Histological characteristics of the rabbit patellar ligaments repaired after blast injury and seawater immersion / 中华创伤骨科杂志

ABSTRACT

Objective To observe the histological characteristics of the rabbit patellar ligaments repaired after blast injury and seawater immersion. Methods Explosive wounds were made at the knee joints of 36 New Zealand white rabbits with a 0.9 g detonator fastened on the anterolateral side of the joint. Then the wounds were immersed in seawater for 1 hour. After debridement and anti-inflammatory treatment, the broken patellar ligaments were sutured at the 4th day (n=19) and the 6th day (n=1) respectively. Histological examinations and electronic microscope observations of the injured and ruptured patellar ligaments were done respectively soon after blast injury, 1 hour after seawater immersion, 1 month, 2 months and 3 months after repair. Results The distortion and contracture of the ligament fibers were shown in the explosive injury group (n=14). The ligament fibers were broken and the fibroblasts were stacked in disorder in the rupture group (n=22). In the 2 groups, the ligament samples contained mainly collagen Ⅰ. The edema of tissue appeared after seawater immersion for 1 hour and the majority elements were collagen Ⅲ. 3 months after repair, the ligaments in the explosive injury group recovered almost to normal while in the rupture group the fiber arrangement was not compact and the fibroblasts were obviously fewer than those in the explosive injury group. Conclusions After explosive injury and seawater immersion, the rabbit patellar ligaments mainly excrete collagen Ⅲ. 3 months is enough for ligaments to repair the explosive injury. Even after treatment and 3 months’repair, there is still a distinct difference between the formerly ruptured ligaments and the normal tissue.