The Morphology Of The Cervical Intervertebral Foramen After The Unilateral Locked Facet Of Cervical Spine

The cervical unilateral facet dislocation is the destruction of the cervical three column structure after the flexion and rotation violence. It account 3%-11% of the incidence of cervical impair,and fewer than bilateral cervical fact dislocation.There is few nerves complication after cervical unilateral dislocation, same as the imaging appearance, so it is facility to miss diagnosised. As it is increasing these years, more and more people reconstruction it. Some researchers had used the method of biomechanics experiment to explain the change after unilateral facet dislocation, and fewer to study and research the morphology after dislocation.But the morphology of cervical intervertebral foramen is very important in clinical and the treatment. Objective: To study the pressure and morphology diversify of supra-paries,hypo-paries, ento-paries;and ecto-paries after unilateral Locked Facet of Cervical Spine, to plan use the .method of biomechanics to approach the diversify of Cervical intervertebral foramen. Methods: Four adult cervical spine specis,to fix C4-5 to be the only kinesic segment., meanwhile pasting the electrode slice on the supra-paries, hypo-paries,;ento-paries; and ecto-paries.After that we put one side of the specimen into clamping, the other side into wrench. Loading flection and rotation. Measuring the maximum force after unilateral locked facet of cervical spine,meanwhile to observe the condition of soft tissue. Results: We found that it is tensile force and tension upon ecto-paries and hypo-paries, also it is pressure and compression upon supra-paries and ento-paries during unilateral dislocation of the cervical spine. The force at the interlocking side of ecto-paries is largest,and then ento-paries.The force upon the the interlocking side of ecto-paries is extremely greater than opposite side. There is no conspicuous difference in other paris. The force that cause the unilateral facet dislocation is 70N The angle of rotation is 19.75°Supraspinous and interspinous ligaments are completely disrupt, Ipsilateral of dislocation facet's articular capsule is breakdown.,part of anterior longitudinal ligament and posterior longitudinal ligament are partly disrupt. Overtopping 50% of anulus fibrosus is breakdown. Conclusion: The ecto-paries and hypo-paries of interlocking and contralateral side suffered tensile force,meanwhile the hypo-paries and supra-paries suffered pressure during the cervical facet disloction. On the basis of mechanics principle the force in this position to make duty and energy maximum. Up on the same information of bilateral soft tissue, the trauma in this position is necessarily biggest.Through the observation upon the experiment specimen after the cervical facet disloction, we found that all specimen have the supraspinous and interspinous ligaments are completely disrupt, Ipsilateral of dislocation facet's articular capsule is breakdown.part of Overtopping 50% of anulus fibrosus is bredown. Thay are important in stabilization and before the dislocation these soft tissue must be brokendown. The interlocking side of ecto-paries which is in abnormal position cause to oppress, to produce clinical symptom. Reset the interlocking side of ecto-paries which is in abnormal position is the most significant the in the treatment. The essential conditon of soft tissue preparation before unilateral facet dislocation are supraspinous and interspinous ligaments are completely disrupt, Ipsilateral of dislocation facet's articular capsule is breakdown.part of Overtopping 50% of anulus fibrosus is breakdown.