This two-part anatomic study asked how much anterior glenoid bone loss it takes to produce the arthroscopic inverted pear appearance in anterior shoulder instability. The authors measured bone loss arthroscopically in 53 instability patients and created inverted pear defects in 6 cadaveric glenoids to define the threshold.
When you view the glenoid en face from the anterosuperior portal and the inferior half narrows to a sharp apex, you are looking at least 25% to 27% bone loss in the face.
That single visual cue matters because a Bankart repair only fixes soft tissue. It cannot rebuild the missing bony arc, which is why arthroscopic repair with an inverted pear failed 61% of the time in the authors' prior series versus 4% without significant bone loss.
Use the bare spot as your reference: it sits at the geometric center of the inferior glenoid, so distance from bare spot to posterior rim minus bare spot to anterior rim gives you bone loss in millimeters. This lets you quantify loss even without CT.
When you see an inverted pear, plan for a bone-restoring procedure such as Latarjet rather than isolated Bankart repair. The exact 25% to 30% threshold and the choice of glenoid augmentation remain actively debated in the instability literature.
This two-part anatomic study asked how much anterior glenoid bone loss it takes to produce the arthroscopic inverted pear appearance in anterior shoulder instability. The authors measured bone loss arthroscopically in 53 instability patients and created inverted pear defects in 6 cadaveric glenoids to define the threshold.
When you view the glenoid en face from the anterosuperior portal and the inferior half narrows to a sharp apex, you are looking at least 25% to 27% bone loss in the face.
That single visual cue matters because a Bankart repair only fixes soft tissue. It cannot rebuild the missing bony arc, which is why arthroscopic repair with an inverted pear failed 61% of the time in the authors' prior series versus 4% without significant bone loss.
Use the bare spot as your reference: it sits at the geometric center of the inferior glenoid, so distance from bare spot to posterior rim minus bare spot to anterior rim gives you bone loss in millimeters. This lets you quantify loss even without CT.
When you see an inverted pear, plan for a bone-restoring procedure such as Latarjet rather than isolated Bankart repair. The exact 25% to 30% threshold and the choice of glenoid augmentation remain actively debated in the instability literature.