Bare Area of the Glenoid: Magnetic Resonance Appearance with Arthroscopic Correlation

Objective: To review the radiologic findings of a rarely reported focal area of acquired cartilage thinning located at the center of the glenoid fossa. Methods: We retrospectively reviewed the medical records of 3 patients, each possessing a bare area of the glenoid detected on magnetic resonance (MR) imaging. A literature search was performed to obtain the most current information regarding this uncommon entity. Results: Magnetic resonance imaging of the glenoid demonstrated a smoothly marginated subcentimeter area of thinning of the central articular cartilage containing hyperintense joint fluid or contrast in the case with MR arthrography. Arthroscopic correlation was obtained in a single case. Conclusions: The bare area of the glenoid is an acquired cartilage defect located at the center of the glenoid articular surface. Characteristic findings can be seen on MR imaging. Care should be taken not to mistake this acquired condition for posttraumatic defects of the glenoid articular cartilage.