Lemmon Elisabeth A, Locke Ryan C, Szostek Adrianna K, Ganji Elahe, Killian Megan L
a Department of Animal and Food Sciences and Biomedical Engineering , University of Delaware , Newark , DE , USA.
b Department of Biomedical Engineering , University of Delaware , Newark , DE , USA.
Connect Tissue Res. 2018 Sep;59(5):437-446. doi: 10.1080/03008207.2018.1485666. Epub 2018 Jul 2.
Identify the healing outcomes following a partial-width, full-thickness injury to the rotator cuff tendon-bone attachment and establish if the adult attachment can regenerate the morphology of the healthy attachment.
We hypothesized that a partial-width injury to the attachment would heal via fibrosis and bone remodeling, resulting in increased cellularity and extra-cellular matrix deposition, reduced bone volume (BV), osteoclast presence, and decreased collagen organization compared to shams.
A partial-width injury was made using a biopsy punch at the center one-third of the rat infraspinatus attachment. Contralateral limbs underwent a sham operation. Rats were sacrificed at 3 and 8 weeks after injury for analyses. Analyses performed at each time point included cellularity (Hematoxylin & Eosin), ECM deposition (Masson's Trichrome), BV (micro-computed tomography; microCT), osteoclast activity (Tartrate Resistant Acid Phosphatase; TRAP), and collagen fibril organization (Picrosirius Red). Injured and sham shoulders were compared at both 3 and 8 weeks using paired, two-way ANOVAs with repeated measures (Sidak's correction for multiple comparisons).
Cellularity and ECM deposition increased at both 3 and 8 weeks compared to sham contralateral attachments. BV decreased and osteoclast presence increased at both 3 and 8 weeks compared to sham contralateral limbs. Collagen fibril organization was reduced at 3 weeks after injury compared to 3-week sham attachments.
These findings suggest that a partial-width injury to the rotator cuff attachment does not fully regenerate the native structure of the healthy attachment. The injury model healed via scar-like fibrosis and did not propagate into a full-width tear after 8 weeks of healing.
确定肩袖肌腱 - 骨附着处部分厚度全层损伤后的愈合结果，并确定成年附着处能否再生出健康附着处的形态。
我们假设附着处的部分厚度损伤会通过纤维化和骨重塑愈合，与假手术组相比，会导致细胞增多和细胞外基质沉积增加、骨体积（BV）减少、破骨细胞出现以及胶原组织减少。
使用活检穿刺器在大鼠冈下肌附着处的中三分之一处造成部分厚度损伤。对侧肢体进行假手术。在损伤后3周和8周处死大鼠进行分析。每个时间点进行的分析包括细胞增多情况（苏木精和伊红染色）、细胞外基质沉积（马松三色染色）、BV（微型计算机断层扫描；microCT）、破骨细胞活性（抗酒石酸酸性磷酸酶；TRAP）以及胶原纤维组织（天狼星红染色）。在3周和8周时，使用重复测量的配对双向方差分析（Sidak多重比较校正）对受伤肩部和假手术肩部进行比较。
与对侧假手术附着处相比，在3周和8周时细胞增多和细胞外基质沉积均增加。与对侧假手术肢体相比，在3周和8周时BV减少且破骨细胞出现增加。与3周假手术附着处相比，损伤后3周时胶原纤维组织减少。
这些发现表明，肩袖附着处的部分厚度损伤不能完全再生出健康附着处的天然结构。损伤模型通过瘢痕样纤维化愈合，在愈合8周后未发展为全层撕裂。
