Saikku-Bäckström A, Tulamo R M, Räihä J E, Kellomäki M, Toivonen T, Törmälä P, Rokkanen P
Faculty of Veterinary Medicine, Helsinki University, Finland.
Biomaterials. 2001 Jan;22(1):33-43. doi: 10.1016/s0142-9612(00)00142-3.
Osteotomies of the femoral diaphysis were fixed with absorbable self-reinforced fibrillated poly-96L/4D-lactide (SR-PLA96) intramedullary rods (4.5 mm x 50-60 mm) in 43 adult rabbits. Follow-up times varied from 3 weeks to 3 yr. After sacrifice histological, oxytetracycline-fluorescence and microradiographic studies of the bones were performed. Strength characteristics and changes in crystallinity and molecular weight of the rods were also measured. All osteotomies were evaluated radiographically. Thirty-six osteotomies (84%) healed uneventfully. The implant disappeared almost totally within 3 yr and histology showed only a minor foreign body reaction. From 6 weeks on, the bending force needed to break the osteotomy was comparable to the bending force needed to break the control bone. The shear strength of the rods displayed only minor changes for the first 24 weeks. Subsequently, the rods rapidly lost their strength and at 48 weeks there was practically no shear strength left, which is ideal for healing of an osteotomy. The present investigation demonstrated, that absorbable. fibrillated SR-PLA96-rods can be used for the intramedullar fixation of simple cortical bone osteotomies in rabbits. These results have encouraged us to continue our studies with the fixation of experimental cortical bone osteotomies in larger species.
在43只成年兔子中，股骨干截骨术采用可吸收的自增强原纤化聚96L/4D-丙交酯（SR-PLA96）髓内棒（4.5毫米×50 - 60毫米）进行固定。随访时间从3周至3年不等。处死后，对骨骼进行了组织学、土霉素荧光和显微放射学研究。还测量了棒的强度特性以及结晶度和分子量的变化。所有截骨术均进行了放射学评估。36例截骨术（84%）顺利愈合。植入物在3年内几乎完全消失，组织学显示仅有轻微的异物反应。从6周起，折断截骨处所需的弯曲力与折断对照骨所需的弯曲力相当。在前24周，棒的抗剪强度仅有轻微变化。随后，棒迅速失去强度，在48周时几乎没有抗剪强度了，这对于截骨术的愈合是理想的。本研究表明，可吸收的原纤化SR-PLA96棒可用于兔子简单皮质骨截骨术的髓内固定。这些结果鼓励我们继续进行在更大动物身上固定实验性皮质骨截骨术的研究。
