AF三维椎弓根螺钉系统的研制及其临床应用

Biomechanics of AF new 3-d pedical screw system andtreatment of 31 patients with unstable thoracolumbarfracture

作者在ＲＦ系统的基础上，进一步研制成功了ＡＦ（ａｔｌａｓｆｉｘａｔｉｏｎ）系统。本系统将ＡＯ系统可在三维空间调整的万向关节结构，改为虽无万向关节却可在三维空间可调的系统，既保留了ＲＦ系统角度螺钉重建脊柱生理弯曲的准确性与坚固性，又无角度螺钉Ｕ型口与螺杆结合使三维调整所受的限制，更无万向关节易松动的缺陷，因此同时具备了ＡＯ及ＲＦ两个系统的优点。其特点为：结构简单，调节方便，手术操作大为简化。临床应用３１例，压缩骨折１例，爆裂骨折２２例，Ｃｈａｎｃｅ骨折６例，骨折脱位２例，均达解剖复位及牢固固定。术前骨折块椎管占位＞３０％者１７例，术后椎管面积平均增力０３３％。平均随访８．５个月，除ＦｒａｎｋｌｅＡ级２例无改善外，Ｂ级以下１９例均至少提高一个等级，Ｃ级以下１４例，１１例脊髓功能完全恢复。

AbstractFor anatomic reduction of the spinal frectures,the3 dimenxional multiple correction forces were needed. Several Dedical screw svstems were designed for redu-cion and fixation of the spinal fractures as the AO uni-versal joint syxtem and the RF angle screw system.Because of the contradiction of the universal joint andthe fixed angle, a new generation of RF was designedand named AF(atlas fixator)svstem. Thsis a newconcept of 3-D reduction, without complex structure asuniversal joint, but has truly 3-D adjustment that al-lowed to reduce the intra-Canal compromise. It alsoprovided rigid fixation to maintain the reduction. Com-parison with CD,AO, Steffee, and RF,the AF wastrulv 3-D reduction in XTZ axis. It provided strongsvmmetric transmitter orthotic force to correct the de-formity. 31 patients with unstable thoracolumbar frac-tures were treated with the new AF svstem. 17 hadpartial(15)or complete(2)neurologic deficits. TheAF system provided accurate angle to restore the nor-mal thoracic-lumbar lordosis and to maintain it. Allpatients had a anatomic reduction by AF system,Thespinal canal area increased over 33%by CT scan (P<0. 01 ). All cases were followed up over 8 months. Noone deteriorated neurologically after AF fixation.