Differences in tendon graft healing between the intra-articular and extra-articular ends of a bone tunnel.
Differences in tendon graft healing between the intra-articular and extra-articular ends of a bone tunnel.
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DOI：
10.1007/s11420-008-9096-1
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发表时间：
2009-02-01
期刊：
影响因子：
--
通讯作者：
Rodeo, Scott A
中科院分区：
文献类型：
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作者：
Bedi, Asheesh;Kawamura, Sumito;Rodeo, Scott A
肌腱移植物和骨隧道之间愈合的基本生物学仍然不完全清楚。愈合肌腱-骨附着部位的形态学特征有明显的可变性。我们假设在手术创建的骨隧道的不同区域存在肌腱到骨愈合的空间和时间差异。24只雄性Sprague-Dawley大鼠采用悬吊骨膜固定固定下的指长屈肌腱移植物进行左膝前交叉韧带（ACL）重建。分别于术后4、7、11、14、21和28天处死动物，对关节内孔（IAA）、隧道中部和关节外孔（EAA）处的愈合端部进行常规组织学和免疫组织化学分析。6只动物分别于术后14天和28天采用双荧光标记法测定愈合骨隧道的矿物质附着率（MAR）。分别用von Kossa染色和Goldner-Masson三色染色评估钙化骨基质的总面积。愈合的肌腱-骨界面组织在IAA处显示宽的软骨基质，而在EAA处显示狭窄的纤维基质。在整个研究期间，除术后4天外，IAA处破骨细胞明显多于EAA处（p < 0.05）。随着时间的推移，肌腱移植物和骨隧道之间的胶原蛋白连续性增加，与IAA相比，EAA的肌腱和骨之间的胶原纤维连续性更平行。4周时EAA的MAR也显著升高（p < 0.001）。肌腱移植物和骨之间的愈合在骨隧道长度上存在显著差异。这些差异的病因在本质上可能是多因素的，包括隧道不同末端的可变生物和生物力学环境。了解这些差异可能最终使外科医生能够提高移植固定的质量和ACL重建后的长期预后。
The basic biology of healing between a tendon graft and bone tunnel remains incompletely understood. Distinct variability in the morphological characteristics of the healing tendon-bone attachment site has been reported. We hypothesized that spatial and temporal differences in tendon-to-bone healing exist at different regions of a surgically created bone tunnel. Twenty-four male, Sprague-Dawley rats underwent anterior cruciate ligament (ACL) reconstruction in the left knee using a flexor digitorum longus tendon graft secured using suspensory periosteal fixation. Animals were sacrificed at 4, 7, 11, 14, 21, and 28 days after surgery and prepared for routine histology and immunohistochemical analysis of the healing enthesis at the intra-articular aperture (IAA), mid-tunnel, and extra-articular aperture (EAA). Six animals were used to measure mineral apposition rate (MAR) along the healing bone tunnel by double fluorochrome labeling at 14 and 28 days after surgery. The total area of calcified bone matrix was assessed with von Kossa staining and Goldner-Masson trichrome staining, respectively. The healing tendon-bone interface tissue exhibited a wide chondroid matrix at the IAA, in contrast to a narrow, fibrous matrix at the EAA. There were significantly more osteoclasts at the IAA compared to EAA throughout the study period, except 4 days after surgery (p < 0.05). Collagen continuity between the tendon graft and bone tunnel increased over time, with a more parallel orientation and increased collagen fiber continuity between tendon and bone at the EAA compared to the IAA. MAR was also significantly greater at the EAA at 4 weeks (p < 0.001). Significant differences in healing between the tendon graft and bone exist along the length of bone tunnel secured with suspensory fixation. The etiology of these differences is likely multifactorial in nature, including variable biological and biomechanical environments at different ends of the tunnel. Understanding these differences may ultimately allow surgeons to improve the quality of graft fixation and long-term outcomes after ACL reconstruction.