两种改性可吸收界面螺钉重建前交叉韧带的生物力学研究

摘要

目的：探索两种改性可吸收界面螺钉聚乳酸/羟基磷灰石/α-Fe2 O3（PLLA/ HA/α-Fe2 O3）和聚乳酸-聚乙二醇/羟基磷灰石（PLLA-PEG/ HA）重建前交叉韧带（anterior cruciate ligament，ACL）早期是否能满足对移植物固定的初始力学要求。方法猪胫骨及游离的猪伸趾肌腱被随机分为3组，每组包括8个胫骨及8个伸趾肌腱，分别应用 PL-LA/ HA/α-Fe2 O3、PLLA-PEG/ HA 及临床使用聚乳酸/羟基磷灰石（BioRCI-HA，Smith ﹠ Nephew，USA）三种界面螺钉对胫骨端移植物进行挤压固定。移植物固定完成后对三组实验样本实施生物力学测试，包括最大载荷、刚度和失败模式。结果最大载荷：BioRCI-HA 组为（483.4±103.8）N，PLLA/ HA/α-Fe2 O3组为（456.0±102.0）N，PLLA-PEG/ HA组为（445.7±90.1）N，三组最大载荷差异无统计学意义。抗拉刚度：BioRCI-HA 组（48.0±6.7）N/ mm ﹥ PLLA-PEG/HA 组（40.7±6.7）N/ mm 和 PLLA/ HA/α-Fe2 O3组（41.2±4.6）N/ mm，前者抗拉强度较后两者差异有统计学意义。失败模式：所有样本测试失败模式均为移植物滑出，并无出现移植物撕裂或者固定装置损坏发生。结论改性界面螺钉 PLLA/ HA/α-Fe2 O3、PLLA-PEG/ HA 在重建猪 ACL 中能满足生物力学要求。%Objective To evaluate the biomechanical properties of soft-tissue grafts reconstructed anterior cruciate liga-ment(ACL)with two modified bioabsorbable interference screws,Poly-L-lactic acid/ hydroxyapatite/ α-Fe2 O3(PLLA/ HA/ α-Fe2 O3 )screw and Poly-L-lactic acid-polyethylene glycol/ hydroxyapatite( PLLA-PEG/ HA)screw. Methods Porcine tibia and hoof extensor tendons were divided into 3 matched groups with 8 tibia and 8 extensor tendons in each group. PLLA/ HA/ α-Fe2 O3 screws、PLLA-PEG/ HA screws and poly-L-lactic acid and hydroxyapatite(BioRCI-HA,Smith ﹠ Nephew,USA)screws were used for tibial fixation in soft-tissue grafts ACL reconstruction. All specimens were subjected to tensile loading,including load to failure,stiffness and mechanism of failure recorded. Results The mean load to failure were(483. 4 ± 103. 8)N in BioRCI-HA screw group,(456. 0 ± 102. 0)N in PLLA/ HA/ α-Fe2 O3 screw group,(445. 7 ± 90. 1)N in PLLA-PEG/ HA screw group. No statistically significant differences were noted in mean load to failure. The mean stiffness:BioRCI-HA screw (48. 0 ± 6. 7)N/ mm ﹥ PLLA-PEG/ HA screw(40. 7 ± 6. 7)N/ mm and PLLA/ HA/ α-Fe2 O3 screw(41. 2 ± 4. 6)N/ mm. BioRCI-HA screws showed a greater stiffness than PLLA-PEG/ HA screws and PLLA/ HA/ α-Fe2 O3 screws respectively. Mech-anism of failure recorded:no graft failure or fixation failure was observed in either testing. When testing for pull out failure,all grafts were slipped out. Conclusion In this porcine model,PLLA-PEG/ HA screws and PLLA/ HA/ α-Fe2 O3 screws provided comparable biomechanical strength with BioRCI-HA screw.