ACL healing background information
Historically, it has been accepted by health professionals that a ruptured ACL has a limited healing capacity due to a limited blood supply to heal each end of the ruptured ligament.
This has led to an increased push for surgical management of an ACL rupture.
In recent years, research has highlighted other avenues for ACL rupture rehabilitation which provide an alternative to surgery.
For this blog, we will be discussing:
Non-operative management of ACL tears/ruptures
Delayed rehabilitation of ACL rehabilitation
Injury prevention / Risk reduction of ACL tears
*Disclaimer*
Please note that although we are discussing and presenting research around the above areas of ACL recovery we are not discounting the option of ACL-Surgery, we are simply outlining alternatives to rehabilitation that may be more appropriate for some more than others.
Do not use this blog as a decision-making tool, please consult with your health professional before making choices about ACL recovery.
Non-Operative management
Study #1. Healing of acute anterior cruciate ligament rupture on MRI and outcomes following non-surgical management with the Cross Bracing Protocol (Filbay, Dowsett, Chaker Jomaa, et al - 2023)
This study has rocked the physiotherapy and health practitioner world by investigating a new ‘Cross-Bracing Protocol’ as a form of Non-surgical management of acute ACL rupture.
The findings of this study displayed that 90% of patients in this trial had signs of ACL healing on MRI after 3 months. This is a massive development as it was a common belief between researchers and clinicians that the ACL has a limited healing capacity and because of this has shaped common management strategies of an ACL rupture.
They also discovered that more ACL healing on a 3- 3-month MRI was associated with better knee function and Quality of life, less passive knee laxity, and a higher return-to-sport rate This landmark trial will form the basis of exciting future research in the non-operative management of ACL ruptures and will be one to follow closely.
Study #2. Time for a Different Approach to Anterior Cruciate Ligament Injuries: Educate and Create Realistic Expectations (Zadro & Pappas, 2019)
This study looks at the expectations and education around ACL injuries and their recovery.
This study ties in with the common historical thought that surgery was the only way to ‘fix’ an injury ACL. We now know and will continue to learn about other recovery strategies for ACL repair.
There is now strong evidence that conservative management of ACL injuries does not result in inferior outcomes compared to surgery however in the public eye surgery is the only option.
A randomised controlled trial involving 121 patients compared early ACL surgery to conservative management (with an option for delayed surgery) and found no between-group differences in knee symptoms, function, quality of life, sports participation, or radiographic knee osteoarthritis at 5-year follow-up
This is one of many studies comparing Surgery to Conservative management that has similar outcomes to each other.
Study #3. Delaying ACL reconstruction and treating with exercise therapy alone may alter prognostic factors for 5-year outcome: an exploratory analysis of the KANON trial (Filbay, et al - 2017)
This study is part of the KANON trial mentioned in study #1. They investigated the longer-term outcomes (5 years) when comparing early ACL surgery to non-surgical interventions
Further analysis by Filbay et al (2017) of the KANON trial showed patients who received early ACL surgery were prognostically worse across multiple domains compared to the non-surgical and delayed surgical arms, suffering a ‘second trauma’ due to the surgical drilling through intra-
articular structures, a period of prolonged joint inflammation, and altered weight-bearing
This is significant when coupled with Study #2 as if there was no difference in 5-year follow-up outcomes with many different factors but there were factors following surgery which made surgery prognostically worse then this may guide a particular patient to conservative treatment
ACL Injury-Prevention / Risk Reduction in Sport
There is a plethora of research on risk factors, injury prevention protocols, and injury risk reduction in sports, in particular ACL injuries. The ACL is often targeted in this research due to the longevity of the injury.
Now we certainly aren’t saying that we can prevent ACL injuries but we can help reduce the risk of them occuring in the first place. Tearing the ACL is usually a result of planting a foot and then rotating causing a torsional force on the ACL causing it to tear. If this is a common cause, then it can often form the basis of our injury prevention training this movement/action allows our body to become more familiar with it and therefore not as great a stress on the ligament. The process is comfortably more technical than than explanation but for the sake of time it gives a nice broad overview Let's look at some Injury prevention research
Study #4. Non-contact ACL injuries in female athletes: an International Olympic Committee current concepts statement (Renstrom P, Ljungqvist A, Arendt E, et al - 2008)
This study investigates the injury rates of female athletes and what they found was a higher rate of ACL incidence in females compared to males
The risk factors highlighted for injuring the ACL were
Weakness in hip Abduction
Increased knee valgus forces (knee caving in)
Having greater knee valgus force can put more strain on the ACL
Limiting the valgus position of the knee during a single-leg landing could reduce strain on the ACL and in turn reduce the number of noncontact ACL injuries. Our results suggest that women land in greater knee valgus than men (Russell, et al - 2008)
These particular areas should be targeted in a Non-contact ACL injury prevention program in females (as well as males).
