砧镫关节、镫骨及相邻面神经解剖对镫骨手术的意义

Anatomy of Incudostapedial Joint, Stapes and Facial Nerve in Stapes Surgery

目的通过测量镫骨手术中常用的解剖数据和分析相邻结构间的关系,为耳硬化症的镫骨手术提供解剖学数据。方法测量10例颞骨的砧镫关节角度、砧骨长突下缘距离镫骨足板中央的垂直距离及镫骨足板的厚度,观察面神经管同前庭窗的关系。结果发现砧镫关节的夹角为86.5±8.6°,砧骨长突下缘距离镫骨足板中央的距离为3.58±0.35 mm,足板厚度为0.31±0.03 mm。前庭窗完全显露率为90%,面神经遮住前庭窗一半者占10%。结论正常砧镫关节角度并非绝对为90°;将砧骨长突下缘至镫骨足板中央的垂直距离、镫骨足板的厚度以及人工镫骨活塞深入足板内侧面下方的0.5 mm 3个值相加为人工镫骨的长度。面神经低位的病例可能会影响活塞的置入。

Purpose To provide anatomic date for the stapes operation of otosclerosis by means of measuring the common anatomic data and analysizing the relationship between the adjacent structures in the stapes surgery. Methods The angle of incudostapedial joint, the vertical distance of the long process of incus to the stapes footplate and the thickness of the stapes were measured. The relation of the fallopian aqueduct and the oval windows were observed. Results The angle of incudostapedial joint is 86.5± 8.6°, tlie distance of the long process of incus to the stapes footplate is 3.58± 0.35 mm, and the thickness of the stapes is 0.31 ±0.03 mm. 90% of oval windows were totally exposed, and 10% were half covered with facial nerve. Conclusion The normal angle of incudostapedial joint is not absolutely 90°. The length of stapes prosthesis equals to distance of the long process of incus to the stapes footplate plus the thickness of the stapes plus 0.5 mm. The low positioned facial nerve may impede the placement of the pison.