METHODS: Twelve clean, healthy male New Zealand rabbits with a mass of (2 500±500) g were selected and randomly divided into a blank group and a control group with 6 rabbits in each group. In the control group, the rabbits were modeled with persistent strain injuries and ice compression, the general conditions of the rabbits and the active and passive activities of the shoulder joint were observed and their body weights were recorded. MRI was performed on the affected shoulder joints at 6 d and 29 d after modelling to observe the fluid and soft tissue;HE staining was used to observe the morphology of the rabbit biceps longus tendon and the synovial membrane of the joint capsule;Masson staining was used to observe the fibrous deposits of the rabbit biceps longus tendon and the synovial membrane of the joint capsule, and the fibrous deposits were analysed semi-quantitatively by Image J software.
RESULTS: Six days after the end of modeling, the active movement of the shoulder joints in the control group was limited, the passive movement was not significantly limited, and they walked with a limp;29 days after the end of the modeling, the active and passive movements of the shoulder joints in the model group were severely limited. Compared with the blank group (2.50±0.14) kg, the body weight of the model group (2.20±0.17) kg was significantly reduced(P<0.01). MRI showed that 6 days after modelling, the muscles around the shoulder joint were not smooth in shape, the joint capsule structure was narrowed and a large amount of fluid was seen in the joint cavity;29 days after modelling, the muscles around the shoulder joint were rough in shape, structure of the joint capsule was unclear and the fluid in the joint cavity was reduced compared with 6 days after modelling. Pathological staining showed that the long-headed biceps tendon fibres in the control group were disorganised, curled or even broken, and the synovial tissue of the joint capsule was heavily vascularised, with collagen fibre deposits and severe inflammatory cell infiltration. The fiber deposition of the long head of biceps brachii in the model group [(23.58±3.41)%, (27.56±3.70)%] and synovial tissue [(41.78±5.59)%, (62.19±7.54)%] were significantly higher than those in the blank group [(1.79±1.03) %, (1.29±0.63) %] at 7 and 30 days after modeling and synovial tissue fiber deposition [(8.15±3.61) %, (11.29±7.10) %], as shown by the semi-quantitative analysis of Masson staining results by Image J software. And the longer the time, the more severe the fibrosis (P<0.01).
CONCLUSIONS: The behavioral, imaging and pathological findings showed that the rabbit frozen shoulder model with persistent strain injuries and ice compression is consistent with the clinical manifestations and pathogenesis of periarthritis, making it an ideal method for periarthritis research.
方法:十二清洁,选取健康雄性新西兰大白兔(2500±500)g,随机分为空白组和对照组,每组6只。在对照组中,兔子以持续的劳损和冰压迫为模型,观察兔的一般情况和肩关节的主动和被动活动,并记录其体重。造模后6d和29d分别对患侧肩关节行MRI检查,观察液体和软组织;HE染色观察兔长肱二头肌肌腱和关节囊滑膜的形态;Masson染色观察兔长肱二头肌肌腱和关节囊滑膜的纤维沉积,并利用ImageJ软件对纤维状沉积物进行了半定量分析。
结果:建模结束后六天,对照组肩关节活动受限,被动运动没有明显限制,他们一瘸一拐地走着;建模结束29天后,模型组肩关节的主动和被动运动受到严重限制.与空白组(2.50±0.14)kg相比,模型组体重(2.20±0.17)kg明显减轻(P<0.01)。MRI显示建模后6天,肩关节周围的肌肉形状不光滑,关节囊结构变窄,关节腔内可见大量液体;建模后29天,肩关节周围的肌肉形状粗糙,与建模后6天相比,关节囊的结构不清楚,关节腔中的液体减少。病理染色显示,对照组长头二头肌肌腱纤维无组织,卷曲甚至破碎,关节囊的滑膜组织大量血管化,胶原纤维沉积和严重的炎症细胞浸润。模型组肱二头肌长头纤维沉积[(23.58±3.41)%,(27.56±3.70)%]和滑膜组织[(41.78±5.59)%,(62.19±7.54)%]明显高于空白组[(1.79±1.03)%,(1.29±0.63)%]造模后第7天和第30天滑膜组织纤维沉积[(8.15±3.61)%,(11.29±7.10)%],通过ImageJ软件对Masson染色结果进行半定量分析。时间越长,纤维化越严重(P<0.01)。
结论:行为,影像学和病理结果显示,兔肩周炎模型伴持续性劳损损伤和冰面压迫,使其成为研究关节炎的理想方法。