What is the key determinant for returning to sport after ACL reconstruction?

The key determinant for returning to sport after ACL reconstruction is graft maturation. This process is critical because it refers to the biological healing and integration of the graft within the knee joint. After ACL reconstruction, proper incorporation of the graft into the surrounding tissue is necessary to ensure stability and function of the knee during athletic activities.

Graft maturation typically involves a series of biological and mechanical changes that can take several months. The newly placed graft must undergo a remodeling phase where it becomes integrated into the surrounding tissue, and its tensile strength gradually increases. If a patient returns to sport before the graft has fully matured, there is a significant risk of re-injury or graft failure.

While factors such as the patient's age and physical fitness, physical therapy compliance, and the type of sport involved play roles in the rehabilitation process, they do not supersede the importance of graft maturation. Without this critical healing phase being sufficiently complete, even highly compliant patients or those engaged in lower-risk sports may not be ready functionally or biomechanically to resume athletic activities safely.