Weiler A, Richter M, Schmidmaier G, Kandziora F, Südkamp N P
Trauma and Reconstructive Surgery, Sports Traumatology and Arthroscopy Service, Charité, Campus Virchow-Clinic, Humboldt-University of Berlin, Germany.
Arthroscopy. 2001 Apr;17(4):353-9. doi: 10.1053/jars.2001.21531.
The EndoPearl (Linvatec, Largo, FL), a biodegradable device to augment the femoral interference screw fixation of hamstring tendon grafts has been developed. The first objective of this study was to compare the initial fixation strength of quadrupled hamstring tendons and biodegradable interference screw fixation with and without the application of the EndoPearl device. The second objective was to determine the influence of the EndoPearl device on the fatigue behavior under incremental cyclic loading conditions in a simulation of critical fixation conditions.
Biomechanical study.
Fresh human hamstring tendons were harvested and grafts were fixed with biodegradable poly-L-lactide interference screws. Twenty proximal calf tibias were used to compare the initial fixation strength of the study and the control group. In the study group, the EndoPearl device was secured to the graft using two No. 5 Ethibond sutures (Ethicon, Somerville, NJ). Specimens were loaded until failure in a materials testing machine. For cyclic testing, human hamstring tendons and 20 distal porcine femurs were used. Critical graft fixation conditions were simulated by increasing tunnel diameter 2 mm over the graft diameter. Grafts were loaded progressively in increments of 100 N until failure; 100 cycles were applied per load increment.
Graft fixation with the additional EndoPearl device had a significantly higher maximum load to failure (658.9 +/- 118.1 N v 385.9 +/- 185.6 N, P =.003) and stiffness (41.7 +/- 11 N/mm v 25.7 +/- 8.5 N/mm). Graft fixation with the EndoPearl device sustained a significant higher total number of cycles (388.5 +/- 125.6) compared with the control group (152.8 +/- 144.9, P =.002).
We demonstrated that the augmentation of a hamstring tendon graft with the EndoPearl device increases interference screw fixation strength significantly. Under dynamic loading conditions, specimens of the study group sustained substantially higher loads and a larger number of cycles, which indicates a greater resistance to graft slippage. The application of the EndoPearl device may also allow for a secure soft-tissue graft fixation with interference screws in cases of critical fixation conditions.
已研发出一种可生物降解的EndoPearl装置（林瓦特克公司，拉戈市，佛罗里达州），用于增强绳肌腱移植体的股骨干涉螺钉固定。本研究的首要目的是比较应用和不应用EndoPearl装置时，四倍绳肌腱与可生物降解干涉螺钉固定的初始固定强度。第二个目的是在模拟关键固定条件下，确定EndoPearl装置对递增循环加载条件下疲劳行为的影响。
生物力学研究。
采集新鲜人绳肌腱，并用可生物降解的聚-L-丙交酯干涉螺钉固定移植体。使用20根近端小腿胫骨比较研究组和对照组的初始固定强度。在研究组中，使用两根5号Ethibond缝线（伊西康公司，萨默维尔市，新泽西州）将EndoPearl装置固定于移植体上。在材料试验机上对标本加载直至失效。对于循环测试，使用人绳肌腱和20根远端猪股骨。通过将隧道直径比移植体直径增大2mm来模拟关键移植固定条件。移植体以100N的增量逐步加载直至失效；每个加载增量施加100个循环。
附加EndoPearl装置的移植体固定在最大失效载荷（658.9±118.1N对385.9±185.6N，P = 0.003）和刚度（41.7±11N/mm对25.7±8.5N/mm）方面显著更高。与对照组（152.8±144.9，P = 0.002）相比，使用EndoPearl装置的移植体固定承受的循环总数显著更高（388.5±125.6）。
我们证明，使用EndoPearl装置增强绳肌腱移植体可显著提高干涉螺钉固定强度。在动态加载条件下，研究组标本承受的载荷显著更高，循环次数更多，这表明对移植体滑动的抵抗力更强。在关键固定条件下，EndoPearl装置的应用还可实现干涉螺钉对软组织移植体的牢固固定。
