Pyhältö Tuomo, Lapinsuo Matti, Pätiälä Hannu, Niiranen Henna, Törmälä Pertti, Rokkanen Pentti
Department of Orthopaedics and Traumatology, Helsinki University Central Hospital and University of Helsinki, Finland.
J Biomater Sci Polym Ed. 2005;16(6):725-44. doi: 10.1163/1568562053992513.
Two self-reinforced poly(L/DL)lactide 70:30 or self-reinforced poly (L/DL)lactide 70:30/ bioactive glass (SR-P(L/DL)LA/bioactive glass) composite rods (2 mm x 40 mm) were implanted into the dorsal subcutaneous tissue and osteotomies of the distal femur were fixed with these rods (2 mm x 26 mm) in 36 rabbits. The follow-up times varied from 3 to 100 weeks. After the animals were killed, three-point bending and shear tests and molecular weight measurements were performed for subcutaneously placed rods. Radiological, histological, histomorphometrical, microradiographic and oxytetracycline-fluorescence studies of the osteotomized and intact control femora were performed. After 12 weeks the SR-P(L/DL)LA rods had fragmented into pieces and the mechanical properties could not be measured. The SR-P(L/DL)LA/bioactive glass rods lost their mechanical properties slower, and at 24 weeks the bending strength had decreased by 39% and the shear strength by 50%. After that the mechanical properties of the SR-P(L/DL)LA/bioactive glass rods could not be measured. All osteotomies healed well, and no gross signs of inflammatory reactions were observed. One slight displacement was seen in the three-week follow-up group with SR-P(L/DL)LA rods. Signs of resorption of the implants were seen after 48 weeks in the SR-P(L/DL)LA group and after 24 weeks in the SR-P(L/DL)LA/bioactive glass group. The SR-P(L/DL)LA/bioactive glass rods were almost totally resorbed from the bone at 100 weeks. The present investigation showed that the mechanical strength and fixation properties of the SR-P(L/DL)LA and the SR-P(L/DL)LA/bioactive glass composite rods are suitable for fixation of cancellous bone osteotomies in rabbits.
将两根聚（L/DL）丙交酯70:30自增强棒或聚（L/DL）丙交酯70:30/生物活性玻璃自增强复合棒（2毫米×40毫米）植入36只兔子的背部皮下组织，并使用这些棒（2毫米×26毫米）固定股骨远端的截骨部位。随访时间从3周到100周不等。在处死动物后，对皮下放置的棒进行三点弯曲试验、剪切试验和分子量测量。对截骨的和完整的对照股骨进行放射学、组织学、组织形态计量学、显微放射学和土霉素荧光研究。12周后，聚（L/DL）丙交酯70:30自增强棒已破碎成碎片，无法测量其力学性能。聚（L/DL）丙交酯70:30/生物活性玻璃复合棒力学性能丧失较慢，在24周时弯曲强度下降了39%，剪切强度下降了50%。此后，聚（L/DL）丙交酯70:30/生物活性玻璃复合棒的力学性能无法测量。所有截骨均愈合良好，未观察到明显的炎症反应迹象。在聚（L/DL）丙交酯70:30自增强棒的3周随访组中观察到一处轻微移位。在聚（L/DL）丙交酯70:30组中，48周后可见植入物吸收迹象；在聚（L/DL）丙交酯70:30/生物活性玻璃组中，24周后可见植入物吸收迹象。在100周时，聚（L/DL）丙交酯70:30/生物活性玻璃复合棒几乎完全从骨中吸收。本研究表明，聚（L/DL）丙交酯70:30自增强棒和聚（L/DL）丙交酯70:30/生物活性玻璃复合棒的力学强度和固定性能适用于兔松质骨截骨的固定。
