Predicting in vivo clinical performance of anterior cruciate ligament fixation methods from in vitro analysis: industrial tests of fatigue life and tolerance limits are more useful than other cyclic loading parameters.

Background: Anterior cruciate ligament graft fixations experience cyclic loads in vivo. Present cyclic loading studies testing fixation use "incremental cycling," "residual strength" protocols, or a combination. Industrial standards, however, rely on fatigue life testing and use tolerance limits to determine guaranteed minimum levels of cycles to failure.