Interference with the rotator cuff footprint
The entry point for a bent nail may go through the bony attachment of the rotator cuff. This bony defect in the footprint cannot be reconstructed later.
The entry point for a straight nail lies under the rotator cuff so the nail is inserted through the rotator cuff. This requires an incision, which should be made in the line of the tendon fibers which can then be closed effectively by a side to side suture.