Meinig R P, Rahn B, Perren S M, Gogolewski S
AO/ASIF Research Institute, Davos, Switzerland.
J Orthop Trauma. 1996;10(3):178-90. doi: 10.1097/00005131-199604000-00006.
Tubular poly(L-lactide) membranes with a pore size of 5-15 microns and a molecular weight of 70,000 Daltons were implanted into 24 New Zealand skeletally mature rabbits to cover 10-mm mid-diaphyseal defects of the radius of the forelimb. An identical defect on the contralateral limb was not treated with the membrane and served as a control. The animals were killed at 1, 2, 4, 8, 12, 24, 36, and 64 weeks after implantation, and radiographic and microscopic studies were conducted. The canals of the polymeric tubes were initially filled with blood. At 2 weeks, there was direct woven bone formation within the polymeric tube in continuity with the fragment cortices and its medullary canal. The formation of woven bone across the defect progressed until reconstruction of the defect had occurred at 6-8 weeks. The bone continued to remodel throughout the observation period of 64 weeks. By 12 weeks, bone within the lumen of the implant consisted of cancellous bone and cortical bone lining the membrane walls. At 24, 36, and 64 weeks, the implants were filled with cancellous bone and cortical bone in direct apposition to the polymer membrane. For one implant, the newly formed woven bone had only incompletely filled the defect at 8 weeks. This resulted in a nonunion with a residual gap of 0.5 mm and the appearance of mature bone. There was extensive bone formation along the intraosseous membrane in both control and implanted defects, although the untreated defects were rapidly filled with overlying muscle and soft tissues. The osseous activity of the untreated defects appeared confined to the bone ends by the interposed muscle and fibrous soft-tissue margins. The untreated defects resulted in radial-ulnar synostosis along the intraosseous membrane with cortical bone caps at the bone ends. The poly(L-lactide) membrane remained intact throughout the 64-week period without evidence of significant degradation. The membranes were encapsulated in a thin fibrous tissue. There was no histological evidence of acute or chronic inflammation associated with the implants.
将孔径为5 - 15微米、分子量为70,000道尔顿的管状聚（L - 丙交酯）膜植入24只骨骼成熟的新西兰兔体内，以覆盖前肢桡骨骨干中部10毫米的缺损。对侧肢体相同的缺损未用该膜处理，作为对照。在植入后1、2、4、8、12、24、36和64周处死动物，并进行影像学和显微镜研究。聚合物管的管腔最初充满血液。2周时，聚合物管内有直接的编织骨形成，与骨折碎片皮质及其髓腔连续。跨越缺损的编织骨形成持续进行，直到6 - 8周时缺损重建。在64周的观察期内，骨持续重塑。到12周时，植入物管腔内的骨由松质骨和衬于膜壁的皮质骨组成。在24、36和64周时，植入物充满松质骨和皮质骨，与聚合物膜直接并置。对于一个植入物，新形成的编织骨在8周时仅不完全填充缺损。这导致了骨不连，残留间隙为0.5毫米，并出现了成熟骨。在对照和植入缺损处，沿骨内膜均有广泛的骨形成，尽管未处理的缺损迅速被覆盖的肌肉和软组织填充。未处理缺损的骨活性似乎被插入的肌肉和纤维软组织边缘限制在骨端。未处理的缺损导致沿骨内膜的桡尺骨融合，并在骨端有皮质骨帽。聚（L - 丙交酯）膜在整个64周期间保持完整，没有明显降解的迹象。膜被包裹在一层薄纤维组织中。没有组织学证据表明与植入物相关的急性或慢性炎症。
