Yet to Ace the ACL: What can we Improve?

This article was first published on Pulse.

I have had a passion for ACL injuries since my undergraduate physio days where during a placement I saw Dr. Jun Nagamori perform a reconstruction. It just amazed me and so began my understanding of this all too common and debilitating injury. One of the first “rehabs” I did of one was unluckily for me my wife who ruptured her ACL playing netball in my first year out. For me it allowed me to see how it can impact things in everyday life as well as seeing the gruelling pain and work required to recover – in the clinic and at home. Over 10 years on and her ACL is still intact and she has returned to netball. Since then I have been involved in over 250 rehabilitations of ACL injuries including hamstring, tib post and patella tendon, autograft and allograft, conservative and even the odd LARS. To date I can only recall one re-rupture and that was one very keen soccer goalie who returned to play a grand final at 10 weeks following hamstring autograft – needless to say he was aware of the risks and happily returned a grand final winner and re-did the surgery (and a “proper” rehab). I am sure there have been others fail but I haven’t heard back from them.

So it leaves me to ask how do we ALL get this so wrong? From surgical techniques to rehab to return to sport criteria. With only 55% returning to competitive sports and a re-rupture rate of up to 25% (Ardern et al 2014) surely there must be a better answer.

With only 55% returning to competitive sports and a re-rupture rate of up to 25% (Ardern et al 2014) surely there must be a better answer.

We all agree that there are key things to focus on when completing a rehabilitation and now we have a series of guidelines to aim for with criteria for return to sport (Kritsis et al, 2016). However, these guidelines are difficult to measure in the standard clinic relying on people going back to training to do them unsupervised. How many clinics have the space for a T-Test or can measure hamstring and quads strength at 60°/s. How reliable is a client’s version of “full sports training” when stinging to get back and be “cleared”???

So what do we in the everyday clinic, treating people do? What sort of confidence enables us to say you are at reduced risk of re-injuring (or injuring the other side) if you can (insert any arbitrary single leg functional test in here). Bear in mind you only need 3/5 strength to perform a controlled move in a clinical setting.

I know one leading surgeon just says do a single leg squat and if it “looks good” you’ll be fine. From here it doesn’t matter what the physio says. Needless to say, I have seen a few re-ruptures operated on by different surgeons following this.

Kinetisense Assessment

So what do we do??? It is too expensive and space consuming for us to invest in full on testing equipment (maybe one day) but most of us have access to hand held dynamometry, EMG, treadmills and video. Some of us more fortunate may have invested in DorsaVi, NordBord and easy to use motion capture systems such as Kinetisense. These tools, which are a lot more affordable may help us pave the way to give more confidence to return to sport and to guide more specific treatment programs defining real individualised issues and compensations.

Physiological tests we can perform in the clinic nowadays include

  • Hip abduction, adduction and extension strengths (using HHD) and relate to norms and equality (Abd/Add = 1.15; Abd 25% of BW; Extension 30% of BW is a good start)
  • Hip external and internal rotation HHD (Hip ER at 0° 35% stronger than IR) and range – often overlooked
  • Tibial internal and external rotation laxity and HHD (more on this later – but active strength, stability and control of the tibial rotators (including the grafted semiten) surely have an impact on a tibial rotation re-injury)
  • Hamstring strength with HHD or Nordbord (if you can get access to a Nordbord and do Nordic curls – we will tell you why later)
  • Quadricep EMG and HHD
  • Calf strength, range and function (get the magic 25 out with good quality timing (EMG)between lat and med gastroc)
  • Balance tests such as SEBT

Clinical strength, range and control measures are great but we need to relate them to functional activities. Here are some things newer technologies allow us to measure in the clinic

  • Tibial inclination (how far the knee bends during a squat, hop, jump or step down) - 45° ideal
  • Varus whip – how fast the knee moves from varus to valgus during movement (less than 100°/s)
  • Consistency of repetitive movements - 5 movements in a row within 5° of varus or valgus (I am not too fazed whether there is increased valgus as long as it is consistent and gets there under control (Varus whip))
  • Difference from each leg for ground reaction forces during running and stopping and general limb asymmetries
  • How much spinal and pelvic tilt and shoulder, hip and trunk rotation occurs during functional movement – the single leg squat might look great at the knee but compensations are easy to do and can come undone on the park under fatigue and in greater demand.  Consistency is the key.  Plus if their sport specific task involves spinal or pelvic tilt or shoulder/hip rotation perhaps we should be doing strength and stability training in these positions.

Knee Control Live Assessment

Knee Control Live Assessment

The important thing about these measures is we can reassess under fatigued circumstances and see EXACTLY what changes and then re-train that and keep re-training things that are relevant. And it can all be done easy enough these days in the clinic. When you identify the relationships between physiological measures and objective functional tests you see patterns the naked eye doesn’t or at least helps to confirm and then measure the change. 

If you’re not assessin’ you’re guessin’

The key for us know is standardising these measures and relating them to the tests described by Kritsis et al in the BJSM in 2016 and then using all these measures to reduce the risk of re-rupture and even better coming up with assessment guidelines to reduce them in the first place!! 

The Ace your ACL assessment in progress

Let’s realise that no one-size fits all rehab program works and understanding what and how to assess and then how to interpret is critical.  If you want more information on how the Ace your ACL assessment can be used to guide treating your ACL patients, improve their compliance and reduce their risk of re-rupture please get in contact with me.  The more we see the more fun things we can find out about this debilitating injury and work together to deliver better outcomes.

Stay tuned for some more insights into a new graft surgery and better ways to assess and train the semitendinosus post-operatively – perhaps it’s more important than the VMO!!

Ardern, C.L., Taylor, N.F., Feller, J.A.,& Webster, K.E.(2014). Fifty-five per cent return to competitive sport following anterior cruciate ligament reconstruction surgery: an updated systematic review and meta-analysis including aspects of physical functioning and contextual factors. British Journal of Sports Medicine, 48, 1543-1552. doi: 10.1136/bjsports-2013-093398
Kyritsis, P., Bahr, R., Landreau, P., Miladi, R., & Witvrouw, E. (2016) Likelihood of ACL graft rupture: not meeting six clinical discharge criteria before return to sport is associated with a four times