Posted September 21, 2016By Tim Koba, MS, ATC
ACL injuries continue to be a hot topic in the sport world. A big reason is that even though they are still not very common, percentage wise, they have a large impact on long term joint health, recovery, cost and ability to return. As reconstruction techniques continue to evolve, athletes are able to return to play, but how successfully?
After surgery, the treatment consists of rehabilitation to regain motion, function, proprioception strength and control. Once athletes have completed about 6-9 months of rehab, they return to sport. Here’s the sobering news: Of those who suffer an ACL reconstruction, only 65% return to their pre-injury level of sport, with only 55% returning to competitive play. Even more discouraging is the fact that of those who return to sport, up to 1 in 5 will suffer a tear to their reconstructed knee, or the ACL on the non-reconstructed side.
In order to determine what risk factors existed, and ways to modify them, researchers looked at elite soccer players who had their ACL reconstructed and then followed them. They looked at the type of surgery they had, their rehabilitation process and their return to sport. What they discovered was that athletes who did not meet certain bench marks in rehab were 4 times more likely to have another ACL injury. The following table shows the exercises and the discharge criteria that were deemed successful.
Discharge tests and criteria used during the study period
|6 part return to sport tests||Discharge permitted when criteria was met|
|Isokinetic test at 60, 180 and 300 degrees/sec||Quadriceps deficit <10% at 60 degrees/sec|
|Single leg hop||Limb symmetry index >90%|
|Triple hop||Limb symmetry index >90%|
|Triple crossover hop||Limb symmetry index >90%|
|On field sport specific rehab||Fully completed|
|T test||<11 sec|
In addition to the tests above, athletes who had lower hamstring-to-quadriceps strength ratios were also more likely to injure their ACL. Since strong hamstrings act as an assistant to the ACL, weakness there can mean more stress on the ligament.
This study highlights a couple of key points when rehabilitating ACL injuries.
- Prior to return to play, athletes should be fully recovered with equal strength bilaterally
- They should be able to seamlessly perform multidirectional drills
- Athletes should have adequate hamstring strength. Most of us do not have access to isokinetic testing, but spending time having athletes perform hamstring strengthening during their rehabilitation is essential.
Kyritsis, P. et. al. (2016). Likelihood of ACL graft rupture: not meeting six clinical discharge criteria before return to sport is associated with a four times greater risk of rupture. British Journal of Sports Medicine, 50. http://bjsm.bmj.com/content/early/2016/05/23/bjsports-2015-095908.abstract
About the Author
Tim Koba is an Athletic Trainer, strength coach and sport business professional based in Ithaca, New York. He is passionate about helping others reach their personal and professional potential by researching topics of interest and sharing it with others. He contributes articles on injury prevention, management, rehabilitation, athletic development and leadership.