Os Subscapularis vs Old Lesser Tuberosity Avulsion It appears that this is more likely to represent an Os Subscapularis than a chronic avulsion fracture non-union of the lesser tuberosity. It seems the ossicle is larger than the normal lesser tuberosity, and the subscapularis tendon appears normal. Cyst-like changes deep to the synchondrosis suggest chronic micromotion. Have any of you seen an Os Subscapularis? Does it exist? I could find no reference. BTW the supra and infra are normal, but there is glenohumeral DJD.