This study built virtual 3D CT reconstructions of 13 fractured pelves to measure the true intraosseous corridor for percutaneous acetabular screws. It asked whether cross-sectional column diameter can predict the largest screw that safely stays within bone.
When you plan a percutaneous anterior column screw, do not trust the wide bony diameter you see on a single CT slice. The corridor is curved and narrow, so the anterior column only accepts about a 6.4 mm screw. This is why the paper supports Routt's rule of using 3.5 to 4.5 mm screws in the anterior column.
The mismatch is dramatic: a column measuring nearly 20 mm in cross-section tolerates a screw a third that size, because safe diameter is set by the tightest point along the whole path. The posterior column is more forgiving at roughly 11 mm, but still far below its cross-sectional width.
The practical message: use full 3D reconstruction, not slice measurements, and reserve the largest screws for corridors you have verified in three dimensions.
This study built virtual 3D CT reconstructions of 13 fractured pelves to measure the true intraosseous corridor for percutaneous acetabular screws. It asked whether cross-sectional column diameter can predict the largest screw that safely stays within bone.
When you plan a percutaneous anterior column screw, do not trust the wide bony diameter you see on a single CT slice. The corridor is curved and narrow, so the anterior column only accepts about a 6.4 mm screw. This is why the paper supports Routt's rule of using 3.5 to 4.5 mm screws in the anterior column.
The mismatch is dramatic: a column measuring nearly 20 mm in cross-section tolerates a screw a third that size, because safe diameter is set by the tightest point along the whole path. The posterior column is more forgiving at roughly 11 mm, but still far below its cross-sectional width.
The practical message: use full 3D reconstruction, not slice measurements, and reserve the largest screws for corridors you have verified in three dimensions.