At Asia Physio, we have been operating in the ski fields of Japan for over 17 years and have seen thousands of ACL tears of all types, usually a day or two post-injury. We are in a unique position to be able to help these patients during their time of need, and we take our responsibility very seriously. Consequently, we keep a close eye on the latest developments in ACL injury management, a fascinating and controversial area. To say the past few years have been a turbulent time in ACL management would be an understatement. Evidence for best practice care for ACL has changed; however, clinical practice is still adjusting. Several long-held beliefs have been proven false, and these beliefs are commonly used to justify surgery. Best practice care is now to wait for a minimum of 12 weeks post-injury to a) give the ACL a chance to heal b) improve function and strength to see if adequate stability can be achieved without surgery

Lola Colless in Niseko

The following is a list of beliefs that many in the industry will present as fact, but are in fact demonstrably false. This is not a scientific publication and is intended for the general public, but there are studies linked below the article.

1.   ACL reconstructive surgery reduces the risk of Osteo Arthritis

This line has convinced hundreds of thousands of people to have ACL reconstructive surgeries. But there is enough evidence to state with conviction that it is invalid. And even worse, the emerging body of evidence shows greater OA rates in people with a reconstruction.

A 2021 umbrella systematic review showed a higher risk of OA on X-ray with people who had reconstruction than people who did not. Other studies showed no relation between treatment strategy and OA risk. Another study showed an increase in inflammatory cytokines up to 5 years after surgery and more change in cartilage morphology up to 12 months after surgery, compared to management with rehabilitation, due to the secondary (surgical) trauma to the knee.

OA rates are 4-6 x higher post-ACL tear – the dirty little secret is – that is with or without reconstruction!

2.  ACL reconstructive surgery reduces the risk of meniscus tears.

A common and incorrect belief. Some studies and reviews have concluded otherwise, but they have used inappropriate research designs. They are retrospective reviews of surgeons’ records, comparing people who present soon after surgery with people who have presented months or years after injury who could have had no rehab, unknown rehab or multiple cases of instability. Only three systematic reviews have used purely clinical trials in the review, which found no relation between the timing of the surgery and the risk of meniscal injury.

ACL rupture + no surgery ≠ more meniscus tears

3.  People cannot return to pivoting sports without an ACL reconstruction.

A soon-to-be-published systematic review by one of the world’s leading experts in ACL, Stephanie Filbay, found no difference in return to sport rates or activity level between people who had reconstruction compared to rehab alone. Even though many people who chose rehabilitation alone were encouraged not to return to high-level sports, the rates were the same despite this advice.

You can return to sport with or wothout an ACL.

4.  Fully ruptured ACLs cannot heal.

False, false, false! We were taught at university that ACLs could not heal because they are inside the joint capsule, and the ends get bathed in synovial fluid, and they can’t heal. However, in the KANON trial, healing rates were greater than 50%. Furthermore, in the soon-to-be-released Cross bracing protocol, they are showing healing rates of over 90%.

We all have some Wolverine powers

5.  Open Chain Knee Extensions Should Not Be Performed in the First four weeks post-op.

Many people recommend avoiding knee extensions and other open-chain exercises post-op, but studies developed these beliefs with poor methodology. Studies also show that it is impossible to activate the quads adequately with closed-chain exercises. So not only are they safe, they are essential.

Leg extensions are the best way to straighten quadriceps

So with this new knowledge, a significant shift is needed in the current method of management of ACLs. A big start is that people should only have surgery after 12 weeks post-injury. Early surgery for ACL ruptures should only be done in people with extenuating circumstances. The 12 weeks should be used to strengthen the knee, and even if the patient decides to have surgery, their knee will be much more robust and stable post-op than if the surgery was done soon after injury.



Primary surgery versus primary rehabilitation for treating anterior cruciate ligament injuries: a systematic living review and meta-analysis

Delaying ACL reconstruction and treating with exercise therapy alone may alter prognostic factors for 5-year outcome: an exploratory analysis of the KANON trial

Lower extremity performance following ACL rehabilitation in the KANON-trial: impact of reconstruction and predictive value at 2 and 5 years

Who’s afraid of the Big Bad Wolf? Open Chain Exercises After ACL Reconstruction