Kanazawa Tomonoshin, Gotoh Masafumi, Ohta Keisuke, Shiba Naoto, Nakamura Kei-Ichiro
Division of Microscopic and Development Anatomy, Department of Anatomy, Kurume University School of Medicine, 67 Asahi-machi, Kurume City, Fukuoka, 830-0011, Japan.
Department of Orthopaedic Surgery, Kurume University School of Medicine, 67 Asahi-machi, Fukuoka, Kurume City, Fukuoka, 830-0011, Japan.
J Orthop Res. 2016 Jun;34(6):969-76. doi: 10.1002/jor.23111. Epub 2015 Dec 10.
To obtain a successful outcome after rotator cuff repair, the repaired tendon must be biologically anchored to the bone. However, the histological structure at the repaired tendon-bone interface differs from that of the site of normal tendon insertion. Therefore, analyzing postnatal development in detail will contribute to understanding the repaired tendon-bone interface after rotator cuff repair. In this study, we analyzed postnatal development at the tendon-bone insertion in terms of temporal changes in SOX9/SCX expression and three-dimensional (3D) ultrastructure with FIB/SEM tomography, a new scanning electron microscopic method. Sixteen postnatal Sprague-Dawley rats were used for the study. One-, two-, three-, and four-week-old rats were sacrificed and both right and left shoulders were removed; eight normal supraspinatus tendon insertions were isolated for each time point. At each time point, four specimens were evaluated with fluorescent immunostaining for SOX9/SCX expression, and the remaining four specimens were evaluated with FIB/SEM tomography. Even in postnatal development, SOX9(+) /SCX(+) expression was observed at the tendon insertion; expression gradually decreased with postnatal development at the normal tendon insertion. In 3D ultrastructure, the morphology of the cells and the number/orientation of the cell processes drastically changed by postnatal week 4. The pattern of SOX9/SCX expression and 3D ultrastructural changes obtained in this study contribute to an understanding of the complicated development of normal tendon-bone insertion. Therefore, this study helps elucidate the pathophysiology of tendon-bone insertion, especially in cases of rotator cuff tear and repair. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:969-976, 2016.
为了在肩袖修复后获得成功的结果，修复后的肌腱必须在生物学上与骨骼固定。然而，修复后的肌腱 - 骨界面的组织学结构与正常肌腱附着部位不同。因此，详细分析出生后的发育情况将有助于理解肩袖修复后修复的肌腱 - 骨界面。在本研究中，我们通过一种新的扫描电子显微镜方法——聚焦离子束/扫描电子显微镜断层扫描，从SOX9/SCX表达的时间变化和三维（3D）超微结构方面分析了肌腱 - 骨附着处的出生后发育情况。16只出生后的Sprague-Dawley大鼠用于该研究。处死1周、2周、3周和4周龄的大鼠，并切除左右肩部；每个时间点分离出8个正常的冈上肌腱附着处。在每个时间点，4个标本用荧光免疫染色评估SOX9/SCX表达，其余4个标本用聚焦离子束/扫描电子显微镜断层扫描评估。即使在出生后的发育过程中，在肌腱附着处也观察到SOX9(+) /SCX(+)表达；在正常肌腱附着处，随着出生后发育，表达逐渐降低。在3D超微结构中，到出生后第4周，细胞形态以及细胞突起的数量/方向发生了剧烈变化。本研究中获得的SOX9/SCX表达模式和3D超微结构变化有助于理解正常肌腱 - 骨附着的复杂发育过程。因此，本研究有助于阐明肌腱 - 骨附着的病理生理学，尤其是在肩袖撕裂和修复的情况下。© 2015骨科研究协会。由Wiley Periodicals, Inc.出版。《矫形外科研究杂志》34:969 - 976, 2016年。
