Initial Stability of Methods of Tibial Fixation in Anterior Cruciate Ligament Reconstruction

Song, Eun Kyoo; Lee, Young Keun; Kim, Byoung Soo; Shin, Sang Kyoo

Abstract

PURPOSE
To determine and to compare maximal tensile strength of different tibial fixation methods in ACL reconstruction.
MATERIALS AND METHODS
Biomechanical test using Instron machine(Model No.5569. Mass, U.S.A) was carried out to compare the pull out strength of six different tibial fixation techniques in 35 Yorkshire pig knees. The graft-bone complex was loaded and maximal tensile testing was performed. The preload of 30N was applied to the graft along the axis of the tunnel for 15 minutes. ANOVA and Duncan multiple comparison test was used for statistical analysis.
RESULTS
The mean maximal tensile strength of tibial fixation were 1254.5+/-55.8N in ACL preservation group, 625.1+/-116.7N in BPTB-Titanium interference screw group, 557.1+/-76.9N in BPTB-bioscrew group, 741.2+/-84.5N in hamstring-titanium interference screw group, 638.2+/-97.7N in hamstring-bioscrew group, 690.0+/-92.1N in hamstring-staple group, 268.8+/-26.3N in hamstring-tie over screw post group. The results of the experiment showed that the maximal tensile strength of various tibial fixation methods except tie-over screw post group were stronger than 454N of loading in normal activity.
CONCLUSION
We think cyclic loading test must be added and strong tibial fixation method compatible with normal strength of ACL should be developed in the future.