The glenoid bare spot, or glenoid bare area, is a small central or slightly eccentric area of the inferior glenoid fossa, where the articular cartilage is markedly thinner or completely absent 2. It is considered to be a normal aging-related phenomenon 1.
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Epidemiology
The glenoid bare spot can be found in as much as 80-88% of adult cadavers 1,3. It is rarely observed in children <10 years 4,5 and not in fetuses 8. Its incidence seems to increase with age.
Pathology
The etiology of the bare area is not fully understood - it was previously speculated that it is an acquired lesion due to repetitive stress 2,4,8. Recently, a developmental origin associated with the fusion of glenoid ossification centers has been proposed 5.
Radiographic features
It is a small (2-12mm of range), roughly round area of thinned cartilage located in the very center of the inferior glenoid fossa 4,7 or slightly anterior to it 3,6. It is best appreciated using fluid-sensitive sequences like T2 FSE in coronal and axial planes.
It should not be accompanied by any pathologic changes of the underlying bony glenoid.
It is considered to be a normal aging-related phenomenon and should not be mistaken for cartilage ulceration or osteochondral defect.
See also
Tubercle of Assaki is a similar phenomenon found in the same location as the bare spot.