Do all ACL injuries require surgery?

No.
This is a common misconception. In fact up to almost 4 in 5 people may be able to recover without having surgery (Dhillon, 2014; Neuman, 2008).

Can a complete ACL tear heal?

Yes!

The ACL has a high healing capacity in humans. Despite the common misconception that the ACL can’t heal due to poor blood supply, there are multiple studies which prove the ACL can in-fact frequently heal. (Costa-paz, 2012; Filbay 2022; Filbay 2023; Marangoni, 2018; Roe, 2016; Ihara, 2017).

Do I need an MRI?

No.

History of the mechanism of injury, and signs and symptoms are sufficient to accurately diagnose an ACL tear. Clinical tests such as the Lochmans test is as accurate as MRI in diagnosing ACL injuries.
MRI may be useful if the clinical presentation is unclear (Filbay, 2019; Meuffels 2012; RACGP Clinical Guidance for MRI Referral).

Does not having surgery put me at greater risk of re-injury?

No.
Provided you complete at least 3-6 months of constructive exercise rehabilitation, you are at no greater risk of further injury (Filbay, 2015; Filbay, 2017; Frobell, 2010; Frobell, 2013; Rahardja, 2020; Reijman, 2021).

Do I need surgery to return to pivoting sports?

No.
Surgery is not a prerequisite to return to return to high level pivoting sports. Surgery does not increase your chances of returning to sport, or performance, and does not allow for a quicker recovery (Frobell, 2013; Grindem, 2016; Keays, 2019; Mykelbust, 2003; Weiler, 2015; Weiler, 2016).

Does surgery reduce my chances of developing osteoarthritis?

No.
In-fact the process of drilling holes and cutting tissue in surgery is a secondary trauma that causes prolonged increase in knee inflammation which may increase your chances of developing osteoarthritis (Bowes, 2009; Filbay, 2017; Ivensen 2019; Larsson, 2017; Lohmander, 2004; Wang 2020).

Do I need surgery if I also have a meniscal tear?

No.
There is no quality evidence to suggest that if you have a meniscal tear in association with and ACL tear, that surgery is necessary or better. In-fact having a meniscal tear, and having ACL surgery is a risk factor for poorer long term outcome, compared to having a meniscal tear and not having ACL surgery (Ekas, 2019; Filbay, 2017; Filbay, 2018).

Is having surgery cheaper?

No.
There is no economic benefit to having ACL surgery. Recovering from an ACL injury with rehabilitation alone is up to greater that A$24,000 cheaper than reconstructive surgery (Kiadaliri, 2016).

How do I know if i’m a candidate for non-surgical rehabilitation?

It is recommended that everyone begin with rehabilitation as the primary treatment for ACL injuries and only have surgery if following rehabilitation, surgery is considered necessary (Filbay, 2019; Winston Churchill Memorial Trust, 2018; Zadro and Pappas, 2019).

What about when I’m old and my muscles aren’t as strong?

Even at up to 37 years post ACL injury, studies show it is possible to be symptom free and function at a high level. And there is no benefit to surgery compared to rehabilitation alone (Filbay, 2019; Yperen, 2018).

What happens if I fail rehabilitation?

If following a 3-6 month period of rehabilitation, you continue to experience instability or poor function, the option for reconstructive surgery is still available. Importantly delayed reconstruction following a period of rehabilitation leads to better long term outcomes than early reconstruction (Failia, 2016; Filbay, 2015; Filbay, 2017; Frobell, 2010; Frobell, 2013).

I don’t have full range of motion in my knee, can I get feel range of motion back?

Yes.

Restricted range of motion is common following ACL injury, the most common cause of restricted range is “arthrogenic muscle inhibition” (AMI) which is caused by muscle spasm (commonly in the hamstring) and muscle inhibition (commonly of the vastus medialis) which results in pain and restriction to normal movement. Range is rarely restricted due to a structure within the knee blocking movement. Range can be improved by performing exercises that assist the hamstrings to relax, and vastus medialis to contract (Delaloye, 2018).

Will ACL surgery allow me to return to work earlier?

No.

A randomised controlled trial comparing ACL surgery to rehabilitation by Kumar (2018) found that those who did not have surgery, returned to work at on average 14 days, compared to on average 86 days in those who had ACL surgery.

Will I be at greater risk of a knee replacement in the future?

While evidence suggests the risk of total knee replacement following ACL injury is increased it still remains very low.
A systematic review of 152 390 ACL-injured patients estimated the risk of knee replacement after ACL injury to be 0.7% (Nguyen, 2020).