Clinical And Three-Dimensional Finite Element Study On The Concurrent Abnormal Curvature Of Under Cervical Spine After Occipital Cervical Fusion

BackgroundFor treatment of occipital cervical(OC-C2) fusion in patients with craniocervical region malformation, with the development of Science & Technology in the cervical spine surgery and posterior occipital cervical fusion in the improvement of craniocervical junction malformation patients clinical symptoms, improving the occipital cervical stability and fusion rate have great progress. Although each operation method is to reach the operation expected results and ensure patient satisfaction as the goal. However, some postoperative and disease is greatly reduces the quality of life of patients, such as many patients appear under the curvature of cervical spine straight, kyphosis, swan neck deformity and cervical curvature abnormality alteration, some patients also appeared the corresponding clinical symptoms, serious or even required surgical treatment, in recent years the occipital cervical fusion after cervical curvature abnormality become scholars are concerned about the topic.Objective1, through collecting and analyzing the clinical data, determine the area underwent occipitocervical fusion malformation of craniocervical junction when the right occipital cervical angle, clear occipital cervical angle on postoperative effect(JOA score) effect.2, through the establishment of different occipital cervical fusion angle with skull base of the whole cervical spine three-dimensional finite element model,through on cervical segmental activity and tension of anterior longitudinal ligament,intervertebral disc should force, facet joint capsule should force data of the comparative analysis, to explore the ideal occipitocervical fusion angle.3, through the establishment of occipital cervical fusion and lamina of c2c3 spontaneous fusion with skull base cervical three-dimensional finite element model of c2c3 lamina fusion effect of lower cervical spine biomechanics and for the c2c3 lamina fusion resulted in lower cervical curvature abnormality provides theoretical basis.Method1, acquisition and analysis in January 2011- January 2013 period in the First Affiliated Hospital of Zhengzhou University with occipital cervical fusion in the treatment of 41 patients in the perspective of the integration and operation under cervical(C2-C7) COBB angle changes in the and the Japanese Orthopaedic Association(JOA) scores were, the appropriate fusion angle analysis.CT data of 2, the application of healthy volunteers to construct skull base to the seventh cervical with skull base cervical three-dimensional finite element model, and model in flexion, extension, lateral flexion and rotation conditions the festival activities and reference test data are compared, and the effectiveness model validation.3, in the skull base with cervical three-dimensional finite element based on according to the operation load of occipital cervical fusion internal fixation system(OC-C2), and through changing the angle of the neck pillow and construct neck pillow are different fusion angle with skull base of the whole cervical spine three-dimensional finite element model(pillow neck angle of 5 degrees, normal occipital cervical angle(15 degrees), occipital cervical angle at a temperature of 25DEG) of three kinds of cervical occipital cervical fusion angle model under the cervical segments and stress were analyzed and compared.4, in normal angle of occipital cervical fusion with skull base cervical three-dimensional finite element model, through the c2c3 interlaminar interspinousligament, supraspinous ligament and ligamentum flavum changes to cortical bone material simulation c2c3 laminectomy and fusion. Comparison of occipital cervical fusion after posterior fusion C2C3 model with occipital cervical fusion C2C3 after laminectomy without fusion model of lower cervical segmental motion and stress analysis.Result1, the fusion angle is 9 degrees-22 degrees, cervical spinal deformity occurred in the least likely after operation, the neurological function score(JOA score) are least likely to decrease rapidly.2, with skull base of the whole cervical spine three-dimensional finite element model of a total of 716764 unit, 263855 nodes and vivid shape, with literature data for comparison and validation, prove this experiment used cervical three-dimensional finite element model can be used for biomechanical research.3, occipital cervical fusion angle O-C2 angles 5 degrees and cervico occipital angle at a temperature of 25 DEG model in flexion, extension, lateral flexion and rotation conditions, degree of lower cervical spine most segments, the anterior longitudinal ligament tension, facet joint capsule stress greater than normal angle model; occipital cervical fusion angle O-C2 angles 5 degrees and cervico occipital angle at a temperature of 25 DEG model in the stretched condition, most of the segment of cervical intervertebral disc stress was greater than that of the normal angle model, in flexion, lateral bending and rotation conditions, each model. There were no significant differences among4, the c2c3 lamina fusion model to compare the c2c3 laminar non fusion model,overall in flexion, extension, lateral flexion and rotation conditions nowadays cervical sections section activity and tension of anterior longitudinal ligament, intervertebral disc should force, facet joint capsule stress in the c2c3 segments obviously greatly reduced, but in c3c4, c4c5, CSC6, degree of cervical segments C6C7 segments model,should force difference is not obvious.Conclusion1, posterior occipital cervical fusion, occipital cervical angle can be selected 9DEG-22 deg.2, occipital cervical fusion angle of 25 degrees can seriously affect the posterior occipital cervical fusion of cervical segmental activity and tension of anterior longitudinal ligament, intervertebral disc should force, facet joint capsule stress,could eventually lead to the degeneration of cervical segments, cause abnormal cervical curvature; according to the experimental research, such as no special circumstances such as occipito cervical deformity or anatomical abnormalities we propose occipitocervical fusion angle is fixed in the normal angle 9 degrees in the range of- 22 degrees.3, C2C3 after cervical posterior fusion in segment C2C3 activity was limited.But in the c3c4, C4 CS, CSC6, fusion C6C7 segment c2c3 lamina under the cervical segments, tension of anterior longitudinal ligament, intervertebral disc should force,facet joint capsule stress did not change significantly, which shows in these segments c2c3 lamina spontaneous fusion effect for the lower cervical spine biomechanics as occipitocervical fusion angle the factors. On the other hand also shows c2c3 lamina by spontaneous fusion caused by the lower nodes segment degeneration could be is a chronic course of disease.