Abstract:

Objective　To explore anatomic features of the anterior humeral circumflex artery and axillary nerve, and provide clinic reference for processing safely the proximal humerus fracture.　Methods　 20 healthy adult upper limb specimens were used in this study. The distances from the anterior humeral circumflex artery and axillary nerve to the operative incision and the special bony landmarks were measured respectively.　Results　The vertical distance between the undersurface of the tip of acromion next to clavicle and the superior border of the anterior humeral circumflex artery was (5.1±0.2)cm (4.6~5.5 cm), and the distance between the prominence of small tuberosity and the superior border of anterior humeral circumflex artery (2.5±0.2)cm (2.0~3.0 cm). The internal diameter of anterior humeral circumflex artery was (2.6±0.2)mm (2.2~3.1 mm), and the obliquity of anterior humeral circumflex artery with the vertical axis of the humerus was （14±4）°(5~22°). The distance between the anterior-inferior border of acromion and the superior border of axillary nerve was (6.3±0.5)cm (5.2~7.0cm), and the distance between the prominence of greater tuberosity and the superior edge of axillary nerve (3.5±0.2)cm(3.2~4.1 cm). The obliquity of the the axillary nerve with the vertical axis of humerus was （22±7）°(8~37°). The transverse diameter of axillary nerve at the anterolateral 1/3 space of deltoid muscle was (4.2±0.8)mm(3.7~5.5mm), respectively.　Conclusions　The present study shows the safe area above the anterior humeral circumflex artery and the axillary nerve, with the incision and the bone landmarks. Using the safe area should avoid damaging the anterior humeral circumflex artery and the axillary nerve during the proximal humerus fracture operations.

Key words:  Proximal humerus, Safe zone, Applied anatomy, Clinical significance