An analysis of EndoButton displacement and attitude in anterior cruciate ligament reconstruction using bone tunnel axis

EndoButton is a fixation device which is attached to an end point of the bone tunnel in the anterior cruciate ligament (ACL) reconstruction. Displacement of the EndoButton affects the clinical outcome. Analysis of the EndoButton displacement can support to avoid the misplacement. This study set the goal to propose an analysis of EndoButton attitude after anterior cruciate ligament reconstruction (ACL) in knee CT image. In the experiments, the proposed method was applied to 15 EndoButtons with the single and double bundle techniques of ACL reconstruction. The result shows a correlation between displacement length and attitude of EndoButton (r = −0.727, N = 9, p = 0.027 < 0.05). This study has concluded that the proposed method can quantitatively analyze the EndoButton attitude from the CT image after the ACL reconstruction and the EndoButton might displace relative to the attitude between time-zero and follow-up.