Anatomy, Biology and Biomechanics of Patellar Tendon Autograft Anterior Cruciate Ligament Reconstruction

Autologous bone-patellar tendon-bone autograft is a common choice for anterior cruciate ligament reconstruction and from both biologic and biomechanical perspectives is well-suited for this purpose. A centrally harvested, 10 mm wide patellar tendon graft has an estimated initial load-to-failure of 2977 N, and interference screw fixation of associated bone blocks provides initial pull-out strength as high as 640 N. After reconstruction, both intraarticular and extraarticular portions of the graft experience significant changes. The intraarticular portion of the graft undergoes a prolonged histologic, morphologic, and structural evolution known as ligamentization. The extraarticular portion of the graft becomes rapidly incorporated into surrounding bone tunnels over the weeks after implantation. The use of biologics to accelerate this process holds promise. This review summarizes relevant data regarding the anatomy, biology, and biomechanics of the anterior cruciate ligament, patellar tendon, and anterior cruciate ligament reconstruction with autogenous bone-patellar tendon-bone graft.