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ACL surgery vs exercises for ACL rehab

ACL Surgery vs Exercises For ACL Rehab

Dominic your friendly physio here with a big one. The topic of ACL surgery vs. exercises for ACL rehab is an area where physiotherapists are getting more and more evidence behind what works, and what doesn’t work and why for ACL injuries.

A quick TLDR off the top with the highlights, then if you’re ready, dive deeper below.

Key Points

  1. An ACL reconstruction is not the only way to manage an ACL injury
  2. Exercises for ACL Rehab for the right person yields similar outcome 
  3. It is also possible to return to elite sports with exercises for ACL rehab; potentially with shorter rehab periods than surgery
  4. The lower the sporting demands on your knee, the better the chances of returning to sport
  5. Multiple factors that influence your recovery/ return to sport should be considered to optimise your outcomes
  6. There are no shortcuts. Regardless of approach, ACL surgery or exercises for ACL rehab. Investing time in quality rehab is necessary.

Recent studies recommend starting exercises for ACL rehab day 1 post-injury (12,13).

If you aren’t already doing that, it’s time to start.

Book an in-clinic physio or telehealth physio session to kick start your exercises for ACL rehab now.

ACL Injuries

Let’s be honest.

An ACL injury is not like any common sports injury.

You can’t just rub a torn ACL out with a sports massage.

The first things that come to mind are often the dreadful thought of missing the rest of the season. Then the fear of returning to the sport you are playing at the same level. Additionally, having to deal with a 6 to 9 months long intensive rehabilitation doesn’t sound exciting to everyone.

Having had my fair share of traumatic sports injuries, I can relate how it can be both depressing and anxiety-inducing to deal with an ACL injury. Knowing what you’re in for over the next 6 – 9 months can help you with the stress of managing the uncertainty.

If you’re like many of us, chances are you have GOOGLED for answers and still befuddled with the conflicting suggestions. Some recommending ACL reconstruction surgery and others non-operative active rehabilitation.

Let me help you make sense of it all.

acl injury & acl treatment

You can read more on our ACL Injury Guide here.

Firstly, What Exactly is an ACL?

The ACL – A.K.A the Anterior Cruciate Ligament (but not always crucial actually) is one of 4 ligaments which surrounds your knee. The ACL connects the thigh bone and the shin bone. Its primary role is to provide passive restraint, preventing the shin bone from sliding ahead of the thigh bone.

what is a ligament and what do ligaments do?

Learn all about ligaments in our Anatomy Class Series here.

History of ACL Surgery Rehabilitation

Traditionally, when you have an ACL injury, you will have an ACL surgery, known as a reconstruction.

It makes logical sense.

You tear it, the surgeon stitches it.

Job done.

Well, not really…

Many sports fans remember their favourite sports stars on TV twisting their knees and ended up having to have an ACL surgery reconstruction in order to get back to sport.

You might have read that knees with an ACL injury are associated with early knee osteoarthritis.

To many, an ACL surgery reconstruction makes sense if you have sporting aspirations and wish to delay early arthritis.

Interestingly, research has shown that even with an ACL surgery reconstruction you could still feel unsteady in your knees. Returning to sport back to the same level may not be possible for all and risk of re-injury remains high.

  • Only around 65% of recreational and 83% of professional athletes were able to return to sports at pre-injury level. (1,2)

What’s even more surprising is that later studies that compared people who undergo an ACL surgery reconstruction vs active rehabilitation found that the surgery did not actually prevent or delay the onset of early knee osteoarthritis. (3,4)

Such sub optimal outcomes with ACL surgery motivated further investigations into the best treatment for ACL injuries.

This is what we found…

  • Pre-operative quadriceps strength was the single most important predictor for knee function 2 years after ACL surgery. Also, pre-op deficits were persistent 2 years after surgery (5)
  • A 6-week progressive prehab program for subjects undergoing ACL surgery led to improved knee function during hopping test and in areas related to knee pain, swelling, function and activity-level (6)
  • Return to sport is associated with increased quadriceps strength, higher activity, greater knee confidence and reduced phobia with movement (7)

These studies highlight the importance of prehab and addressing non-physical factors to achieve a better ACL surgery outcomes.

