模拟肩峰下前外侧扩展入路肱骨近端骨折复位内固定的解剖学特点

Surgical anatomy of extended anterolateral acromial approach for internal fixation of proximal humeral fracturesm

背景:临床用于肱骨近端骨折的常用入路主要有两种:前内侧入路、肩峰下前外侧入路,然而现有的手术入路存在一定局限性。目的:分析臂部前外侧腋神经与肱骨上段及三角肌前、中亚部的解剖关系,为复位内固定治疗肱骨近端骨折寻找新入路提供解剖学依据。方法:解剖12具成人(男7例,女5例)防腐上肢标本20侧,了解腋神经前支在三角肌前、外亚部中的走行,比较经过两亚部时跨越肌缝的神经分支形态。完成初步数据收集后,进行尸体上模拟复位内固定实验。结果与结论:腋神经前支横向行走于三角肌肌腹深面中上1/3水平,距离肩峰外下缘(6.0±1.3)cm,前亚部仅有1支一级神经支支配,两亚部间为一连续的乏血管横越的肌缝,肌缝位于肩峰前角向下的延长线处,肉眼观为一白色结缔组织条带,腋神经通过肌缝时无分支,游离后跨缝段长度均大于1cm,放置钢板后腋神经张力不高。通过肩峰下三角肌前、中亚部肌缝入路,显露腋神经支配前亚部的一级神经支并进行分离保护后,可以向下延伸切口,能够安全地暴露上段肱骨,在直视下进行骨折复位和金属植入物内固定等操作。

BACKGROUND：There are many surgical approaches for the shoulder joint.Two of which are widely used for proximal humeral fractures in clinic：the deltopectoral approach and the anterolateral acromia approach.However,the existing surgical approaches have some limitations.OBJECTIVE：To observe the courses of the axillary nerve and relative structures of humerus and deltoid from lateral arm,and to provide the anatomical information of a new surgical approach for proximal humeral fracture.METHODS：Twelve adult cadaveric upper limbs（male 7,female 5） were dissected to define the course of the anterior branch of axillary nerve in the anterior and middle compartments of deltoid muscle,measure the relative distance of them,compare the characteristics of the axillary nerve as it crosses the raphe between the middle and anterior heads of the deltoid.Simulation of surgical operation was implemented on a corpse after the initial data collection had been conducted.RESULTS AND CONCLUSION：The anterior branch of axillary nerve passed through the upper 1/3 of the deltoid muscle,the crossing of the anterior branch of axillary nerve and the line from the lateral tip of acromion to deltoidtuberosity was（6.0±1.3） cm below the level of acromon.A single motor branch was found to distribute the anterior head of the deltoid.An avascular raphe was located between the anterior and middle heads of the deltoid.The raphe could be identified as a white band of connective tissue between the two muscular heads.No branches to the anterior head of the deltoid cross the raphe was found.The cross stitch length in this group were greater than 1 cm,the tension of the axillary nerve was low after the plate was implanted.Through the raphe between the two muscular heads of deltoid,a surgical approach could be created for the exposure of proximal humerus,with easily extending distally after protecting the main motor branch of the axillary.This surgical approach is safe for fracture reduction directly,with subsequent plate fixation.