Lee Hyo-Jin, Kim Yang-Soo, Ok Ji-Hoon, Lee Yun-Kyoung, Ha Michelle Y
Department of Orthopedic Surgery, Seoul St. Mary's Hospital, The Catholic University of Korea, 505 Banpo-dong Seocho-gu, Seoul, 137-701, Korea.
Knee Surg Sports Traumatol Arthrosc. 2015 Feb;23(2):555-61. doi: 10.1007/s00167-013-2395-1. Epub 2013 Jan 31.
This study examined the early effect of a subacromial steroid injection on injured rotator cuff tendon.
Forty rats were allocated into two groups: a steroid injection (group 1) and no injection as control (group 2). A full-thickness defect was made at the unilateral infraspinatus tendon in both groups. A single dose of methylprednisolone was injected in steroid group. The tendon was harvested at 1, 3, 7, 14, and 42 days after surgery; gene expression and immunohistochemical study were performed for type-I/III collagen, tumour necrosis factor (TNF)-α, and extracellular matrix molecules.
The type-III to type-I collagen ratio was at 7 days higher in the steroid group than that in the control group and decreased to the control level at 14 days and was maintained until 42 days. The general expression of the MMPs and TIMPs between two groups showed similar pattern regardless of the steroid injection. The gene expression of aggrecan and fibronectin in the steroid group was significantly higher than that in the control group (p < 0.05) at 3 days after surgery. They decreased to the equal level with control group at 7 days after surgery. Both groups showed no significant difference between aggrecan and fibronectin until 42 days after surgery (n.s.).
A subacromial steroid injection may alter the collagen composition and extracellular matrix and interfere with the healing process in an acute tear of rat infraspinatus tendon at the early phase after the injection. However, these alterations seem to become normalized after the early inflammatory healing phase.
本研究探讨肩峰下类固醇注射对损伤的肩袖肌腱的早期影响。
40只大鼠被分为两组：类固醇注射组（第1组）和不注射作为对照组（第2组）。两组大鼠均在单侧冈下肌腱制造全层缺损。类固醇组注射单剂量甲泼尼龙。术后1、3、7、14和42天采集肌腱；对I/III型胶原、肿瘤坏死因子（TNF）-α和细胞外基质分子进行基因表达和免疫组化研究。
类固醇组III型与I型胶原比率在7天时高于对照组，14天时降至对照水平并维持至42天。无论是否注射类固醇，两组间基质金属蛋白酶（MMPs）和基质金属蛋白酶组织抑制因子（TIMPs）的总体表达模式相似。术后3天时，类固醇组聚集蛋白聚糖和纤连蛋白的基因表达显著高于对照组（p<0.05）。术后7天时降至与对照组相同水平。术后42天时，两组聚集蛋白聚糖和纤连蛋白之间均无显著差异（无统计学意义）。
肩峰下类固醇注射可能会改变大鼠冈下肌腱急性撕裂早期注射后的胶原组成和细胞外基质，并干扰愈合过程。然而，这些改变在早期炎症愈合期后似乎会恢复正常。
