DeBerardino Thomas M, Lonergan Keith T, Brooks Daniel E
Keller Army Community Hospital, West Point, NY 10996, USA.
Am J Sports Med. 2008 Jan;36(1):142-8. doi: 10.1177/0363546507307393. Epub 2007 Sep 14.
Cadaveric testing has shown that double-bundle reconstruction better replicates the native anatomy of the posterior cruciate ligament. With the current trend toward allograft Achilles posterior cruciate ligament reconstructions, the need to determine a graft configuration with the highest tensile and pull-out strength has become paramount.
The split stacked Achilles allograft construct provides greater graft material to traverse the notch and provides increased load to failure at the tibial point of fixation compared with a standard monoblock Achilles allograft construct.
Controlled laboratory study.
Eight matched pairs of Achilles allograft tendons were secured to 8 matched pairs of fresh-frozen human cadaveric tibiae. Group 1 consisted of single-block grafts (n = 8), and group 2 included the split stacked grafts (n = 8). The cross-sectional area of each graft's 2 collagenous bundles was measured with a micrometer. The graft constructs were pulled to ultimate failure at a rate of 50 mm/min on a materials testing machine.
The mean cross-sectional area of the group 2 split stacked grafts (76.6 +/- 3.1 mm(2)) was significantly greater than that of the group 1 single-block grafts (48.2 +/- 3.0 mm(2); P =.00006). The maximum load to failure of the group 2 construct was significantly greater (1383 +/- 102 N) than that of the group 1 single-block configuration (1020 +/- 136 N; P =.01).
These results indicate that the novel split stacked configuration of an Achilles tendon allograft provides a greater cross-sectional area of graft material across the joint as well as a significant increase in the overall load to failure strength compared with a standard monoblock Achilles allograft construct.
The split stacked Achilles graft is an efficient method for using the entire allograft. With maintenance and use of all collagen fibers, the split stacked Achilles construct provides essentially 2 grafts in 1 while only using a single tibial tunnel.
尸体研究表明，双束重建能更好地复制后交叉韧带的原始解剖结构。随着目前同种异体跟腱后交叉韧带重建的趋势，确定具有最高拉伸和拔出强度的移植物构型的需求变得至关重要。
与标准整块同种异体跟腱移植物构型相比，劈开堆叠的同种异体跟腱移植物构建体能提供更多的移植物材料穿过切口，并在胫骨固定点增加至失效的负荷。
对照实验室研究。
将八对匹配的同种异体跟腱固定到八对新鲜冷冻的人体尸体胫骨上。第1组由整块移植物组成（n = 8），第2组包括劈开堆叠移植物（n = 8）。用测微计测量每个移植物的两条胶原束的横截面积。在材料试验机上以50毫米/分钟的速度将移植物构建体拉至最终失效。
第2组劈开堆叠移植物的平均横截面积（76.6±3.1平方毫米）显著大于第1组整块移植物的平均横截面积（48.2±3.0平方毫米；P = 0.00006）。第2组构建体的最大失效负荷（1383±102牛）显著大于第1组整块构型的最大失效负荷（1020±136牛；P = 0.0