Study #5. Preventing Australian football injuries with a targeted neuromuscular control exercise program: comparative injury rates from a training intervention delivered in a clustered randomized controlled trial (Finch, Twomey et al - 2016)
This study investigated the effects of neuromuscular control training on the effects of injury incidence.
They had a pool of 1500 footballers which they split into Regular training vs Neuromuscular control training (Balance / Change of Direction / Landing) which was completed twice per week. What they found was quite significant. Total injuries Regular training = 438 Neuromuscular training = 335 Knee Injuries Regular = 60
Neuromuscular = 32 Neuromuscular training results
Reduced knee injuries by 50%
Lower limb injuries were reduced by 22%
These are significant findings in the AFL population which are documented to have a high rate of ACL tears in sport due to the 360-degree nature of the sport. For professional and local football clubs this should be a non-negotiable when it comes to designing a training program.
Please contact one of our physiotherapists if this is something that we can help your club with as it clearly works!
Summary
The point of this blog was to highlight some alternative options to ACL recovery as well as having an ACL reconstruction as part of our potential treatment planning.
This is an exciting space currently in physiotherapy research and we will continue to apply evidenced-based practice here at High Line Active for your ACL concerns.
We pride ourselves here at High Line Active to help provide for the Richmond community and its surrounds to provide the best care we can in this space. We think that recovery is fantastic but we are also passionate about reducing the risk of the same injury happening again. Injury prevention, particularly in sports, we believe is an undervalued area of sports medicine. You don’t need to be an elite athlete to apply the principles of injury prevention so please reach out if you or your club/team would like more information on creating an injury prevention protocol.
This summary displayed just a small section of the research around this ACL recovery so please contact us if you have more questions about this as stated in our disclaimer, please do not use this summary to purely decide on your treatment, discuss the options first with your surgeon or your High Line Active Physiotherapist
References 1. Filbay SR, Dowsett M, Chaker Jomaa M, et alHealing of acute anterior cruciate ligament rupture on MRI and outcomes following non-surgical management with the Cross Bracing ProtocolBritish Journal of Sports Medicine Published Online First: 14 June 2023. doi: 10.1136/bjsports-2023-106931
2. Zadro JR, Pappas E. Time for a Different Approach to Anterior Cruciate Ligament Injuries: Educate and Create Realistic Expectations. Sports Med. 2019 Mar;49(3):357-363. doi: 10.1007/s40279-018-0995-0. PMID: 30284693.
3. Filbay SR, Roos EM, Frobell RB, Roemer F, Ranstam J, Lohmander LS. Delaying ACL reconstruction and treating with exercise therapy alone may alter prognostic factors for 5-year outcome: an exploratory analysis of the KANON trial. Br J Sports Med. 2017 Nov;51(22):1622-1629. doi: 10.1136/bjsports-2016-097124. Epub 2017 May 17. PMID: 28515057; PMCID: PMC5754848.
4. Renstrom P, Ljungqvist A, Arendt E, et alNon-contact ACL injuries in female athletes: an International Olympic Committee current concepts statementBritish Journal of Sports Medicine 2008;42:394-412
5. Russell KA, Palmieri RM, Zinder SM, Ingersoll CD. Sex differences in valgus knee angle during a single-leg drop jump. J Athl Train. 2006 Apr-Jun;41(2):166-71. PMID: 16791301; PMCID: PMC1472649.
6. Finch CF, Twomey DM, Fortington LV, Doyle TL, Elliott BC, Akram M, Lloyd DG. Preventing Australian football injuries with a targeted neuromuscular control exercise programme: comparative injury rates from a training intervention delivered in a clustered randomised controlled trial. Inj Prev. 2016 Apr;22(2):123-8. doi: 10.1136/injuryprev-2015-041667. Epub 2015 Sep 23. PMID: 26399611; PMCID: PMC4819647.