomogram (CT) was used for scanning. Multiply plane reconstruction(MPR) was executed. The width and the height of spongy bone were measured. The cyclo-shaped migration sensor was used to measure the intra-articular pressure change of the inferior intervertebral cervical during the biomechanical test in this study. In order to reveal the correlation between the discectomy,the intervertebral fusion and the artificial disc replacement superior adjacent intervertebral cervical facet joint,the change of the stress of intervertebral cervical facet between C_4/5 which applied with load of neutrality and pure moment of axial,flexion,extension, ipsilateral and Contralateral bending in C_5/6. Furthermore the clinical cases of the artificial disc replacement and the intervertebral fusion were followed in different time. The clinical result of the different treatment were evaluated, and the relationship of the different treatment and the superior intervertebral cervical facet joint were also evaluated. Chapter I : The experimental observation of the the anatomical structure of the cervical pedicle of vertebral archObjective To observe and measure the cervical pedicle of vertebral arch and multiply plane reconstruction after the spinal CT scanning. The width and the height of spongy bone were measured and the statistical analyses were made. In order to guide the screw fixation of cervical vertebrae.Method Twenty human spines were gathered(10 fresh-frozen cervical spine segments and 10 preservative cadavers). To observe and measure the cervical spine segments and multiply plane reconstruction after the spinal CT scanning in different segments. First, In the transverse section of the pedicle isthmus, the height (PH) and the width (PW) of the pedicle, superior cortical thickness (SCT), inferior cortical thickness (ICT), medial cortical thickness (MCT),lateral cortical thickness (LCT), the width (SBW) and the height (SBH) of spongy bone were measured. Then, to dissect these segments, Direct measurements including the distance of the pedicle from the superior and inferior nerve roots and the dura were performed.Result The medial cortical thickness was significantly thicker than lateral cortical thickness in different segments.(P<0.05), the parameters of the pedicle in the superior and inferior side were not significantly different. The width (SBW) of spongy bone have same varying tendency with the height (SBH) of spongy bone,the thickest is C₇.The spongy bone is a tear shaped. There was no distance being found between the pedicle and the superior nerve root, nor between the pedicle and the dural sac at C_3-7 in all specimens. The measured distances between the pedicle and the inferior nerve roots in all specimens were ranging from 1. 4 mm to 1. 6 mm. The farthest distance is 1.6mm in C₆.Conclusion 1.The spinal CT can illustrate the internal structures of the pedicle well. 2. The thinner lateral cortical shell easy to rupture during the screw fixation than the medial. 3. The incidence of neurologic injuries may be higher in screw penetration of the medial or superior cortex of the pedicle than in screw penetration of the inferior cortex of the pedicle.Chapter II: The biomechanical research of the the intra -articular pressure changes of the superior intervertebral cervical facet joint after artificial disc replacementObjective To compare the stress changes of C_4/5 intervertebral cervical facet joint pre-and post C_5/6 discetomy,artificial disc replacement ,and the intervertebral fusion the during the different motion condition,and to observe the biomechanical effect on the superior intervertebral cervical facet joint after different treatment policy. Method Eleven healthy adult fresh-frozen cervical spine segments were utilized in this investigation and biomechanically evaluated under the following C_5/6 conditions: intact spine,discectomy,the Bryan Disc prosthesis implantation,the interbody fusion.The testing was performed under loading of 25N,50N,75N,100N,125N,150N of neutrality and pure moments of axial,flexion,extension, ipsilateral and Contralateral bending on each group. The intra-articular pressure changes of the superior intervertebral cervical facet joint were mearsure and the statistical analyses were made. by SPSS for windows 11.0,the statistic significance was set at a=0.05.Result Under axial,flexion,extension, ipsilateral and Contralateral bending loading, the intra-articular pressure changes of the superior intervertebral cervical facet joint of the interbody fusion increase obviously , comparing with the intact spine and discectomy. There are significantly different (P<0.05). The stress in the Bryan Disc prosthesis implantation were not significantly different comparing with the intact spine and discectomy(P>0.05). The stress in discectomy were not significantly different comparing with the intact spine(P>0.05).Conclusion 1. The intact spine have perfect biomechanical character.2.The discectomy has the proximate biomechanical character.3. The interbody fusion can increase the stress of inferior intervertebral cervical facet joint and may be accelerate degenerative change. 4. The Bryan Disc prosthesis implantation can recover the proximate normal stress of intervertebral cervical facet joint, to achieve normal biomechanical character.Chapter III: The clinical research of the Bryan Disc prosthesis implantationObjective To compare the effect of the superior intervertebral cervical facet joint through the clinical cases of the artificial disc replacement and the intervertebral fusion were followed in different time.Method Sixteen cases who underwent artifical cervical disc replacement from 1998 to 2006 were followed-up(group A). Thirty cases who underwent the interbody fusion were followed-up in the corresponding time period. Then to divide the interbody fusion cases into two group, short term followed-up goup(groupBl) and long term followed-up group(group B2). With the phone call, letters and outpatient service, The score of JOA, the score of Odom, the X-ray film pre-operation, 3, 6, 12, 24 months post-operation and C_4/5 range of motion(ROM) of X-ray were collected.. The score of JOA, the score of Odom and C_4/5 range of motion(ROM),were mearsure and the statistical analyses were made. by SPSS for windows 11.0,the statistic significance was set atα=0.05.Result 1. The artificial disc replacement and the interbody fusion groupB1 have good JOA and Odom score comparing with pre-operation, were significantly different (P<0.01).But were not significantly different in 3,6 months in JOA score(P>0.05). Their C_4/5 range of motion(ROM) were not significantly different comparing with pre -operation (P>0.05)and there were not significantly different in 3,6 months between the two groups(P>0.05).2. The short term followed-up goup(groupBl) and long term followed-up group(group B2) have good JOA and Odom score comparing with pre-operation, were significantly different (P<0.01). but in last followed-up ,group B1 have good JOA than group B2(P<0.01).These groups were not significantly different comparing with pre-operation in C4/5 range of motion(ROM) (P>0.05),but in long term ,there were significantly different bwteen two groups.Conclusion 1. The artificial disc replacement and the intervertebral fusion were have certain therapeutic effect in cervical spondylosis.2. The superior intervertebral cervical facet joint have rational stress distribution.3. The artificial disc replacement have good long term therapeutic effect than the intervertebral fusion.