THE RELATIONSHIP OF THE AXILLARY NERVE TO ARTHROSCOPICALLY PLACED CAPSULOLABRAL SUTURES - AN ANATOMIC STUDY

Ten cadaveric shoulders (mean donor age, 60.5 years) underwent arthros copic placement of capsulolabral sutures as performed during arthrosco pic reconstruction for shoulder instability. In relation to the glenoi d face, the sutures were placed anterior, anteroinferior, inferior, po steroinferior, and posterior. All sutures entered the capsule approxim ately 1 cm away from the glenoid and exited beneath the labrum, and we re tied using arthroscopic knot-tying techniques. The shoulders were f rozen in the lateral arthroscopic position of approximately 45 degrees of abduction and 20 degrees of flexion and sectioned in the plane of the glenohumeral joint. The axillary nerve was then dissected, and the average distance from the nerve to each suture was found to be 16.7 m m at the anterior position, 12.5 mm at the anteroinferior position, 14 .4 mm at the inferior position, 24.1 mm at the posteroinferior positio n, and 32.3 mm at the posterior position. In no specimen was any sutur e closer to the axillary nerve than 7 mm. We noted a statistically sig nificant trend for the nerve to lie closest to the anteroinferior sutu re and gradually recede from the remaining sutures lying more posterio rly, This anatomic study is the first to demonstrate a relatively safe margin for arthroscopic suture placement between the capsule and axil lary nerve when these sutures are placed approximately 1 cm from the g lenoid rim.