Weimann Andre, Zantop Thore, Rümmler Markus, Hassenpflug Joachim, Petersen Wolf
Department of Orthopaedic Surgery, Christian-Albrechts-University Kiel, Kiel, Germany.
Arthroscopy. 2003 Dec;19(10):1097-102. doi: 10.1016/j.arthro.2003.10.023.
We evaluated the initial bone-patellar tendon-bone (BPTB) graft fixation strength of biodegradable pins compared with interference screws in anterior cruciate ligament reconstruction using bovine knees.
Biomechanical in vitro study.
Ten BPTB grafts from human donors fixed with 2 biodegradable 2.7-mm pins (Rigid Fix; Ethicon, Mitek Division, Norderstedt, Germany) crossing the bone block perpendicular and 10 BPTB grafts fixed with conventional biodegradable interference screws (Absolute Absorbable Interference Screw; Innovasive Devices, Marlborough, MA) underwent ultimate single-cycle failure loading at a rate of 200 mm/min. The grafts were fixed to bovine tibia to simulate young human femoral bone density. Failure mode, displacement before failure, and ultimate failure load were tested with a testing machine. The pullout force was in line with the bone tunnel to simulate a worst case scenario.
The failure mode for cross pins was either fracture of the bone block (5 specimens) or fracture of the articular pin (5 specimens). The failure mode for interference screws was slippage past the screw in all specimens. In the single cycle loading test, the mean yield load for the biodegradable pins was 400.2 (+/- 122.4) N, maximum load, 524.6 (+/- 136.6) N, with a mean stiffness of 155.2 (+/- 32.4) N/mm. The yield load at failure for the interference screw was 402.7 (+/- 143.9) N, maximum load 515.7 (+/- 168.5) N with a mean stiffness of 168 (+/- 42) N/mm.
Fixation of a BPTB graft with 2 biodegradable 2.7-mm pins (Rigid Fix) leads to primary stability that is comparable to fixation with biodegradable interference screws.
我们使用牛膝关节评估了在交叉韧带重建中，可生物降解销钉与干涉螺钉相比的初始骨-髌腱-骨（BPTB）移植物固定强度。
生物力学体外研究。
将来自人类供体的10条BPTB移植物用2枚2.7毫米可生物降解销钉（Rigid Fix；Ethicon，Mitek Division，德国诺德施泰特）垂直穿过骨块进行固定，另外10条BPTB移植物用传统的可生物降解干涉螺钉（Absolute Absorbable Interference Screw；Innovasive Devices，马萨诸塞州马尔伯勒）进行固定，以200毫米/分钟的速率进行极限单周期失效加载。将移植物固定到牛胫骨上，以模拟年轻人类股骨的骨密度。使用试验机测试失效模式、失效前的位移和极限失效载荷。拔出力与骨隧道对齐，以模拟最坏情况。
交叉销钉的失效模式为骨块骨折（5个标本）或关节销骨折（5个标本）。干涉螺钉的失效模式在所有标本中均为螺钉滑移。在单周期加载试验中，可生物降解销钉的平均屈服载荷为400.2（±122.4）N，最大载荷为524.6（±136.6）N，平均刚度为155.2（±32.4）N/mm。干涉螺钉失效时的屈服载荷为402.7（±143.9）N，最大载荷为515.7（±168.5）N，平均刚度为168（±42）N/mm。
用2枚2.7毫米可生物降解销钉（Rigid Fix）固定BPTB移植物可产生与可生物降解干涉螺钉固定相当的初始稳定性。
