Returning to sport after ACL reconstruction represents a significant challenge. 65% percent of patients will return to pre-injury levels of sport after surgery and 35% percent of these patients will subsequently re-injure their ACL or contralateral ACL. As such assessing and ensuring physical readiness to return to sport is essential to reduce risk of re-injury.
When is the right time to return to sport after ACL surgery?
Most surgeon’s will advise their patients that they will be able to return to sport 9-12 months after ACLR surgery, however the decision shouldn’t be based on time alone. Ideally patients should only return to sport after achieving milestones that signify full restoration of strength, power, proprioception and control.
Equally some patients may achieve all of the required milestones earlier than 9 months and feel ready to return to sport earlier, however general advice would be to wait until at least 9 months before attempting to do so. The reason for this is the time it takes for the grafted ligament to reach its maximum tensile strength. Research suggests that at 9 months the new graft will be at 80-90% of its maximum strength, a level that is deemed safe to return to sport. Some practitioners may advise postponing return to sport until 12 months as this has been shown to further reduce the risk of re-injury, as the graft will be closer to its maximum strength.
How do I know I’m ready to return to sport after 9-12 months?
Typically patients must pass a battery of tests and psychologically feel confident to return (measured via questionnaire results). The testing procedures are used to assess limb symmetry between the operated and non-operated leg, this is termed the Limb Symmetry Index. The limb symmetry index takes into consideration specific strength and plyometric performance of each limb to assess the level of recovery. Ideally patients will have a limb symmetry index of >95% before being deemed ready for return to sport. Where possible pre-op strength measurements taken after a prehab program are used as comparison values, as these are thought to provide more representative comparison measures. In addition to achieving the desired Limb Symmetry Index patients will be required to perform a number of dynamic tests relevant to their sporting needs (ie agility/sprint/jump).
My rehab has been great, I’ve achieved the milestones and I’m in the appropriate time frame, can I play this weekend?
The short answer is you probably shouldn’t. Usually as an extra layer of safety patients will be re-introduced to restricted training participation (ie non contact/non competitive drills, reduced training duration) and gradually build up to full training participation. Some of this may occur concurrently with the final stages of rehab. Once the patient is managing full training participation without soreness or swelling post training it’s typically recommended to complete at least 3 weeks of full training (some would suggest longer to reduce risk of re-injury) before returning to match play (generally not full minutes/game duration initially). This is because match/game play is typically performed at higher intensity, and is less controlled or predictable.
I’ve returned to play successfully, can I forget about my knee now?
Hopefully after completing rehab you’re able to play uninhibited without apprehension of your knee, however it is still recommended to maintain some level of ongoing rehab/injury prevention exercise after returning to play. Studies have shown that ongoing injury prevention programs can significantly reduce the risk of re-injuring your ACL. These programs typically consist of a combination of strength, proprioception and plyometric exercise. Beyond sport, keeping your knee strong also reduces the impact of degenerative or arthritic changes later in life.