Nowadays, most surgeons would recommend you to attend prehab prior to any ACL surgery intervention.

Active Rehabilitation Exercise For ACL Rehab

Against convention, there is also a small but growing group of people who have successfully returned to pivoting and cutting sports with active rehabilitation alone. DeJuan Blair, the legend, actually played in the NBA for the San Antonio Spurs for multiple seasons without an ACL in both of his knees!

Researchers have spent time investigating the efficacy of active rehab alone on ACL injuries.

They found that it is possible to return to pivoting sports, even in elite level sports with active rehabilitation. For sports where the degree of pivoting and cutting is less, the odds are even better.

A study by Grindem et al compared return to sports at 1 year after ACL surgery versus active rehab. (8)

  • The return to pivoting sports rate was similar for patients in the active rehab group (54.8%) and the surgery group (61.9%).
  • Further analysis of patients who were in the active rehab group who were involved in higher demand pivoting sports prior to injury has a lower likelihood of returning to sport (54.8%) compared those who were participating in sports than were less demanding on the knee (88.9%).

Another study by Myklebust et al surveyed elite handball players 6 to 11 years after they have ruptured their ACL. (9)

Among those who underwent ACL surgery, 58% returned to play at pre-injury levels vs 82% among players who had active rehabilitation alone.

Patients who opted for active rehab also have the potential to return to sport earlier as patients who underwent ACL surgery require additional rest to recover from surgery. An extended recovery would also be required to cater for healing of the reconstructed graft.

High-quality studies have also recommended delaying ACL surgery where possible. It has been found that patients who had early reconstruction had poorer outcome compared to delayed surgery or active rehab alone.

It is suggested that early surgery can contribute to a “second insult” to the initial knee injury which further impedes healing (14)

As with all surgeries, an ACL reconstruction comes with a risk of infection, blood clots and specifically for ACL surgery, long-term knee pain, weakness or stiffness.

Finally, if you hate future dramas here’s some numbers worth crunching as well:

  • Up to 1 in 5 people who have an ACL reconstruction undergoes additional surgery to the operated knee within 6 years
  • Up to 1 in 4 individuals suffer a graft re-rupture or ACL rupture on the opposite knee within 15 years of ACL reconstruction

Now, active rehabilitation really sounds like an attractive alternative over ACL surgery. But before getting hopeful and jumping onto the active rehab bandwagon, there are also qualifications that you should meet to improve your chances of success with active rehab.

How To Improve Your Chance of Success

Studies have used the below criteria to screen for patients after an initial early phase rehab to decide who would potentially do well with non-operative management. (10)

  • A hop test performance that is at least 80% of the other side
  • A score of ≥ 80% on a survey related to knee symptoms and function during activities of daily living and dynamic tasks
  • Achieving ≥ 60% capacity to perform activity at the same level as before injury
  • ≤ 1 episode of the knee giving way since the injury

Those who met the criteria and followed up with active rehabilitation did not differ in outcome with those who managed the ACL injury surgically.

However, it should be noted that patients with complex knee injuries involving multiple structures such as other knee ligaments, cartilage and meniscus are excluded from these studies. These populations often have better outcomes with surgery.

The Bottom Line

Surgery now or start your exercises for ACL rehab?

A recent study of active patients with ACL injuries found that there were no significant differences between those who had immediate reconstructive surgery followed by rehabilitation versus those patients who had rehabilitation first, then offered the option of undergoing surgery up to 12 months later .(11)

This tells us that exercises for ACL rehab and an active rehabilitation should always be the primary approach before deciding on any further surgical management.

exercises for acl rehab expert and physiotherapist dominic tan

Let’s get started on your exercises for ACL rehab now.

Book in with our team online here.


