Can the body slope of interference screw affect initial stability of reconstructed anterior cruciate ligament?: An in-vitro investigation

Abstract Background Superior biomechanical performance of tapered interference screws, compared with non-tapered reference to the anterior cruciate ligament (ACL) reconstruction process, has been reported in literature. However, effect screw’s body slope on initial stability ACL is poorly understood. Thus, main goal this study was investigate reconstructed ACL. Methods Based best screw-bone tunnel diameter ratios two different screws were designed and fabricated. The diameters both equal bone one-third their length from screw tip, then they gradually increased by 1mm, lower (LSTIS), 2 mm, higher (HSTIS) screws. To simulate reconstruction, sixteen soft tissue grafts fixed, using HSTIS LSTIS, synthetic blocks. Through applying sub-failure cyclic incremental tensile load, graft-bone-screw construct’s stiffness graft laxity each cycle, also through subsequent step loading failure, maximum load graft’s mode failure determined. Accordingly, fabricated other. Results provides a greater construct stiffness, laxity, LSTIS. Moreover, transverse rupture fibers for necking group major types grafts’ failure. Conclusions better replicates intact ACL’s behavior, causing less damage fibers; reducing laxity; increasing fixation stability. Nonetheless, finding optimal remains as an unknown can be subject future studies.