Revising a loosened cancellous screw with a larger screw does not restore original pull-out strength - A biomechanical study.

Background: Cancellous screw fixation is often used in fracture fixation. When this screw is over-tightened, damage to the bone and other non-linear processes such as fracture and construct failure would be involved. The objectives of this study were (1) to determine the reduction in pull-out strength when a cancellous screw spins and (2) to determine how much pull-out strength can be restored by revising with a larger diameter screw.