Hamstring autograft has been a widely used graft option for ACL reconstruction surgery for years. Data over the last decade, however, has called into question its performance versus other autograft options particularly when it comes to the rate of re-tear. One potential reason for a higher rate of re-tear may be that hamstring grafts tend to be smaller in diameter compared to patellar tendon autografts, for example. Historically, a hamstring graft diameter of 8 mm has been considered a critical value that could determine long-term success versus failure, however an exact graft diameter has not been identified. Dr. Raffy Mirzayan, MD from Kaiser Permanente Baldwin Park joins us to discuss his study aiming to find that threshold diameter for hamstring autograft. We discuss how the fear of a smaller diameter graft may influence surgeons to look at other options such as quadriceps tendon autograft.