大鼠尺神经的损伤修复对其支配的爪内骨骼肌形态学改变的影响

目的通过对大鼠尺神经不同损伤断面和不同修复时间的实验研究．观察其支配的爪内骨骼肌形态学的改变,探讨法医临床学对尺神经损伤鉴定的最佳时机。方法选用SD大鼠42只．建立尺神经损伤修复模型,取爪内骨骼肌称量湿重,经HE和Masson染色,测量肌肉湿重、肌细胞横截面积和胶原纤维占肌纤维截面积的比率。结果（1）尺神经损伤后早期修复组的爪内骨骼肌萎缩程度均低于实验对照组．且即刻修复组比1个月修复组爪内骨骼肌功能恢复效果好。（2）失尺神经支配后爪内骨骼肌中的胶原纤维逐渐增多。（3）腕部与肘部尺神经损伤后,在相同时间修复尺神经,爪内骨骼肌萎缩的变化规律一致。结论尺神经损伤即刻修复能完全恢复爪内骨骼肌形态学改变,1个月修复能部分恢复其形态学改变．3个月修复则无法恢复其形态学改变;爪内骨骼肌中胶原纤维的增多是影响手术疗效和功能恢复的可能性原因之一;腕部与肘部的尺神经损伤修复对爪内骨骼肌形态学改变的影响无明显差异。

Repaired ulnar nerve and effect on its innervating muscles in rat

Objective To study the morphological changes of the rat claw inner skeletal muscle after ulnar nerve injury at different sections and different recovery times. Methods Forty-two adult male Sprague-Dawley rats were selected and placed randomly in seven groups. After establishing model of injury and repair of claw inner skeletal muscle by cutting off the ulnar nerve, the muscle wet weight, cross section area of myocytes, and collagen fibers were measured. Results Claw inner skeletal muscle atrophy was significantly less in experiment groups compared with the control groups after ulnar nerve injuries. The functional recovery was better in the early repair groups than the late repair group. Collagen fibers increased slowly in earlier stage, but more significantly in late stage. The muscle atrophy was similar in wrist and elbow after ulnar nerve injury during the same recovery period. Conclusion The function can recover completely or partly in early repair groups, but not quite effective in late stage. The increase of collagen fiber is one of the reasons to undermine the recovery effect of damaged ulnar nerve. There is no obvious difference of effect on the morphological changes of the rat claw inner skeletal muscle no matter the ulnar nerve is injured at wrist or elbow.