The ideal timing for ACL repair is after the joint swelling has gone down and the patient can move through the full range of motion. There should be no problem walking normally (without a limp). There should be no swelling.
Studies show that a strong quadriceps muscle before ACL repair is linked to a faster recovery after the operation. Delaying ACL repair gives the athlete a chance to strengthen the quadriceps muscle first.
Regaining strength and function in the first months depends somewhat on the width of the tendon graft used to repair the torn ACL. Large tendon width has a better outcome early on. One study showed that results are the same after two years no matter what tendon width is used.
For the athlete who wants to get back to training and competition quickly, tendon width and muscle strength are two key factors. These should be considered when making the decision about when to schedule the operation.