The envelope of function in anterior cruciate ligament injuries

The range of load that can be applied to a knee joint without causing structural or metabolic failure can be termed envelope of function. Injuries to the knee joint, such as anterior cruciate ligament (ACL) injuries, may significantly diminish the envelope of function. The goal of a successful treatment program for patients with ACL injuries is to restore normal physiologic knee function and thus restore the physiologic envelope of function. Recent advances have improved the outcomes in ACL surgery. However, full restoration of physiologic knee function and normal knee kinematics usually is not achieved. Therefore, surgical approaches that restore the normal anatomy of the ACL may further contribute to the improvement of outcomes and may further diminish the discrepancy between the postoperative envelope of function and the physiologic envelope of function.