Biomechanical Performance of Metallic and Bioabsorbable Interference Screw for Tibial Graft Fixation in ACL Reconstruction

Background: The interference screw is widely used to fix the graft in the tibial portion in anterior cruciate ligament (ACL) reconstruction. However, there is no evidence of what type of screws, if metallic or bioabsorbable, have the better mechanical performance. Methods: Twenty porcine tibias, 10 for metallic and 10 for bioabsorbable screw, were submitted to cyclic loading between 50 N to 250 N for 1000 cycles at 1 Hz. For devices that not failed during cyclic loading, a tensile test to failure was performed at strain rate of 50 mm/min. Results: There were no differences in the stiffness and ultimate failure load between metallic and bioabsorbable screw. Conclusion: There is no difference in biomechanical performance between metallic and bioabsorbable screw.