ACL prosthesis: any promise for the future?

Biological tissue autograft reconstruction using the patellar tendon or quadrupled semitendinosus/gracilis tendons has become the most popular procedure in surgical treatment of a ruptured anterior cruciate ligament (ACL). This article provides a review of the history of the use of prosthetics with respect to ACL reconstruction grafts including Carbon Fibre, Gore-Tex and Dacron prosthetics, as well as the Leeds-Keio Artificial Ligament and the Kennedy Ligament Augmentation Device (LAD). Emphasis is placed on the ligament advanced reinforcement system (LARS) as preliminary investigations of its use have been encouraging. Significant progress has been made recently with respect to the understanding of ACL anatomy, composition, biomechanics, and healing processes, leading to innovative techniques using approaches based in tissue engineering principles. Most of grafts that have been developed to date have failed due to unsatisfactory long-term physiological and functional performance. Most permanent ACL prostheses are prone to creep, fatigue, and mechanical failure within several years after implantation. In view of these factors, prosthetics are not widely used today in ACL reconstruction, and autogenous tissue grafts remain the gold standard used by the majority of surgeons. Perhaps development of resorbable, tissue inducing and cell-seeded biomaterials will improve the long-term biomechanical performance of the reconstructed ACL. Tissue ingrowth scaffolds and ligament augmentation devices require further refinement to provide effective mechanical support while avoiding stress shielding of the host tissue. While research into improved ACL treatment options continues, the synthesis of recent advancements provides some new optimism towards the regeneration of an ACL mirroring its original stability, function, and longevity.