聚乳酸螺钉对骨折愈合影响的实验研究

The Effect of Polylactide Screws on Fracture Healing

本实验旨在研究一种自制PDLLA螺钉对骨折愈合的影响。用自制粘均分子量达 43× 10 4 的PDLLA螺钉内固定治疗 8只犬股骨外髁骨折 ,并以金属螺钉固定为对照。动物术后 2、4、8、12周处死 ,观察骨组织愈合影响的光镜和扫描电镜表现。光镜示两组骨折 2周时形成大量纤维性骨痂 ,12周时都已顺利愈合 ,实验组成骨过程明显较对照组缓慢 ,但成骨活动正常。扫描电镜示两组胶原纤维都排列规则 ,12周时顺利钙化成骨 ,实验组 12周时见大小不等 ,高电子密度颗粒。因而临床上应当适用于血供丰富部位骨折。

This experiment aimed at investigating the effect of a kind of home bred poly DL lactide screws on fracture healing. An operation was performed so as to make bilateral lateral condylar fractures of the femur in 8 dogs. The left sides were fixed with 2 home bred PDLLA(Mv=43×10 4) screws, and the contralateral sides were fixed with 2 metalic screws to be used as controls. The animals were sacrificed at 2, 4, 8, and 12 weeks after surgery. Optic microscopy and SEM photography were done. The results of optic microscopy showed that fibrous callus formed already in both groups by 2 weeks after surgery, and bilateral fractures united uneventfully by 12 weeks. Although the course of fracture healing in experimemtal group was slower than that in control group, the osteogensis in experimental group appeared to be normal. The SEM examination demonstrated that collagenous fibers arranged regularly and calcified normally in both groups at 12 weeks. And many square and rhomboid granules produced from the degradation of PDLLA material were found in experimental group at 12 weeks. Therefore, it is suggested that this kind of home bred PDLLA screws should be applicable to fractures where the tissues are rich in blood supply.