Devkota P, Zeng Bing-fan, Tang Jian-fei, Fan Cun-yi
Department of Orthopaedic Surgery, Patan Hospital, Lalitpur, Lagankhel, Lalitpur, Nepal.
Kathmandu Univ Med J (KUMJ). 2005 Jul-Sep;3(3):281-4.
To analyze the influence of muscle tension in the histological changes of the skeletal muscle.
Fifty-four Sprague-Dawley (SD) rats were randomly divided into 3 groups. The left gastrocnemius muscles of the rats were dissected with only the neurovascular pedicles intact; the tibial nerves were cut and immediately repaired by epineurial suture. Then the Achilles tendons were isolated and treated accordingly; the Achilles tendon were lengthened by 0.5 cm in lengthened group, shortened by 0.5 cm in shortened group and left alone in normal (control) group. In the 2nd, 4th and 8th weeks after operation, the specimens were taken from gastrocnemius muscle for histological study by light and electron microscope.
In comparison between the groups, the gastrocnemius muscles in the shortened group showed less severe muscle atrophy and connective tissue proliferation, bigger diameter and cross section area of the muscle fibre than those in the normal and lengthened groups in all the postoperative periods.
A proper high tension of the muscle may decrease the muscle dystrophy and stops the histological changes of skeletal muscle by having much longer fibre length and bigger cross sectional area. Also increases the muscle function as the muscle active force-generating range is determined by muscle fibre length, while maximum muscle force is determined by physiologic cross-sectional area.
分析肌肉张力对骨骼肌组织学变化的影响。
将54只Sprague-Dawley（SD）大鼠随机分为3组。解剖大鼠左侧腓肠肌，仅保留神经血管蒂；切断胫神经并立即行神经外膜缝合修复。然后分离跟腱并进行相应处理；延长组将跟腱延长0.5 cm，缩短组将跟腱缩短0.5 cm，正常（对照）组不作处理。术后第2、4和8周，取腓肠肌标本，通过光镜和电镜进行组织学研究。
组间比较，在所有术后时期，缩短组的腓肠肌肌肉萎缩和结缔组织增生程度较轻，肌纤维直径和横截面积均大于正常组和延长组。
适当的高肌肉张力可减少肌肉营养不良，通过使肌纤维长度更长、横截面积更大来阻止骨骼肌的组织学变化。还可增强肌肉功能，因为肌肉的主动发力范围由肌纤维长度决定，而最大肌肉力量由生理横截面积决定。
