《lcp内固定原则》ppt课件.pptVIP

如何选用不同的螺钉 尤其对于结合使用螺钉的情况 自钻 LHS 自攻 LHS 传统螺钉 传统的 自钻 LHS 自攻 LHS 孔 DCUs 锁定孔 锁定孔 单皮质 NO YES YES/NO l双皮质 YES NO/YES YES/NO 功能 加压 锁定 锁定 不同螺钉的置入顺序 螺钉和骨锚合力的重要性… 要将接骨板和螺钉置于骨中央! 锁定钢板与螺钉 手术技术: 必须先复位 股骨牵张器 外固定支架 牵引床 先使用拉力螺钉协助复位，再使用锁定螺钉稳定骨折 手术技术 普通钢板 锁定钢板 钢板能协助骨折复位 钢板要求解剖塑形 锁定螺钉不能帮助骨折复位 钢板无需塑形 螺钉必须双侧皮质骨固定 锁定螺钉可以单侧皮质固定 LISS钢板 锁定钢板 LCP干钢板 LCP 髁钢板 LCP 胫骨近端钢板 LCP 小钢板 LCP 肱骨远端钢板 Inverse relationship of stability or “rigidity” of fixation and the vascularity or “biologics’” of fracture consideration. Minimum Stability Requires Maximum Vascularity and Vice Versa (Animation) Summarize 5 Again we see the initial stress in the bone due to tightening. When the bone is loaded along its axis, the bone around the screw is compressed on the load side of the fracture. As the load is increased, and the angle between the screw and the plate starts to change, the resultant loading vector on the screw changes from pure compression to a compressive and a tensile component. It is this additional tensile component which, when the elastic limit of the bone is exceeded, will cause toggling and eventual collapse across the fracture gap. The lock plate does not exhibit this behavior as the angles of the screws are fixed and there is no pre-load **Click on image for video clip** Demonstration of fixed angled screws placed in multiple planes in poor bone. 1st Fixation. Traditional treatment for a proximal humerus fracture would be the cloverleaf plate. 2nd Fixation With 3.5mm locked screws in multiple angles. Note the main difference. Bone captured between fixed angled screws verses the effect of the screw thread. (Animation) Summarize (Animation: Points brought in individually) (Animation: Points brought in individually) 4.5mm Cortex screw has a 3.2mm core diameter 4.0mm Locking screw has a 3.4mm core diameter 5.0mm Locking screw has a 4.4mm core diameter 3.5mm Cortex screw has a 2.5mm core diameter 3.5mm Locking screw has a 2.9mm core diameter (Animation) Summarize Here are th