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ACL Injury Decision Making: Is the knife always needed?

Updated: Oct 30, 2023

First Published December 2021.

Last updated: August 2023

A guide to surgical vs non-surgical decision making following ACL injury.

It may surprise some, but not all Anterior Cruciate Ligament (ACL) injuries require reconstructive surgery. Many people can return to high-level activities and cope well without an ACL. The decision of which option to go for can be difficult. In this post, I share the key questions to ask yourself when considering whether ACL Reconstruction (ACLR) surgery is the right option for you.

This blog presents evidence-informed recommendations for athletes considering surgical versus non-surgical options to manage ACL injuries. Following a recent Instagram post on this topic, this blog expands on the topic and presents questions for clinicians and athletes to consider after injury.

Firstly, it's important to recognise that not all Anterior Cruciate Ligament (ACL) injuries require reconstructive surgery. Many people can return to high-level activities and cope well without an ACL. Whether you have the surgery or not, the rehabilitation journey can be lengthy.

If you have recently sustained an ACL injury, you may be told that you must have surgery to recover fully. It's becoming clear in the research that some people can do well with non-surgical approaches, however, the challenge remains in deciding who will likely respond well to non-surgical rehabilitation options. The research is not clear on who will respond well to non-surgical approaches, however there are some indicators of who is more likely to need surgery. Understanding these 'copers' versus 'non-copers' is perhaps the next frontier in ACL research.

My thinking on this has of course been shaped by the athletes I work with, but also by experts in the field like who regularly shares the evidence on this topic, and by high-level grapplers like @livia_giles who has competed at the highest level with an ACL-deficient knee.

Here are the key questions to ask yourself when weighing up if ACLR is the right option for you:

Q1 Is it a complete rupture of the ACL?

Research shows that partial ruptures may have the ability to heal, so non-surgical options are usually warranted, and certainly worth attempting as the primary treatment.

New research suggests that even full ruptures may have the ability to heal over time, so you may still benefit from non-surgical rehabilitation and reassessment after 3 months. If the joint remains stable without signs of further damage, then surgery may not be needed.

Q2 Is there any other damage to the knee?

'Simple' or 'uncomplicated' knee injuries that are limited to just the ACL are more likely to cope with non-surgical management.

Concurrent and significant damage to other aspects of the knee (e.g. meniscus, other ligaments, cartilage, or fractures) may complicate rehabilitation and increase the need for surgery.

Q3 is the knee unstable or giving way?

An ACL-deficient knee that feels stable demonstrates good function of other structures that support the knee. If these other structures are providing the required stability, surgery may not be required. Rehabilitation should focus on ensuring these structures can continue to support the knee during higher-level activities. If this describes your knee, then you should start exercise rehabilitation and reassess after 3 months.

If you are experiencing significant and ongoing instability (that is not responding to early rehabilitation), combined with functional impairments, this will increase the need for surgery to regain structural stability.

Q4 Is the knee function significantly impaired?

Your ability to complete normal activities without pain or instability is a key indicator that you may cope well with non-surgical management. If you are not experiencing significantly reduced function, surgery may not be required. If this describes your knee, you should start exercise rehabilitation and reassess after 3 months.

Important functional testing includes quad strength, single-leg hop testing, functional alignment tests, and assessment of the impact on normal activities of daily life. Large asymmetries and poor function may increase the need for surgery to improve long-term function. A rehab professional can guide you through these and support your decision making.

Q5 Are you aiming to return to high-demand activities?

Returning to low and medium-demand activities (sub-elite levels) can often be achieved with non-surgical management. If this describes your goals, it's likely that you may begin non-surgical rehabilitation and reassess after 3 months.

Although new research shows that athletes may be able to return to high-demand activities, these athletes may benefit from surgical consideration to provide the structural stability required to return to full function.

Sport and athlete-specific considerations are essential here.

Other considerations

Psychological readiness for surgery - Recovery from ACLR's is physically and mentally tough. Carefully consider the timing and commitment required to recover from this major surgery.

Preference and beliefs - the evidence doesn't strongly favour one option for all, so your preferences should always be taken into account.

Age - is a consideration, as ACLR’s are more commonly done in younger people who tend to be more active, but your future activity plans are more important than your age.

Self-healing possibility - new research suggests that spontaneous self-healing of the ligament after a complete rupture is possible. It's not well understood who may be a good candidate and more likely for this to occur yet, but if you have a mid-portion tear, with the ends of the torn ligament in close proximity to each other, you may be more likely to experience self-healing. More on this on the blog here.

So, what are the options?

The decision of whether to undertake surgical options following ACL injuries is complex, with many factors to consider. The answers to any one of the above questions won't be enough to make the decisions on its own, but together, and in combination with your own preferences and health professional advice can help guide the decision making. Essentially, you'll need to make a decision on one of three options.

There are 3 options post-injury:

👉Option A - Non-surgical management focused on rehabilitation as the first-line treatment (followed by ACLR and rehab if functional instability develops).

👉Option B - Early ACL reconstruction as the first-line treatment, followed by post-surgical rehabilitation.

👉Option C - ACL healing protocol and non-surgical rehabilitation - including the Cross bracing protocol (option for delayed surgery if no healing is evident and functional instability develops).

It's a tough decision for many, so I recommend that you seek professional advice and aim to work with rehabilitation specialists who understand your sport and are experienced in managing this type of rehabilitation.

I wish you all the best with your rehabilitation journey. Don't hesitate to reach out should you have any questions.



  • Ardern CL, Ekås GR, Grindem H, et al 2018 International Olympic Committee consensus statement on prevention, diagnosis and management of paediatric anterior cruciate ligament (ACL) injuries British Journal of Sports Medicine 2018;52:422-438.

  • Filbay, S. R. and Grindem, H. (2019) ‘Evidence-based recommendations for the management of anterior cruciate ligament (ACL) rupture’, Best Practice and Research: Clinical Rheumatology. Elsevier Ltd, 33(1), pp. 33–47. doi: 10.1016/j.berh.2019.01.018.

  • Paterno, M. V. (2017) ‘Non-operative Care of the Patient with an ACL-Deficient Knee’, Current Reviews in Musculoskeletal Medicine. Current Reviews in Musculoskeletal Medicine, 10(3), pp. 322–327. doi: 10.1007/s12178-017-9431-6.

  • Filbay SR, Dowsett M, Chaker Jomaa M, et al. Healing of acute anterior cruciate ligament rupture on MRI and outcomes following non-surgical management with the Cross Bracing Protocol British Journal of Sports Medicine Published Online First: 14 June 2023. doi: 10.1136/bjsports-2023-106931


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