髋臼翻修过程中固定螺钉安全区的解剖学研究

The anatomical study of safe zones of the screw fixations in acetabular revision surgery

目的探讨评估髋臼翻修过程中假体固定螺钉的安全区域，测试四象限系统的有效性。方法2006年12月至2008年1月，制备11例（22髋）正常国人冷冻骨盆髋标本，剔除肌肉组织后每例标本固定在仰卧位置，安装假体前后拍摄X线片，测量髋臼旋转中心的位置变化。右侧半髋用于评估超大（Jumbo）髋臼假体和高中心髋臼假体固定螺钉的安全区。左侧半髋用于评估3种重建加强环固定螺钉的安全区（臼内区和臼外区）。结果超大髋臼假体前上象限和前下象限发生了神经或血管损伤。高中心髋臼时除了后上象限后半部和后下象限以外其余象限均发生了神经或血管损伤。Müller重建环在前上象限（臼内区和臼外区）发生了神经或血管损伤。Ganz重建环在前上象限（臼内区和臼外区）和臼顶区发生了神经或血管损伤，Burch—Schneider重建网笼在前上象限（臼内区和臼外区）和坐骨固定钉（当出骨长度大于15mm时）发生了神经或血管损伤。结论应用Jumbo非骨水泥假体和重建环时可以参照初次全髋关节置换时叙述的安全区。高中心髋臼手术时，我们常用的四象限方法需要改进，前上象限及后上象限前部和臼顶区为不安全区域。

Objective To evaluate the safe zones of screw fixations of Jumbo cup and reinforcement rings in acetabular revision surgery. Methods From December 2006 to January 2008, 11 fresh frozen human cadaver pelvises were prepared by removing all soft tissues except the medial neurovascular structures, each specimen was held in supine position with clamps. The anteroposterior radiographs were taken after the Jumbo cups or reinforcement rings were fixed in places. Left sides of acetabulum were used to create the models to evaluate the safe zones of the high hip center and Jumbo cups. Right sides were used to evaluate the safe zones of 3 different designs of acetabular reinforcement rings （Mtiller, Ganz, Burch- Schneider cage）. Results Jumbo cups： screws in the superoanterior and anteroinferior quadrants could cause neurovascular injuries. High hip center： neurovascular injuries could be expected in all quadrants except the inferoposterior and posterior half of superoposterior quadrant. Mtiller ring： screws placed in the intra-acetabular and extra-acetabular areas of the superoanterior quadrant could cause neurovascular injuries. Ganz ring：the screws placed in superoanterior quadrant and apex area were dangerous. The insults were confirmed in all of the specimens. Burch-Schneider cage ： the medial nervous and vaseulature structures were injured in all of the specimens if the screws placed in the superoanterior （intra-acetabular and extra- acetabular） quadrant. Screws for ischial fixation could cause sciatic nerve injury. Conclusions In revision acetabular surgery, the superoanterior quadrant, the anterior half of the superoposterior quadrant and the implant＇s central area are unsafe for screw fixation, especially when the exposed thread is longer than 15 mm.