Abe Y, Doi K, Katoh Y, Yamamoto H, Kataoka H, Kawai S
Department of Orthopedic Surgery, Yamaguchi University School of Medicine, Japan.
J Neurol Sci. 1996 Sep 1;140(1-2):61-6. doi: 10.1016/0022-510x(96)00111-6.
We studied peripheral nerve elongation of rabbit sciatic nerves. External fixators developed in our department were applied to 32 rabbit femurs in vivo. The rabbits underwent osteotomy of the femur and were divided into two groups subjected to different sciatic nerve elongation speeds: group I (0.45 mm/day) and group II (1.35 mm/day). The sciatic nerves were elongated 1.5, 3.0, 4.5, 6.0 and 7.0 cm by the external fixators, and the corresponding actual percentage of elongation of the nerves were 8, 16, 24, 30 and 40%. After elongation, nerve electrophysiology, nerve blood flow and pathology were studied. Forty percent elongation decreased nerve blood flow to 69 +/- 5.1% of contralateral controls in group I and to 20 +/- 4.8% in group II. Although no decrease in motor conduction velocity (MCV) was observed at any elongation distance, compound muscle action potential (CMAP) amplitude gradually decreased with increasing elongation. In group I, after 40% elongation, specimens showed the following pathologic changes: thinning of myelin sheath, atrophy and detachment of the axon from the myelin sheath. Furthermore, in group II, 40% elongation induced disorganization of the myelin sheath and Wallerian degeneration. Consequently 40% elongation was regarded as critical at speeds of both 0.45 and 1.35 mm/day.
我们研究了兔坐骨神经的周围神经延长情况。将我们科室研发的外固定器应用于32只兔的股骨进行体内实验。这些兔子接受了股骨截骨术，并被分为两组，分别以不同的坐骨神经延长速度进行实验：第一组（0.45毫米/天）和第二组（1.35毫米/天）。通过外固定器将坐骨神经延长1.5、3.0、4.5、6.0和7.0厘米，相应的神经实际延长百分比分别为8%、16%、24%、30%和40%。延长后，对神经电生理学、神经血流和病理学进行了研究。在第一组中，40%的延长使神经血流降至对侧对照的69±5.1%，在第二组中降至20±4.8%。尽管在任何延长距离下均未观察到运动传导速度（MCV）下降，但复合肌肉动作电位（CMAP）幅度随延长增加而逐渐降低。在第一组中，延长40%后，标本出现以下病理变化：髓鞘变薄、轴突萎缩并与髓鞘分离。此外，在第二组中，40%的延长导致髓鞘紊乱和华勒氏变性。因此，在0.45和1.35毫米/天的速度下，40%的延长均被视为临界值。
