This anatomic study set out to find a consistent arthroscopic landmark for measuring glenoid bone loss in shoulder instability. The authors tested whether the glenoid bare spot sits at the center of the inferior glenoid in both living patients and cadavers. The goal was an objective way to decide when bone grafting is needed.
When you scope a recurrent anterior dislocator, you need an objective way to decide between a soft-tissue Bankart repair and adding bone. This paper gives you the tool: find the bare spot, measure to the posterior rim, then measure to the anterior rim. The posterior distance is half the intact diameter, so any shortfall on the anterior side is your compressive bone loss.
The reason this matters is that compressive loss cannot be measured directly. The crushed bone is gone, so you cannot just measure a fragment. The bare spot gives you a fixed center to work from. The number to remember is 25%. At roughly a quarter of the inferior glenoid diameter, the glenoid becomes an inverted pear, and arthroscopic Bankart repair alone fails 61% of the time in that setting.
Practically: an inverted-pear glenoid should push you toward a bone-restoring procedure rather than isolated soft-tissue repair.
This anatomic study set out to find a consistent arthroscopic landmark for measuring glenoid bone loss in shoulder instability. The authors tested whether the glenoid bare spot sits at the center of the inferior glenoid in both living patients and cadavers. The goal was an objective way to decide when bone grafting is needed.
When you scope a recurrent anterior dislocator, you need an objective way to decide between a soft-tissue Bankart repair and adding bone. This paper gives you the tool: find the bare spot, measure to the posterior rim, then measure to the anterior rim. The posterior distance is half the intact diameter, so any shortfall on the anterior side is your compressive bone loss.
The reason this matters is that compressive loss cannot be measured directly. The crushed bone is gone, so you cannot just measure a fragment. The bare spot gives you a fixed center to work from. The number to remember is 25%. At roughly a quarter of the inferior glenoid diameter, the glenoid becomes an inverted pear, and arthroscopic Bankart repair alone fails 61% of the time in that setting.
Practically: an inverted-pear glenoid should push you toward a bone-restoring procedure rather than isolated soft-tissue repair.