Cheung Sunny, Fitzpatrick Michael, Lee Thay Q
Orthopaedic Biomechanics Laboratory, VA Long Beach Healthcare System and University of California, Irvine, CA, USA.
J Shoulder Elbow Surg. 2009 Sep-Oct;18(5):748-55. doi: 10.1016/j.jse.2008.12.001. Epub 2009 Mar 17.
The axillary nerve may be injured during percutaneous fixation of proximal humerus fractures. This study investigated the kinematic behavior of the superior and inferior borders of the axillary nerve under varying shoulder positions. This information may reduce iatrogenic neurologic injury during fracture reduction and hardware placement.
The lateral deltoid approach was performed on 7 fresh frozen shoulders. The inferior and superior borders of the axillary nerve were tagged. Screws were placed in the anterior, middle, and posterior acromion as landmarks. Three-dimensional distances of the inferior and superior border of the nerve were measured to the mid-acromion while the shoulder was placed in combinations of forward flexion, vertical abduction, and humeral rotation. The distances were compared by repeated measures ANOVA statistical analysis.
The distance from the mid-acromion to the superior border of the axillary nerve was 66.6 mm (+/-5.7), and to the inferior axillary nerve was 75.7 mm (+/-5.8) with the shoulder in neutral position. Vertical abduction to 60 degrees significantly moved the superior and inferior borders of the axillary nerve to a distance of 53.9 (+/-7.7) and 61.6 mm (+/-8.1), respectively (P < 0.005). Forward flexion had no significant effect on the position of the axillary nerve (P > 0.5). The longest distance from the mid-acromion to the inferior border of the axillary nerve was 86 mm with the arm forward flexed.
The main determinant of axillary nerve position with respect to the acromion is vertical abduction. Axillary nerve position is essentially unaffected by varying degrees of humeral rotation and forward flexion. Vertical glenohumeral abduction to 60 degrees is required to move the nerve significantly closer to the acromion.
在肱骨近端骨折的经皮固定过程中,腋神经可能会受到损伤。本研究调查了在不同肩部位置时腋神经上下边界的运动学行为。这些信息可能会减少骨折复位和置入内固定物过程中的医源性神经损伤。
对7个新鲜冷冻的肩部进行三角肌外侧入路。标记腋神经的下边界和上边界。将螺钉置入肩峰的前、中、后部作为标志点。当肩部处于前屈、垂直外展和肱骨旋转的组合位置时,测量神经下边界和上边界到肩峰中点的三维距离。通过重复测量方差分析统计分析比较这些距离。
肩部处于中立位时,从肩峰中点到腋神经上边界的距离为66.6毫米(±5.7),到腋神经下边界的距离为75.7毫米(±5.8)。垂直外展至60度时,腋神经的上边界和下边界分别显著移动至距离53.9(±7.7)和61.6毫米(±8.1)处(P<0.005)。前屈对腋神经的位置没有显著影响(P>0.5)。手臂前屈时,从肩峰中点到腋神经下边界的最长距离为86毫米。
腋神经相对于肩峰位置的主要决定因素是垂直外展。腋神经的位置基本上不受肱骨不同程度旋转和前屈的影响。需要将肱骨头垂直外展至60度才能使神经明显更靠近肩峰。