臀三角的应用解剖
【摘要】 目的确定臀三角内梨状肌上、下孔和坐骨神经的体表定位，为临床应用提供解剖学资料。方法解剖观察30侧成人臀区标本。以同侧股骨大转子外侧缘最突出点(A)、坐骨结节(B)、髂后上棘(C)三点，形成的三角形区域称为臀三角。观测臀三角内梨状肌、坐骨神经、梨状肌上、下孔以及穿梨状肌上、下孔的血管神经与臀三角的位置关系。结果臀三角各边的长度分别为：髂后上棘转子间距，男(15.2±1.35) cm，女(11.5±0.72) cm；髂后上棘结节间距，男(13.3±0.87) cm，女(10.3±0.49) cm；转子结节间距，男(8.3±0.83) cm，女(5.5±0.61) cm。臀上动脉、静脉、神经出入梨状肌上孔的体表投影在髂后上棘与大转子连线中、上2/5交界处向下0～6.8 mm内；臀下动脉、静脉、神经出入梨状肌下孔处的体表投影在髂后上棘与坐骨结节连线中、下2/5处；坐骨神经出梨状肌下孔处的体表投影在坐骨结节与大转子连线中外3/5处。结论臀三角的相关数据对临床应用具有一定的参考价值。
Applied anatomy of anal triangle。
Abstract: Objective To determine surface projection of suprapitiform foramen, infrapiriform foramen and sciatic nerve in anal triangle, so as to provide anatomical data for the clinical application. Methods Thirty dead adult haunchs were dissected and measured. The anal triangle was made up of the ischial tuberosity, the posterior superior iliac spine and the most prominent point at the lateral border of greater trochanter of femur, the position relation between anal triangle and piriformis, sciatic nerve and blood vessel permeating suprapitiform foramen and infrapiriform foramen were measured. Results The length between posterior superior iliac spine and greater trochanter of femur was (15.2±1.35) cm for man and (11.5±0.72) cm for woman; the length between posterior superior iliac spine and ischial tuberosity was (13.3±0.87) cm in man and (10.3±0.49) cm in woman; the length between greater trochanter of femur and ischial tuberosity was (8.3±0.83) cm in man and (5.5±0.61) cm in woman; the surface projection where the superior gluteal artery, superior gluteal veins and superior gluteal nerve permeate the suprapitiform foramen was below the point 0～6.8 mm between 2/5 superior and middle trunk from posterior superior iliac spine to greater trochanter of femur; the surface projection where the inferior gluteal artery, inferior gluteal veins and inferior gluteal nerve permeate the infrapiriform foramen was at the point between 2/5 inferior and middle trunk from posterior superior iliac spine to ischial tuberosity; the surface projection where sciatic nerve permeate the infrapiriform foramen was at the point between 3/5 lateral and middle trunk from ischial tuberosity to greater trochanter of femur. Conclusion The data about anal triangle can provide anatomical reference for the clinical application.
Keywords: anal triangle; piriformis; sciatic nerve; applied anatomy。
臀区解剖结构复杂，神经血管以梨状肌上、下孔为中心紧密排列。这一区域的应用解剖研究，对神经阻滞麻醉、坐骨神经痛、梨状肌综合征及髋关节疾病的诊断和治疗具有重要的临床意义。本文以坐骨结节、髂后上棘和股骨大转子外侧缘最突出点三点连线为臀三角，测量梨状肌、坐骨神经、梨状肌上、下孔以及穿经梨状肌上、下孔的血管神经与臀三角的位置关系，为临床提供解剖学资料。
1 材料与方法。
采用常规防腐固定的成人尸体标本38侧（男23侧，女15侧），按层次解剖臀部，暴露梨状肌。选直立位时股骨大转子外侧缘最突出点为A点，坐骨结节为B点，髂后上棘为C点，将该三点的连线称为臀三角。从梨状肌上孔血管神经束出孔处向AC作垂线交AC于D点，BC交梨状肌下孔于E点，坐骨神经外侧缘交AB于F点(图1)。用游标卡尺分别测量：①AB、AC和BC的长度。②AF、BE、CD和梨状肌上孔到D点的距离，并换算成CD/AC、BE/BC和AF/AB的相对比值。对所得数据运用SPSS软件进行统计学处理及分析。
A:股骨大转子外侧最突出点; B:坐骨结节; C:髂后上棘; D:梨状肌上孔向AC线作垂线与AC线的交点; E:梨状肌下孔与BC线的交点; F:坐骨神经外侧缘与AB线的交点。
2结果。
2.1臀三角层次结构。
臀三角区的结构除皮肤及浅筋膜外共分为四层：第一层为臀大肌和皮神经；第二层为臀中肌和梨状肌；第三层为血管神经束，主要有臀上、下血管和臀上、下神经、阴部内动、静脉和阴部神经以及坐骨神经；第四层为臀小肌、上孖肌、闭孔内肌腱、下孖肌及股方肌（图2）。梨状肌上孔在臀三角内者29例，约占76.3%。AC线经过梨状肌上孔者9例，占23.7%。坐骨神经在梨状肌下孔处分为腓总神经和胫神经者4例，占10.5%。腓总神经穿梨状肌上孔，胫神经穿梨状肌下孔者1例，占2.6%。经梨状肌上孔出入盆的有臀上血管神经束；经梨状肌下孔出入盆的由内至外有阴部内血管神经束、臀下血管神经束、股后皮神经和坐骨神经，其中阴部内血管神经束经坐骨小孔进入坐骨直肠窝。