小指指总伸肌腱的解剖学研究及其临床意义

The extensor digiti communis of little finger:applied anatomy and clinical application

目的:判定和证实小指指总伸肌腱(EDCs)的存在及出现率,预期重新评价对EDCs及腱结合的命名。方法:选用58侧成人防腐手与16侧新鲜手(左右各半),解剖观察第四掌骨背侧指总伸肌腱尺侧束的类型,测量了其伸向小指的腱性结构的倾斜度、长度和宽度;随机解剖了其中8侧前臂,观察EDCs的解剖学特点。结果:①按形态学特点将第四掌骨背侧指总伸肌腱尺侧束分为四大类型,即独立型12.2%(9/74)、分叉型包括“r”亚型48.6%(36/74)与”Y”亚型27.0%(20/74)、分离障碍型5.4%(4/74)和缺如型6.8%(5/74)。②按生物力学特点又将其分为四大类型,即:标准力线型44.6%(33/74)、小力线偏离型37.8%(28/74)、大力线偏离型10.8%(8/74)和缺如型6.8%(5/74)。③除缺如型外,第四掌骨背侧指总伸肌腱尺侧束的尺侧头均以腱束止于小指伸肌腱[93.2%(69/74)]。④小指的指总伸肌腱具有独立的肌腹和单独的神经支配[100%(8/8)]。结论:①第四掌骨背侧指总伸肌腱尺侧束的桡侧头是腱结合,其尺侧头是伸向小指的指总伸肌腱的延续;②EDCs与第四掌骨背侧指总伸肌腱尺侧束是同一解剖结构,其出现率为93.2%(69/74);③分叉型、分离障碍型和缺如型是小指指总伸肌腱解剖变异的不同形式。

Objoetive： To confirm the existance of EDCs and assess the definition of EDCs and juncuturae tendinum （JT）. Mothods：58 formaldehyde-fixed adult hands and 16 fi＇esh hands were dissected. The type, angle, length and width of ulnar slip of extensor over the fourth metacarpus （Us-EOFM） were observed. At the same time, 8 forearms were dissected randomly to observe the muscle belly and innervation of EDCs. Remits： 1. Us- EOFM can be classified morphologically into four types： independence type （12.2%）, bifurcation type with ＂r＂ subtype （48.6%） and ＂Y＂ subtype （27.0%）, inseparable type （5.4%） and absence type （6.8%）. 2. Us-EOFM can be classified biomechanically into four types： standard type （44.6%）, less deviation type （37.8%）, greater deviation type （10.8%） and absence type （6.8%）. 3. Besides absence type, the ulnar head of EOFM almost reaebed at extensor digiti minimi muscle tendon （93.2%）.4. EDCs had independent muscle belly and was innervated separately [100%（8/8）] .Conclusions： 1 .The radial head of Us-EOFM belongs to JT, and its ulnar head is the terminal structure of EDCs. 2. EDCs and Us-EOFM can be regarded as the same structure, and presented generally （93.2%）. 3. Inseparable type, bifurcation type and absence type are the variation of EDCs.