Enhancement of tendon-bone integration of anterior cruciate ligament grafts with bone morphogenetic protein-2 gene transfer - A histological and biomechanical study
Enhancement of tendon-bone integration of anterior cruciate ligament grafts with bone morphogenetic protein-2 gene transfer - A histological and biomechanical study
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DOI：
10.2106/00004623-200207000-00005
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发表时间：
2002-07-01
影响因子：
5.3
通讯作者：
Huard, J
中科院分区：
文献类型：
--
作者：
Martinek, V;Latterman, C;Huard, J
背景：肌腱移植物用于置换前交叉韧带的整合有时仍不令人满意，可能与术后前后位松弛有关。本研究旨在探讨骨形态发生蛋白-2(BMP-2)基因转移对兔前交叉韧带重建后肌腱-骨界面半腱肌腱移植物整合的影响。方法：将成年新西兰大白兔前交叉韧带移植为自体双束半腱肌腱。半腱肌腱移植物经腺病毒-荧光素酶、腺病毒-LacZ(AdLacZ)或腺病毒-BMP-2(AdBMP-2)体外感染，未处理的移植物作为对照。在术后2周、4周、6周和8周对移植物进行组织学检查。在其他实验中，从术后8周处死的动物的股骨-前十字韧带移植物-胫骨复合体的结构特性通过单轴测试来确定。结果：基因工程半腱肌腱移植物在体外表达报告基因和BMP-2。AdLacZ感染的移植物表现出两种不同的转导组织模式。在关节内，感染细胞大多沿表面排列，术后2-8周数量减少。在移植物的隧道内部分，感染细胞的数量在观察期内没有减少。此外，在肌腱的深层发现了大量的转导细胞。对照组肌腱-骨界面处的肉芽组织逐渐重组为致密的结缔组织，随后形成类似于Sharpey纤维的纤维。在AdBMP-2感染的前交叉韧带移植标本中，术后4周在肌腱-骨界面处已形成一大片类似软骨-骨样的基质。这一区域在6周时增加，显示从骨向矿化软骨和非矿化纤维软骨过渡。此外，在AdBMP-2处理的标本中，骨隧道中的肌腱-骨界面类似于正常的前交叉韧带附着处。与对照组相比，转导AdBMP-2的移植物的刚度(29.0+/-7.1N/mm比16.7+/-8.3N/mm)和极限载荷(108.8+/-50.8N比45.0+/-18.0N)显著提高(p<；结论：BMP-2基因转移显著改善了兔前交叉韧带重建后半腱肌腱移植物在骨隧道内的整合。临床意义：包括基因治疗和组织工程在内的新技术，如本研究中描述的技术，可能为促进前交叉韧带重建后的生物愈合提供有用的治疗方法。
Background: The integration of tendon grafts used for replacement of the anterior cruciate ligament is still sometimes unsatisfactory and may be associated with postoperative anterior-posterior laxity. The goal of this study was to examine the capacity of bone morphogenetic protein-2 (BMP-2) gene transfer to improve the integration of semitendinosus tendon grafts at the tendon-bone interface after reconstruction of the anterior cruciate ligament in rabbits.Methods: The anterior cruciate ligaments of adult New Zealand White rabbits were replaced with autologous double-bundle semitendinosus tendon grafts. The semitendinosus tendon grafts had been infected in vitro with adenovirus-luciferase, adenovirus-LacZ (AdLacZ), or adenovirus-BMP-2 (AdBMP-2); untreated grafts served as controls. The grafts were examined histologically at two, four, six, and eight weeks after surgery. In additional experiments, the structural properties of the femur-anterior cruciate ligament graft-tibia complexes, from animals killed eight weeks postoperatively, were determined from uniaxial tests. The stiffness (N/mm) and ultimate load to failure (N) were determined from the resulting load-elongation curves.Results: Genetically engineered semitendinosus tendon grafts expressed reporter genes as well as BMP-2 in vitro. The AdLacZ-infected grafts showed two different histological patterns of transduction. Intra-articularly, infected cells were mostly aligned along the surface, and they decreased in number between two and eight weeks after Surgery. In the intra-tunnel portions of the grafts, the number of infected cells did not decrease during the observation period. Moreover, a high number of transduced cells was found in the deeper layers of the tendons. In the control group, granulation-type tissue at the tendon-bone interface showed progressive reorganization into a dense connective tissue, and a later establishment of fibers resembling Sharpey fibers. In the specimens with an AdBMP-2-infected anterior cruciate ligament graft, a broad zone of newly formed matrix resembling chondro-osteoid had formed at the tendon-bone interface at four weeks after surgery. This area was increased at six weeks, showing a transition from bone to mineralized cartilage and nonmineralized fibrocartilage. In addition, in the AdBMP-2-treated specimens, the tendon-bone interface in the osseous tunnel was similar to that of a normal anterior cruciate ligament insertion. The stiffness (29.0 +/- 7.1 N/mm compared with 16.7 +/- 8.3 N/mm) and the ultimate load to failure (108.8 +/- 50.8 N compared with 45.0 +/- 18.0 N) were significantly enhanced in the specimens with an AdBMP-2-transduced graft when compared with the control values (p < 0.05).Conclusion: This study demonstrates that BMP-2 gene transfer significantly improves the integration of semitendinosus tendon grafts in bone tunnels after reconstruction of the anterior cruciate ligament in rabbits.Clinical Relevance: Novel technologies including gene therapy and tissue engineering, such as those described in this study, may provide useful therapeutic procedures to enhance biological healing after reconstruction of the anterior cruciate ligament.