双头空心加压螺钉固定前交叉韧带胫骨止点撕脱骨折的生物力学研究

Biomechanical study of tibial avulsion fracture of anterior cruciate ligament with double-headed cannulated compression screw

目的探究双头空心加压螺钉固定前交叉韧带(ACL)胫骨止点撕脱骨折的生物力学效果及减少髁间窝撞击风险的可能性。方法以猪膝关节(30例)作为实验样本。参照Meyers分型,将其制成Ⅲ型骨折。按随机数字表法分为A组(双头空心加压螺钉)、B组(空心拉力螺钉)及C组(缝线),每组10例。通过检测初始位移和失效负载(峰值负载及屈服负载),观察螺帽埋入骨块情况及失效类型,以探究双头空心加压螺钉固定该骨折的生物力学特性。结果 A组的峰值负载(443.10±8.54)N与C组(457.00±26.53)N差异无统计学意义(P>0.05),但明显大于B组的峰值负载(361.70±18.76)N,差异有统计学意义(P<0.05)。A组的屈服负载明显大于B组的屈服负载(P<0.05),但明显小于C组的屈服负载(P<0.05)。A组样本的初始位移(1.38±0.14)mm均明显短于B、C两组(1.94±0.12)和(3.98±0.19)mm,差异有统计学意义(P<0.05)。A组样本的螺帽均埋入骨块内,B组样本的螺帽均明显突出于ACL实质。结论双头空心加压螺钉固定ACL胫骨止点撕脱骨折的早期生物力学强度明显优于空心拉力螺钉及缝线固定,且与空心拉力螺钉相比不易造成髁间窝撞击。

Objective To investigate the biomechanical effects of double-headed cannulated compression screws for tibial avulsion fracture of anterior cruciate ligament and the possibility of reducing the risk of intercondylar fossa impingement. Methods Porcine knee joints （30 cases） were taken as experimental samples. Referring to the Meyers classifcation, it is made into type Ⅲ fracture. According to the random number table method, they were divided into group A （double-headed cannulated compression screw）, group B （cannulated compression screw） and group C （suture）, with 10 samples in each group. By detecting the initial displacement and the failure load （peak load and yield load）, the nut embedded in the bone block and the failure type were observed to investigate the biomechanical characteristics of the double headed cannulated screw fxation of the fracture. Results The peak load （443.10 ± 8.54） N of group A was not signifcantly different from that of group C （457.00 ± 26.53） N （P 〉 0.05）, but signifcantly higher than that of group B （361.70 ± 18.76） N （P 〈 0.05）. The yield load of group A is obviously larger than that of group B （P 〈 0.05）, but it is obviously smaller than the yield load of group C （P 〈 0.05）. The initial displacement of the group A （1.38 ± 0.14） mm was shorter than that of group B and C （1.94 ± 0.12） mm, （3.98 ± 0.19） mm （P 〈 0.05）. The nuts of group A were embedded in the fracture block, and the nuts of group B obviously protruded from the ACL. Conclusions The early biomechanical strength of the anterior cruciate ligament tibial avulsion fracture was signifcantly better than that of cannulated compression screw and suture, and compared with the cannulated ompression screw, it is diffcult to cause intercondylar fossa impingement.