The Study Of The Atlantooccipital Malformation Complex Basic And Clinical

The first partObjective To study the anatomical relationship between C1-2and Vertebralartery.Methods Ten adult cadaveric specimens of antiseptic fixed were studied.the veins and arteries were injected with coloured silicon. We followed thenomenclature clarified by Cacciola. The artery during its course from thetransverse process of C3to the transverse process of axis was named after V1segment, the artery during its course from the axis transverse process to the atlastransverse process was named after V2segment and the segment of the artery afterits exit from the transverse foramen of atlas to the point of its dural entry wasnamed after V3segment. The relationship of the artery to the atlanto-axial Jointand facets, distance of the location of the artery from the midline, from the C2ganglion and from the other surgery related landmarks were researched. The extentof occupancy of the artery into the vertebral artery groove on the inferior surfaceof the superior facet of the axis, and over the posterior arch of the atlas wasstudied.Results The V1segment of the vertebral artery takes a varying degree ofloop inside the vertebral artery foramen on the inferior aspect of the superior facetof the axis. The loop ex-tends towards the midline and was at an average distanceof14.6mm from the midline of the vertebral body. The V2segment of the arterytakes an initial lateral loop after its exit from the transverse process of the axis. The average distance of the artery from the lateral end of the C2ganglion was7.7mm and from the dural tube was15.6mm. The vertebral artery groove in thesuperior facet of axis and the groove over the posterior arch of the atlas werecompletely occupied by the vertebral artery only in six sides and in nonerespectively, suggesting the possibility of the dynamic nature of the relationship ofthe artery to the bone.Conclusions The vertebral artery adopts a serpentine course in relationshipto the axis, making it susceptible to injury during the surgical procedures in theregion. The foundation of reducing the possibility of vertebral artery injury is veryfamiliar with its anatomy characteristic. The second partObjective To investigate clinical experience in the treatment of atlantoaxialdislocation through screw and rod (plate) internal fixation technique with cervicalposterior approach.Methods From January2010to November2013,11patients who werediagnosed as atlantoaxial dislocation and treated through screw-titanium rods(plate) internal fixation technique with cervical posterior approach inNeurosurgery Department of Ningxia Medical University Affiliated Hospital wereincluded in this trial.There were3male and8female aged from9to50yearold(mean age was36.8year old).6cases had basilar impression,2cases hadAtlanto occipital fusion,3cases had platybasia and7cases had Chiarimalformation. All patients were processed CT3D reconstruction of cranio cervicaljunction,and modified anterior atlantoodontoid interval were measured from imageof bone window in sagittal view. If MADI was more than3mm,the patient couldbe diagnosed as atlantoaxial dislocation.In this trial, mean MADI was5.04±1.74mm.All patients were treated with surgery under the condition of generalanesthesia,prone position and fixed head.In operation, after separating theoccipital muscle,pillow scales, the margin of the foramen magnum spinous andlamina were revealed. After separating the two sides,atlantoaxial pedicle isthmusand atlantoaxial facet were revealed. Then atlas lateral screws, pedicle screw wereplaced,atlantoaxial dislocation were reset,titanium rod (plate) between screwswere fixed.Cartilages at atlantoaxial joint were cleared and autologous cancellousbone were packed in the joint cavity and surrounding facet. Foramen magnumdecompression were made simultaneously in patients with Arnold-Chiarimalformation,and the size of bone window was3cm×3cm. Postoperative follow-upcontained the review of cervical spine CT and MRI. Before operation, Post-operative JOA score and imaging were used to assess improvement degreeand therapeutic effect?Results All patients were followed up from3to5months, an average of3.5months.11patients sat up and got down and began rehabilitation in1week aftersurgery with general neck circumstance.Clinical symptoms of9cases after surgerywere significantly improved except2case had no significant changes,and none ofthem had occurred injury of spinal, nerve root or vertebral artery.Two weeks aftersurgery, CT scan of three-dimensional reconstruction showed that except titaniumrods of one case appeared to return to the outside, the location of screw inremaining patients were good,no pull or shift and postoperative fixation ofpreoperative vertebral displacement were good.Although the follow-up time wasdifferent, but implanted bone have growth and integration in different levels.Conclusion The technique of screw-titanium rods (plate) internal fixationwith cervical posterior approach in the treatment of atlantoaxial dislocation is safe,effective and reliable.After surgery,oppression of the ventral and dorsal spinal islifted,the stability of the spine between occipital and cervical region is good.Thedisease is significantly prevented to develop further and the clinical symptoms areimproved better.