This controlled cadaveric study tested whether plain radiographs and CT can accurately size an anteroinferior bony Bankart lesion. Defects of 0%, 9%, 21%, 34%, and 46% of glenoid length were created in 12 scapulae, then imaged with axillary, West Point, and CT views. The question: how does the known 21% critical defect actually appear on each imaging modality?
Itoi's earlier cadaveric work established that a glenoid defect of 21% or more of glenoid length fails after Bankart repair alone. This paper answers the next practical question: how do you actually see that critical defect on imaging?
The key mental model is magnification by slice choice. The same 21% defect looks like a trivial 20% shortening on the West Point view but a dramatic 50% loss at the inferior one-fourth CT slice. Use the West Point view as a screening tool, but do not be reassured by a defect that looks small. Add CT when the film is equivocal or the patient is too painful to position.
The practical decision rule from this work: at the inferior one-fourth CT slice, less than 20% apparent loss means repair alone, more than 50% means you need bone grafting. The 20% to 50% zone remains undefined and requires judgment.
This controlled cadaveric study tested whether plain radiographs and CT can accurately size an anteroinferior bony Bankart lesion. Defects of 0%, 9%, 21%, 34%, and 46% of glenoid length were created in 12 scapulae, then imaged with axillary, West Point, and CT views. The question: how does the known 21% critical defect actually appear on each imaging modality?
Itoi's earlier cadaveric work established that a glenoid defect of 21% or more of glenoid length fails after Bankart repair alone. This paper answers the next practical question: how do you actually see that critical defect on imaging?
The key mental model is magnification by slice choice. The same 21% defect looks like a trivial 20% shortening on the West Point view but a dramatic 50% loss at the inferior one-fourth CT slice. Use the West Point view as a screening tool, but do not be reassured by a defect that looks small. Add CT when the film is equivocal or the patient is too painful to position.
The practical decision rule from this work: at the inferior one-fourth CT slice, less than 20% apparent loss means repair alone, more than 50% means you need bone grafting. The 20% to 50% zone remains undefined and requires judgment.