This image is from a study published by a well-known American professor. The colored portion of the figure shows the location of the normal ACL femoral stop, blue is the anterior internal bundle, and yellow is the posterior external bundle. The 10mm circle in the a figure is the ideal location and minimum diameter for doing a single bundle reconstruction. The 6mm circle in the b figure is the ideal position and minimum diameter of the posterior external bundle for double-bundle reconstruction, and the 8mm circle is the ideal position and minimum diameter of the anterior internal bundle for double-bundle reconstruction. You Tian, Department of Sports Medicine and Rehabilitation, Peking University Shenzhen Hospital From the figure, it is easy to see that the normal ACL femoral stop is not circular but nearly oval, so a large and thick circle is obviously not in line with the spirit of anatomical reconstruction, while two small circles combined together are closer to the oval shape and more in line with the normal human body pattern. Therefore, anatomical double bundle reconstruction should be the first choice for ACL reconstruction.