The absence of adequate options to restore full knee joint function through anterior cruciate ligament reconstruction prompts the need to develop new ligament replacement strategies. Recent focus within the ligament engineering field has been on the establishment of appropriate anterior cruciate ligament graft design requirements and evaluation methods. A range of biomaterials and graft constructions has been explored in an attempt to identify the optimal ligament replacement. Thorough and standardized evaluation methods are required throughout all phases of development, from initial in vitro bench screening through a large animal in vivo model. The initial positive clinical, gross pathologic, histologic, and mechanical results from a 12-month in vivo goat study demonstrate the potential of bioengineered ligament devices.