不同高度钝力打击致大鼠皮肤与骨骼肌挫伤的对比

Comparison of the Skin and Skeletal Muscle Contusion in Rats Induced by Blunt Force with Different Heights

目的探讨不同高度钝力打击下,皮肤与骨骼肌挫伤后的修复过程差异。方法采用自主设计的自由落体打击装置,以打击高度为主要损伤程度考量因素,将自由落体从15、30、50 cm高度打击造成SD大鼠下肢三种不同程度的挫伤。采用组织形态学方法观察损伤后6 h、24 h、3 d、7 d、13 d皮肤及肌肉的修复过程。结果三个打击高度引起实验大鼠下肢挫伤,基本都可形成皮下组织和(或)肌肉内的出血,在伤后24h内修复的过程基本类似,但表现程度随打击高度增加而明显;15 cm挫伤组在3 d时出血区红细胞已基本融解消散,而30 cm挫伤组则延迟至7 d;伤后13 d时,15 cm和30 cm挫伤组表现基本类似,但50 cm挫伤组则仍处于增生旺盛期。结论随着打击高度的增加,皮肤及肌肉同时出血的比例明显增加,挫伤后组织修复的炎症反应、增生反应表现逐渐加重,修复的过程也出现相应的延长。综合法医学实践应用以及本研究结果,推荐以50 cm高度所致挫伤(2.58 J/cm^2)作为今后挫伤损伤时间研究的实验动物参考模型。

Objective To explore the differences in the repair process of skin and skeletal muscle after contusion caused by blunt force attack with different heights. Methods Three degrees of contusion were performed on SD rats＇ right hind limbs by a designed free-dropping device falling from 15, 30 and 50 cm heights, which as a main consideration factor for degree of injury. The repair process of skin and skeletal muscle at 6 h, 24 h, 3 d, 7 d and 13 d after contusion were observed using routine histological methods.Results Hematoma within skin and/or muscle was found in the rats＇ hind limbs after contusion with three different heights. The repair processes were similar at 24 h after contusion. However, with the increase of height, the display degree was more obvious. At 3 d after contusion, the RBC of the hemorrhagic region would be decomposed and elapsed in 15 cm contusion group, but for 30 cm contusion group, it delayed to 7 d. At 13 d after contusion, the similar result was found in 15 cm and 30 cm contusion groups, in contrast, the 50 cm contusion group was still in the proliferative phase. Conclusion With the increase of height, the occurring rate of hematoma within skin and muscle at the same time increases, and the more serious histological appearance after contusion, including inflammation and proliferation, the longer healing process are observed. According to the results of present study and considering forensic application, the contusion model with 50 cm height（2.58 J/cm-2） is recommended as the experimental animal model for the future study of wound age estimation on contusion.