  1. Ardern, C. L., Webster, K. E., Taylor, N. F., & Feller, J. A. (2011). Return to sport following anterior cruciate ligament reconstruction surgery: a systematic review and meta-analysis of the state of play. Br J Sports Med, 45(7), 596-606. doi:10.1136/bjsm.2010.076364
  2. Lai, C. C. H., Ardern, C. L., Feller, J. A., & Webster, K. E. (2018). Eighty-three per cent of elite athletes return to preinjury sport after anterior cruciate ligament reconstruction: a systematic review with meta-analysis of return to sport rates, graft rupture rates and performance outcomes. Br J Sports Med, 52(2), 128-138. doi:10.1136/bjsports-2016-096836
  3. Poulsen, E., Goncalves, G. H., Bricca, A., Roos, E. M., Thorlund, J. B., & Juhl, C. B. (2019). Knee osteoarthritis risk is increased 4-6 fold after knee injury – a systematic review and meta-analysis. Br J Sports Med. doi:10.1136/bjsports-2018-100022
  4. van Yperen, D. T., Reijman, M., van Es, E. M., Bierma-Zeinstra, S. M., & Meuffels, D. E. (2018). Twenty-year follow-up study comparing operative versus nonoperative treatment of anterior cruciate ligament ruptures in high-level athletes. The American journal of sports medicine, 46(5), 1129-1136.
  5. Eitzen, I., Holm, I., & Risberg, M. A. (2009). Preoperative quadriceps strength is a significant predictor of knee function two years after anterior cruciate ligament reconstruction. British journal of sports medicine, 43(5), 371-376.
  6. Shaarani, S. R., O’Hare, C., Quinn, A., Moyna, N., Moran, R., & O’Byrne, J. M. (2013). Effect of prehabilitation on the outcome of anterior cruciate ligament reconstruction. The American journal of sports medicine, 41(9), 2117-2127.
  7. Czuppon, S., Racette, B. A., Klein, S. E., & Harris-Hayes, M. (2014). Variables associated with return to sport following anterior cruciate ligament reconstruction: a systematic review. British journal of sports medicine, 48(5), 356-364.
  8. Grindem, H., Eitzen, I., Moksnes, H., Snyder-Mackler, L., & Risberg, M. A. (2012). A pair-matched comparison of return to pivoting sports at 1 year in ACL-injured patients after a nonoperative versus operative treatment course. The American journal of sports medicine, 40(11), 2509.
  9. Myklebust, G., Holm, I., Mæhlum, S., Engebretsen, L., & Bahr, R. (2003). Clinical, functional, and radiologic outcome in team handball players 6 to 11 years after anterior cruciate ligament injury: a follow-up study. The American journal of sports medicine, 31(6), 981-989.
  10. Wellsandt, E., Failla, M. J., Axe, M. J., & Snyder-Mackler, L. (2018). Does anterior cruciate ligament reconstruction improve functional and radiographic outcomes over nonoperative management 5 years after injury? The American journal of sports medicine, 46(9), 2103-2112.
  11. Frobell, R. B., Roos, H. P., Roos, E. M., Roemer, F. W., Ranstam, J., & Lohmander, L. S. (2013). Treatment for acute anterior cruciate ligament tear: five year outcome of randomised trial. Bmj, 346, f232. doi:10.1136/bmj.f232
  12. Eitzen, I., Moksnes, H., Snyder-Mackler, L., & Risberg, M. A. (2010). A progressive 5-week exercise therapy program leads to significant improvement in knee function early after anterior cruciate ligament injury. Journal of Orthopaedic & Sports Physical Therapy, 40(11), 705-721.
  13. Hartigan, E., Axe, M. J., & Snyder‐Mackler, L. (2009). Perturbation training prior to ACL reconstruction improves gait asymmetries in non‐copers. Journal of Orthopaedic Research, 27(6), 724-729.
  14. Filbay, S. R., Roos, E. M., Frobell, R. B., Roemer, F., Ranstam, J., & Lohmander, L. S. (2017). Delaying ACL reconstruction and treating with exercise therapy alone may alter prognostic factors for 5-year outcome: an exploratory analysis of the KANON trial. British Journal of Sports Medicine, 51(22), 1622-1629.