A Biomechanical Study of Graft Fixation in Posterior Cruciate Ligament Reconstruction

Jin, Hwan Ahn; Cho, Youn Jae; Kwon, Oh Soo; Kim, Kang Il

Abstract

Injuries of the posterior cruciate ligament have almost universally been treated nonoperatively in the past due to indignity of this complex structure. Recent studies have shown new informations on the anantomical, histological, biomechanical characteristics of the Posterior cruciate ligament PCL), and thereby interest of reconstruction surgery is increasing. But intraarticular PCL reconstruction still remains one of the most challenging problems in knee surgery. Although, various types of graft and surgical techniques have been used for reconstruction, results of surgery has been variable. In this study, three different methods of graft fixation for PCL reconstruction are evaluated biomechanically to determine the effect on mechanical property of reconstructed PCL using 30 porcine knees. Grafts used in this study were bone-patellar tendon-bone fixed with interference screw and Achilles tendon tied with suture. Additionally, five original PCLs were also tested by Instron universal testing instrument to determine its mechanical proprety. Tensile test was performed at extended knee position. It was demonstrated that mechanical strength of bone-patellar tendon-bone graft is superior to that of Achilles tendon graft. All of the failures of bone-patellar tendon-bone graft and Achilles tendon graft occurred at tibial fixation site whereas original PCLs which failed at proximal midsubstance of ligament. In conclusion, tensile strength of Bone-patellar tendon-bone graft used for PCL reconstruction is higher than that of Achilles tendon but latter can be used in terms of as clinical meanings.