Glenoid Bare Area: Arthroscopic Characterization and Its Implications on Measurement of Bone Loss

PurposeThe purpose of this study was to characterize arthroscopically the frequency and location of the glenoid bare area.MethodsThree fellowship-trained orthopaedic sports surgeons evaluated and characterized the bare area of the glenoid in 52 consecutive patients undergoing arthroscopic surgery of the shoulder without a diagnosis of instability. Among the patients with a visible bare area, the position was measured, and when eccentrically located, an apparent bone loss or gain was calculated.ResultsThe bare area of the glenoid was observed in only 48% of patients undergoing arthroscopic surgery, and when observed, it was at the center only 37% of the time. Of the glenoids with visible bare areas, 8% were located anteriorly enough to result in an apparent bone loss calculation of greater than 20%. An additional 25% of visible bare areas were posteriorly located, resulting in an apparent bone gain.ConclusionsThe glenoid bare area is a variably visible and eccentric landmark on the glenoid and thus should not be used as the sole reference point to measure glenoid bone loss.Level of EvidenceLevel IV, retrospective observational study.