The position of the upper limb during shoulder arthroscopy does not affect the distance between axillary nerve and glenoid.

PURPOSE: The segment of the axillary nerve (AxN) near the glenoid rim is at risk of iatrogenic lesion during arthroscopic procedures. We hypothesize that the distance between the AxN and the glenoid rim is not modified by the patient's positioning. The primary objective was to compare the position of the AxN with the inferior glenoid rim in lateral decubitus or in beach chair and positions of the upper limb. METHODS: Sixteen shoulders were dissected in beach chair position with the shoulder in neutral rotation. Needle one was placed in the axillary nerve where it was the closest with the inferior glenoid rim. In lateral decubitus with traction and 70° of abduction needle two was placed in the AxN at the closest with the inferior glenoid rim. The glenoid rim was marked with a needle at 6 o'clock. In beach chair position, the distance between needle one and the glenoid needle was measured for six positions. In lateral decubitus, measures were done for two positions of abduction. In lateral decubitus with 70° of abduction, the distance between needle two and the glenoid needle was also measured. RESULTS: The mean distance between AxN and the inferior glenoid rim was 14.4 mm in reference position in beach chair. The results showed the absence of difference between the positions during surgery except for lateral decubitus with 70° of abduction. CONCLUSION: Our study showed that the position of the shoulder during arthroscopic procedures cannot take away the AxN from the inferior glenoid rim. LEVEL OF EVIDENCE: Level IV-basic science study.