Is the Bare Spot reliable for the bone loss measurement?

Abstract

To evaluate the reliability of the Bare Spot (BS) as an anatomical landmark for the intra-operative definition of bone loss in anterior shoulder instability. The distances from the BS to the anterior (BS-A), posterior (BS-P) and inferior margins of the glenoid cavity were determined both under arthroscopic visualization and by an open approach in 20 shoulders. The BS did not coincide with the centre of the glenoid cavity of the studied shoulders because the BS-P distance was greater than the BS-A distance (p < 0.05) and was located 40% closer to the anterior margin. The authors suggest a correction factor: BP-A × 1.25/BP-P = 1. The BS is located at a mean distance of 40% of the joint diameter, relative to the anterior margin of the glenoid. This point may be used as a landmark, using a correction factor of its mostly anterior positioning. Arthroscopy was reliable for bone measurements of the shoulder joint.