Initial fixation strength of a new hybrid technique for femoral ACL graft fixation: the bone wedge technique.

摘要

BACKGROUND: Aperture fixation with interference screws matching the diameter of the tunnel is associated with the risk of graft laceration and graft rotation. HYPOTHESIS: A hybrid fixation technique (extracortical and aperture fixation) with undersized interference screw placed behind a bone wedge provides a higher fixation strength as aperture fixation with a screw alone matching the size of the tunnel. STUDY DESIGN: Experimental laboratory study. METHODS: We evaluated the initial fixation strength (single cycle and cyclic loading tests) of hybrid and interference screw aperture fixation using different sized interference screws in porcine knees. RESULTS: Analysis of yield load, maximum load and stiffness in the single cycle loading test showed no statistically significant differences for hybrid fixation with a 1 mm undersized screw and aperture fixation with a screw matching the size of the tunnel. The use of an undersized screw alone resulted in low fixation strength. CONCLUSION: The initial fixation strength of the hybrid technique with undersized screws is comparable to that of interference screw fixation matching the size. CLINICAL RELEVANCE: The new "bone wedge fixation" is an alternative for ACL graft fixation without the risk of graft laceration and graft rotation.