Bony anatomy of coracoacromial arch: implications for arthroscopic portal placement in the shoulder.

Ease of access and occasional iatrogenic damage to the shoulder during arthroscopic procedures is dependent in part on bony landmarks that are not constant in their positions. Coracoacromial arch morphology of 280 scapulae was examined to study bony variations that influence portal placement posteriorly, superiorly, anteriorly, and laterally.