Future perspectives in synthetic grafts used in anterior cruciate ligament reconstruction

It is already known that the lesion of the Anterior Cruciate Ligament (ACL) is one of the most frequent knee pathologies, especially in professional sportsmen, but also for the active average-aged population. ACL surgical reconstruction is one of the most documented and common intervention in sport traumatology. The consequence of an ACL lesion is the appearance of anterior-posterior laxity, which leads to an unstable knee predisposed to the appearance of associated lesions and a much faster development of a degenerative disease. That is why in complete lesions of the ACL, the chosen therapeutic attitude is the surgical reconstruction using biological grafts (autograft or allograft) or artificial grafts made from different materials. The limits imposed by autografts and allografts in ACL reconstruction together with the scientific progress made in materials science and biology have conducted a lot of interest for developing systems and materials for anterior cruciate ligament replacement or reconstruction. This review has the purpose to synthesize the important steps taken in the development of polymer-based materials for ACL, their advantages and disadvantages and the results of different in vitro and in vivo tests. Until now, there is none successfully polymer system for ligament reconstruction implanted in humans. The developing domain of synthetic polymers for anterior cruciate ligament reconstruction still has a lot of potential. In addition, lots of nanostructured materials, made of nanofibers or in the form of ceramic/polymeric nanocomposites, are getting interest of several studies due to their potential use as engineered scaffolds that mimic the native surface composite of cells, increasing the chances for tissue regeneration. Here, we review the last 20 years of literature in order to obtain a good understanding on the use of synthetic grafts made by nano- and polymeric materials for ACL reconstruction, and to trace perspectives on the future development of the fiel