Anterior cruciate ligament (ACL) is one of the most commonly injured ligaments of the knee, with incidence of ACL injuries estimated to be approximately 200,000 annually in the US. Most of these injuries occur in younger patients, who may later develop osteoarthritis. To date, both allografts and autografts are used for ACL reconstruction, both of which has several shortcomings. Allografts, while used less frequently, are often associated with a possibility of disease transmission, as well as higher cost. While autografts have been used as a standard for ACL reconstruction, as they are biomechanically stronger than allografts, they are associated with donor site morbidity.
University of Michigan researchers have developed a tissue engineered 3-dimensional bone-ligament-bone graft constructed from bone marrow stromal cells with synthetic scaffolding, which may be used for ACL reconstruction. While grafts to date have been developed to maximize biomechanical strength, this technology allows the graft to develop in response to its microenvironment, and may prevent stiffness and degradation. Upon implantation in an animal model of ACL injury, the graft was vascularized and innervated, with histology comparable to native tissue. As the graft develops with the patient, it is expected that the limitations of current approaches to ACL reconstruction such as stiffness and graft degradation may be obviated.
Applications and Advantages
- Alternative to autolografts and allografts for ACL reconstruction
- Functional 3D bone and nerve tissue without-nl-synthetic scaffolding
- Incorporation into native tissue