ABSTRACT
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 classification, 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 fixation of the fracture. Results The peak load (443.10 ± 8.54) N of group A was not significantly different from that of group C (457.00 ± 26.53) N (P > 0.05), but significantly 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 significantly better than that of cannulated compression screw and suture, and compared with the cannulated ompression screw, it is difficult to cause intercondylar fossa impingement.