- many techniques described with one or two tibial and one or two femoral tunnels
 - much biomechanical data confirms that both bundles are necessary to restore
            - ACL function
                  - main findings are that PL bundle contributes to rotational stability closer to full extension
                           - Distribution of in situ forces in the anterior cruciate ligament in response to rotatory loads. 
                           - Single- versus two-femoral socket ACLR technique: Biomechanical analysis using a robotic simulator.
                  - AM bundle reconstruction restores tibial anteroposterior translational stability but not rotational stability
                           - The effectiveness of reconstruction of the anterior cruciate ligament with hamstrings and patellar tendon . A cadaveric study comparing anterior tibial and rotational loads. 
                  - clinical advantages versus single bundle technique not yet identified.
                           - Anatomical reconstruction of the anterior cruciate ligament in goats.
                           - Biomechanics of a double prosthetic ligament in the anterior cruciate deficient knee
                           - A comparative study of single- and double-bundle ACL reconstructions in sheep
                   - difficulty is how to measure/quantify improved rotational stability
                   - technical complexity and complications still need to be overcome before it becomes gold standard.
                   - multiple techniques published with no established benefit yet
                           - Anatomic double bundle ACL reconstruction: a literature review