Samart Supawat, Apivatgaroon Adinun, Lakchayapakorn Kajorn, Chemchujit Bancha
J Med Assoc Thai. 2014 Aug;97 Suppl 8:S27-33.
Deltoid splitting is one of common and useful approaches in proximal humerus surgery. The disadvantage of this approach is high risk of axillary nerve injury. Nowadays, there is no consensus in the proper mean of the individual's axillary nerve location.
The present study aim to determine the correlation between the axillary nerve and the upper arm length that may create equations to calculate the nerve location.
Seventy shoulders were measured the distance from lateral acromial edge to axillary nerve and compared with upper arm length in three positions of the shoulder (adduction 30°, abduction 45° and 90°). The authors used distance of lateral acromial edge to lateral epicondyle and tip ofgreater tuberosity to lateral epicondyle as the upper arm length.
The average distance ofshoulder adduction 30°, abduction 45° and90° were 57.9, 57.1 and 52.9 mm, respectively. All of three positions showed linear correlation to upper arm length from both of reference sites. From acromion edge reference, where "Y" is axillary nerve distance in mm and "x" is upper arm length in cm, the relation were Y= 2.3x-10, Y= 2x-2 and Y= 2x-7with the accuracy rate were 88.57%, 85.71% and 81.43%, respectively. From greater tuberosity reference, the relations were Y = 2.54x-14, Y = 2x and Y = 2.3x-12 with the accuracy rates 87.14%, 80% and 84.29%, respectively.
There is linear correlation between distance from the lateral acromial edge to axillary nerve and the upper arm length. The authors can predict the danger zone in the location of the anterior upper branch of the axillary nerve. However, further clinical study may helpful to prove the equations. Level ofevidence: Basic science anatomy study.
三角肌劈开是肱骨近端手术中常用且有效的方法之一。该方法的缺点是腋神经损伤风险高。目前，对于个体腋神经位置的合适测量方法尚无共识。
本研究旨在确定腋神经与上臂长度之间的相关性，以便建立计算神经位置的公式。
测量70例肩部从肩峰外侧缘到腋神经的距离，并在肩部三个位置（内收30°、外展45°和90°）与上臂长度进行比较。作者使用肩峰外侧缘到肱骨外上髁的距离以及大结节尖端到肱骨外上髁的距离作为上臂长度。
肩部内收30°、外展45°和90°时的平均距离分别为57.9、57.1和52.9毫米。三个位置与两个参考点的上臂长度均呈线性相关。以肩峰边缘为参考点，“Y”为腋神经距离（单位：毫米），“x”为上臂长度（单位：厘米），关系式分别为Y = 2.3x - 10、Y = 2x - 2和Y = 2x - 7，准确率分别为88.57%、85.71%和81.43%。以大结节为参考点，关系式分别为Y = 2.54x - 14、Y = 2x和Y = 2.3x - 12，准确率分别为87.14%、80%和84.29%。
从肩峰外侧缘到腋神经的距离与上臂长度之间存在线性相关性。作者可以预测腋神经前上支位置的危险区域。然而，进一步的临床研究可能有助于验证这些公式。证据水平：基础科学解剖学研究。
