Novak P J, Wexler G M, Williams J S, Bach B R, Bush-Joseph C A
Department of Orthopaedic Surgery, Rush Medical College, Rush-Presbyterian-St. Luke's Medical Center, Chicago, IL 60612, USA.
Arthroscopy. 1996 Aug;12(4):470-3. doi: 10.1016/s0749-8063(96)90042-0.
Endoscopic (single-incision) anterior cruciate ligament (ACL) reconstruction with bone patellar tendon bone can usually be secured with interference screws on the femur and tibia. Infrequently, patella alta, which results in a longer tendinous component of the graft construct, can result in construct mismatch, resulting in a large portion of the tibial bone plug extruding from the tibial tunnel, requiring graft fixation with staples or a suture/screw and post technique. This study investigated the hypothesis that initial graft fixation could be enhanced if the bone plug was removed and press fit into the tibial tunnel and then secured with an interference screw in the scenario of graft construct mismatch. Initial biomechanical fixation strengths of bovine patellar tendon were compared using a screw and post suture fixation compared with a free bone plug, which was removed from the graft and sandwiched along with the soft tissue with an interference screw. Twenty-eight bovine knees were randomly divided into two groups. Graft fixation was performed with a free bone plug excised from the tibial tubercle portion of the bone tendon bone construct. Fixation was achieved with a cannulated 9-mm x 20-mm interference screw. Fixation was performed in group 2 patients with a Krackow suture of no. 5 Ticron secured over a screw and post. An Instron materials testing system was used and loading rates at 1 mm/sec until failure was performed. Statistically significant differences were noted for load to failure and stiffness (P < .001). Group 1 specimens' mean maximum load to failure was 669 N (range, 511 to 819 N), whereas the load to failure for group 2 patients was 374 N (range, 266 to 491 N). Group 1 stiffness was 90 N/mm (range, 50 to 122 N/m) compared with a mean stiffness of 24 N/m (range, 16 to 33 N/m) for group 2 knees. In our bovine model, free bone block interference fixation was stronger and stiffer than fixation using sutures tied over a post. This fixation method of securing a soft tissue graft with an interference screw warrants further clinical investigation and may offer an improvement to the alternative of suture/post fixation.
采用骨-髌腱-骨的关节镜下（单切口）前交叉韧带（ACL）重建术，通常可通过股骨和胫骨上的挤压螺钉进行固定。偶尔会出现高位髌骨，这会导致移植物结构中腱性部分变长，进而导致结构不匹配，致使胫骨骨块的一大部分从胫骨隧道中挤出，此时需要用吻合钉或缝线/螺钉固定移植物及后续技术。本研究探讨了如下假设：在移植物结构不匹配的情况下，如果去除骨块并压入胫骨隧道，然后用挤压螺钉固定，能否增强初始移植物固定效果。将牛髌腱的初始生物力学固定强度，采用螺钉和缝线后置固定法与游离骨块进行比较，游离骨块从移植物上取下，与软组织一起用挤压螺钉夹在中间。28个牛膝关节随机分为两组。移植物固定采用从骨-腱-骨结构的胫骨结节部分切下的游离骨块。使用9毫米×20毫米的空心挤压螺钉实现固定。第2组患者采用5号Ticron的Krackow缝线固定在螺钉和后置物上进行固定。使用Instron材料测试系统，以1毫米/秒的加载速率直至失效。在失效载荷和刚度方面观察到统计学上的显著差异（P <.001）。第1组标本的平均最大失效载荷为669牛（范围为511至819牛），而第2组患者的失效载荷为374牛（范围为266至491牛）。第1组的刚度为90牛/毫米（范围为50至122牛/米），而第2组膝关节的平均刚度为24牛/米（范围为16至33牛/米）。在我们的牛模型中，游离骨块挤压固定比使用后置物上打结的缝线固定更强且更硬。这种用挤压螺钉固定软组织移植物的固定方法值得进一步临床研究，可能会改进缝线/后置固定的替代方法。
