Abstract：
To enhance the healing of tendon to bone, various biomimetically hierarchical scaffolds have been proposed. However, the fabrication of such scaffolds is complicated. Furthermore, the most significant result after a routine repair is loss of the transition zone between the tendon and bone, whose main components are similar to fibrocartilage.
To compare tendon-to-bone healing results in a rabbit model using a monophasic graft (decellularized fibrocartilage graft; DFCG) and hierarchical graft (decellularized tendon-to-bone complex; DTBC) that contain the native hierarchical enthesis.
Controlled laboratory study.
DFCG and DTBC were harvested from allogenic rabbits. A rabbit model of a chronic rotator cuff tear was established, and 3 groups were assessed: direct repair or repair with DFCG or DTBC fixed between the tendon and bone. Hierarchical evaluations of the repaired tendon-to-bone interface were performed with regard to the tendon zone, transition zone, and bone zone using histological staining and micro-computed tomography scanning. Biomechanical analysis was performed to evaluate the general healing strength.
The healing results in the tendon zone exhibited no significant difference among the 3 groups at any time point. In the transition zone, the grade in the direct repair group was significantly lower than that in the DFCG and DTBC groups at 4 weeks, and the grade in the DFCG group was significantly lower than that in the DTBC group at this time point. However, any significant difference between the DFCG group and DTBC group could no longer be detected at 8 and 16 weeks, which was inconsistent with the results of the biomechanical analysis. Micro-computed tomography analysis showed no significant difference among the 3 groups with regard to bone mineral density at 16 weeks.
A monophasic DFCG was able to achieve enhanced tendon-to-bone healing similar to that with hierarchical DTBC over the long term, with regard to both histological and biomechanical properties.
Fabrication of a monophasic scaffold instead of a hierarchical scaffold to promote regeneration and remodeling of a transition zone, which was mainly composed of fibrocartilaginous matrix between the tendon and bone, may be sufficient to enhance tendon-to-bone healing.
To compare tendon-to-bone healing results in a rabbit model using a monophasic graft (decellularized fibrocartilage graft; DFCG) and hierarchical graft (decellularized tendon-to-bone complex; DTBC) that contain the native hierarchical enthesis.
Controlled laboratory study.
DFCG and DTBC were harvested from allogenic rabbits. A rabbit model of a chronic rotator cuff tear was established, and 3 groups were assessed: direct repair or repair with DFCG or DTBC fixed between the tendon and bone. Hierarchical evaluations of the repaired tendon-to-bone interface were performed with regard to the tendon zone, transition zone, and bone zone using histological staining and micro-computed tomography scanning. Biomechanical analysis was performed to evaluate the general healing strength.
The healing results in the tendon zone exhibited no significant difference among the 3 groups at any time point. In the transition zone, the grade in the direct repair group was significantly lower than that in the DFCG and DTBC groups at 4 weeks, and the grade in the DFCG group was significantly lower than that in the DTBC group at this time point. However, any significant difference between the DFCG group and DTBC group could no longer be detected at 8 and 16 weeks, which was inconsistent with the results of the biomechanical analysis. Micro-computed tomography analysis showed no significant difference among the 3 groups with regard to bone mineral density at 16 weeks.
A monophasic DFCG was able to achieve enhanced tendon-to-bone healing similar to that with hierarchical DTBC over the long term, with regard to both histological and biomechanical properties.
Fabrication of a monophasic scaffold instead of a hierarchical scaffold to promote regeneration and remodeling of a transition zone, which was mainly composed of fibrocartilaginous matrix between the tendon and bone, may be sufficient to enhance tendon-to-bone healing.
摘要：
■为了增强肌腱对骨骼的愈合，各种仿生分层支架已被提出。然而,这种支架的制造是复杂的。此外，常规修复后最重要的结果是肌腱和骨骼之间的过渡区丢失，其主要成分类似于纤维软骨。
■使用单相移植物（脱细胞纤维软骨移植物；DFCG）和分层移植物（脱细胞腱-骨复合物；DTBC）比较兔模型中的腱-骨愈合结果。
■对照实验室研究。
■从同种异体兔收获DFCG和DTBC。建立兔慢性肩袖撕裂模型,并对3组进行评估：直接修复或使用DFCG或DTBC固定在肌腱和骨骼之间进行修复。对于肌腱区，对修复的肌腱-骨界面进行了分层评估，过渡带,和骨区使用组织学染色和显微计算机断层扫描。进行生物力学分析以评估一般愈合强度。
■肌腱区的愈合结果在任何时间点3组间都没有显着差异。在过渡区,4周时,直接修复组的分级明显低于DFCG和DTBC组,在此时间点，DFCG组的分级明显低于DTBC组。然而,DFCG组和DTBC组之间的任何显著差异在8周和16周不再能检测到，这与生物力学分析的结果不一致。显微计算机断层扫描分析显示，在16周时，3组之间的骨矿物质密度没有显着差异。
■单相DFCG能够在长期内实现类似于分层DTBC的增强的腱-骨愈合，关于组织学和生物力学特性。
■制造单相支架而不是分层支架，以促进过渡区的再生和重塑，它主要由肌腱和骨骼之间的纤维软骨基质组成，可能足以增强腱-骨愈合。
■使用单相移植物（脱细胞纤维软骨移植物；DFCG）和分层移植物（脱细胞腱-骨复合物；DTBC）比较兔模型中的腱-骨愈合结果。
■对照实验室研究。
■从同种异体兔收获DFCG和DTBC。建立兔慢性肩袖撕裂模型,并对3组进行评估：直接修复或使用DFCG或DTBC固定在肌腱和骨骼之间进行修复。对于肌腱区，对修复的肌腱-骨界面进行了分层评估，过渡带,和骨区使用组织学染色和显微计算机断层扫描。进行生物力学分析以评估一般愈合强度。
■肌腱区的愈合结果在任何时间点3组间都没有显着差异。在过渡区,4周时,直接修复组的分级明显低于DFCG和DTBC组,在此时间点，DFCG组的分级明显低于DTBC组。然而,DFCG组和DTBC组之间的任何显著差异在8周和16周不再能检测到，这与生物力学分析的结果不一致。显微计算机断层扫描分析显示，在16周时，3组之间的骨矿物质密度没有显着差异。
■单相DFCG能够在长期内实现类似于分层DTBC的增强的腱-骨愈合，关于组织学和生物力学特性。
■制造单相支架而不是分层支架，以促进过渡区的再生和重塑，它主要由肌腱和骨骼之间的纤维软骨基质组成，可能足以增强腱-骨愈合。
