| Objectives To evaluate the biomechanical strength at the tibial site in anterior cruciate ligament(ACL) reconstruction with Cortical press-fit bolt.Methods 21 fresh frozen knee specimens were randomly divided into three groups:1.Cortical press-fit bolt(n=7);2.Bioabsorbable interference screw(n=7);3.Intrafix system (n=7).All specimens were rewarmed at room temperature(28℃) for 24 hours. An ACL reconstruction was performed on each specimens,using four-stranded hamstring tendon graft.At tibial site,every four-stranded hamstring tendon graft was fixed with Cortical press-fit bolt,Bioabsorbable interference screw or Intrafix system.On each sample,a load-to-failure test was performed.Ultimate failure load,stiffness,displacement of 100N,displacement of 400N,and mode of failure were recorded respectively.Results Test showed the average maximum load, 100N displacement,400N displacement and stiffness in Cortical press-fit bolt group were 512.19±36.13N,1.78±0.62mm,7.63±1.79mm,55.71±18.63 N/mm respectively.These statistics in Bioabsorbable interference screw group were 476.64±64.23N,1.34±0.54mm,7.57±4.31mm,63.98±31.00N/mm respectively. These statistics in Intrafix system group were 719.09±160.48N,1.02±0.32mm,4.73±1.99mm,96.77±36.85N/mm respectively.The maximum load and stiffness of Cortical press-fit bolt fixtion were lower than Intrafix fixtion(P<0.05); Displacement of 100N and 400N of Cortical press-fit bolt fixtion were higher than Intrafix fixtion(P<0.05);All the statistical datas have no statistical difference in Cortical press-fit bolt fixtion and Bioabsorbable interference screw fixtion(P>0.05).Conclusions The biomechanical strength at the tibial site fixation with Cortical press-fit bolt is similar to Bioabsorbable interference screw,and can meet physiological demand. |
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