ACL: True or False?

There are many misconceptions surrounding ACL injury, ACL rehab and ACL injury prevention. More that I can cover in great detail today. However, what I will discuss are 2 common misconceptions that I feel need to be shared to a wide audience, so that we build trust in our athletes, patients, coaches and parents and avoid building false hope.

True or False #1: ACL injury prevention programs, prevent ALL ACL injuries.

Answer: False They don’t. They simply reduce the risk of sustaining a future ACL injury. Current research says that we can reduce all ACL injuries by 50%, and non-contact ACL injuries in females by 67% (Webster & Hewett, 2018)

The terminology that we use regarding “injury prevention programs” needs to change. Despite it’s best intentions, “injury prevention programs” can build false hope with coaches, athletes and parents who may lose trust when injuries actually occur. 

The reality is, if we’re playing sport, injuries unfortunately are a part of the game despite the best preparation of each individual athlete. All we as can do as health professionals is reduce the risk of injury with appropriately conducted warm up routines prior to each training session and game.

Don’t get me wrong. We still need to be performing these “injury prevention programs”. Programs like The FIFA 11+, the PEP, the Netball KNEE and the AFL Footy First programs are excellent programs that reduce the risk of ACL injuries and all lower limb injuries. They just don’t prevent them all...

Cases in point: 1) 7 ACL injuries occurred in 2479 “injury prevention program” participants vs 14 ACL injuries in 2085 control group participants (Walden et al, 2012; youth female soccer).

2) 7 ACL injuries occurred in 583 “injury prevention program” participants vs 18 ACL injuries in 852 control group participants (Gilchrist et al., 2008; women’s soccer).

3) 6 ACL injuries occurred in 1885 “injury prevention program” participants vs 67 ACL injuries occurring in 3818 control group participants (Mandelbaum et al., 2005; youth female soccer).

True or False #2:

Passing return to sport tests following ACLR guarantees your safety from ACL re-injury upon return to sport.

Answer: False. In recent times there has been a positive trend towards ACLR patients being encouraged to pass functional tests, in addition to the orthopaedic surgeon’s assessment prior to returning to sport. 

These tests which are described in the literature are, (although not limited to):

- Isokinetic strength testing of quads and hamstrings at 60deg/sec, 180deg/sec and 300deg/sec (Pass: 90% limb symmetry) - Single leg hop test (Pass: 90% limb symmetry) - Triple leg hop test (Pass: 90% limb symmetry) - 3x cross-over hop test (Pass: 90% limb symmetry) - Agility T-Test (Pass: faster than norm values. Dependent on age, sex, sport) - Completed on-field sport specific rehabilitation

However, passing this battery of functional tests only reduces your risk of ACL re-injury. It does not guarantee your safety.

Case in point: 

In a recent study of professional soccer players by Kyrytsis et al (2016), they found that 12 of 116 players (10%) who were fully discharged by medical staff from ACLR rehabilitation (ie. passed all of the return to sport testing criteria outlined above) reinjured their ACL. However, returning to sport without being officially discharged by medical staff from rehabilitation (42 players), resulted in 14 ACL re-injuries (33%). 

Therefore, and based on this study, you still have a 10% chance vs 33% chance of ACL re-injury despite being medically cleared to play. If I was an athlete looking to return to sport, I certainly know what odds I would like to take...

For more on all things ACL injury, download my ACL rehab guide by clicking here, and watch my online ACL tutorials by clicking on the following links:

1) www.mickhughes.physio/lectures (delayed access, password required)

2) www.learn.physio/videos/100018 (instant access)