Summary

A Biomechanical Study of Anterior cruciate ligament (ACL) Reconstruction with Biological Bone Press-fit Bolt

Abstract

The aim of this study was to evaluate the biomechanical performances
of allogenetic cortical bone press-fit bolt used as a clinical fixation

Method

in anterior cruciate ligament reconstruction based on
biomechanical tests in vitro.

Method

• Fresh deep frozen human allogenetic cortical bone was
machined into cortical bone press-fit bolt which is 6.0 mm
in diameter and 20.0 mm in length.
• The load-to-failure test and cycling test were carried out in
a goat model to reconstruct anterior cruciate ligament with
Achilles tendon autograft on the femoral and tibial side
fixed by 6.0 mm cortical bone press-fit bolt and 7 mm
absorbable screw（smith＆nephew）served as control.
• Maximum failure load, yield load, and stiffness of fixation in single
load-to-failure test were compared between the two groups.
• Cycle-specific displacement at cycles 1, 30, 100,500, and 1 000
were also compared in between
Result:On the femur and tibia side: the specific cyclic displacement of the bone
press-fit bolt group was less than that of the interface screw group (P <
0.05), which was similar to that of the normal ACL group (P > 0.05)
• On the tibia and femur side, the yield load(YL) and the maximum failure
load(MFL) of the biological bone press-fit bolt group were higher than that
of the interface screw group (P < 0.05).
• Tibial side fixation strength was greater (P < 0.05).

Discussion

＆ Conclusion
• The maximum failure load(MFL) of the biological bone press-fit bolt of
ACL reconstruction was great than 500N ,and the load displacement
after 50-250N,1000 times cyclic loading was about 5mm.
• The absorbable screw will take cutting injury of the graft ,which will be
harmful to fixed strength ,but our bone press-fit bolt will not.
• Allogenetic cortical bone press-fit bolt may be a good choice for ACL
reconstruction in the future.