Reconstruction of the ACL remains one of the most challenging problem on orthopaedic knee surgery. Interference fit pull-out strength is dependent on bone quality, compression of the bone plug in osseous tunnel, length of the screwthread-bone contact,...
Reconstruction of the ACL remains one of the most challenging problem on orthopaedic knee surgery. Interference fit pull-out strength is dependent on bone quality, compression of the bone plug in osseous tunnel, length of the screwthread-bone contact, direction of the ligamentous force. Rigid fixation is probalby the most important in the success of procedures during the initial stages of healing.
The purpose of this study was to compare the maximum tensile strength, stiffness and linear load between 7mm x 20mm, 9mm x 20mm interference serew and trapezoid bone plug fixation methods with outside-in technique in femoral tunnel.
The results were as follows.
1) 7mm interference screw(N=15) pull-out tensile strength tests showed 805.35±54.61(N) maximum tensile strength, 83.33±10.98(N/mm)stiffness and linear load 685.99±86.32(N), respectively. The failure sites were all femoral tunnel area.
2) 9mm interference screw(n=10) pull-out tensile strength tests showed 886.91±46.16(N) maximum tensile strength, 69.20±6.61(N/mm)stiffness and linear load 740.93±103.10(N), respectively. The failure sites were all femoral tunnel area(N=9), except one case of midsubstance.
3) Trapezoid bone plug(N=10)pull-out tensile strength tests showed a maximum tensile strength 1046.30±32.90(N), stiffness 72.06±4.14(N/mm), and linear load 774.57±107.26(N), respectively, The failure sites were all femoral tunnel area(N=9) which were fracture and separation on the epiphyseal scar line, except one case of substance.
There was no significant difference between 7mm interference screw and 9mm interference screw but the trapezoid plug fixation shows significantly higher values than interference screw fixation in terms of maximum tensile strength, stiffness and linear load(P$lt;0.0001).