ACL - Surgery or Physio?
There are a lot of conflicting opinions on Anterior Cruciate Ligament (ACL) tear treatment options. This makes it difficult for individuals to know what to ask for or even have a good quality shared decision-making approach to their treatment with their healthcare professional.
The evidence base doesn't make it any clearer either with no NICE guidance and a lot of outdated studies that are conflicting in terms of whether you should have surgery first or if you should try a conservative management approach first. The British Orthopaedic Association has published guidelines but in my opinion, are fairly lacking on when conservative management should be considered over surgical management with the phrase 'Non-operative and operative options should be discussed. The benefits, limitations, and likely outcomes of each should be discussed and recorded' however the benefits, limitations, and likely outcomes of conservative management are not discussed in the guidance.
It's your patient and you want to get it right for them or at least help guide them through the options or if you are a patient reading this it's your body and you want to get it right!
I want to demystify ACL treatment and try to explain why there are so many conflicting viewpoints and hopefully show that this isn't a bad thing... let me explain.
Conservative Treatment
So, what exactly is conservative treatment referring to? There are various definitions but, in this article, conservative treatment is anything that isn't surgery. I would like to use the term 'non-surgical treatment' but seen as 'conservative treatment' is used more commonly it will be used here to avoid confusion.
Generally, for an ACL tear conservative treatment is Physiotherapy. This will normally be exercise-based and involve a mixture of exercises for both regaining the full range of movement in the knee and strengthening your knee. Range of movement simply refers to your ability to bend and straighten your knee and we want to get this as back to your 'normal' as possible. Same with strength - generally ACL tears will make your knee feel weak and unstable and we want to combat this by strengthening and getting the hamstrings to take over some of the stability role from this ligament which is damaged.
I'm a physio therefore I must be saying this approach is the best? Well not exactly...
A physiotherapy-based approach will be a really good option for some people and not the best option for others.
Who does this work best for? To put it in simple terms it's the patients who can't have surgery, don't want to have surgery or those who have limited instability, symptoms or no other knee structures involved.
Therefore, a basic list of indications for a purely conservative management approach would be:
- Patients who have comorbidities that make surgery too risky/not an option
- The elderly or people for whom surgery is unlikely to be successful
- Patients who, with a shared decision-making approach, still wish to avoid any sort of surgery
- Patients who are less active and therefore surgery risks outweigh any benefit
- Patients who would struggle to follow a rehab regime post-surgery (either due to this being too difficult physically or who are unable to participate for any other reason)
- Patients who are 'copers' or 'adapters' - this means those who have limited symptoms or those who can give up those sports that cause the symptoms of instability (adapt to the situation)
It is important to reiterate here though that the decision for surgery or not is unlikely to be a Physio decision (unless you note clear comorbidities or the patient is very against surgery) and much more likely to be a decision undertaken from a consultant-led clinic and then the patient back to you for conservative management approach.
I say this as the current British Orthopaedic Association guidelines recommend early surgery over rehab first and studies do report a poorer outcome if conservative management is tried, and this fails, and the patient needs to go on to have surgical intervention.
This is being challenged by a systematic review in 2022 which found that there is no difference between primary surgical intervention and rehab first with subsequent surgical intervention. However, there are a lot of low-quality studies included in the analysis so I feel hesitant to recommend this approach especially given a consensus statement in 2021 and the current BOA guidelines both show that active individuals should be offered early surgery if possible.
Surgery
The surgery is typically performed arthroscopically (through small incisions to allow instruments into the knee) rather than through a larger open incision. The knee is examined under anaesthetic also to see if anything further needs to be performed such as a repair of the meniscus (cartilage pads that sit in the knee) as other structures can be damaged when you sustain an ACL tear.
A graft is used to replace the damaged tissue and this is generally removed (harvested) from elsewhere around the knee. The site will depend on the surgeon and the state of the other tissues so that the correct type is selected. Common sites are at the front of the knee (patellofemoral tendon) back of the thigh (hamstring tendon) and front of the thigh (quadriceps tendon).
Generally, younger patients will have a graft made out of their own tissue (like above) however older patients and patients in whom this isn't possible will have a transplanted graft (allograft) used instead.
Again, the above are just general terms - surgeons will discuss all of this with the patient and through shared decision-making will make the best choice with the patient which will give the best outcome.
So why might a patient opt for surgery?
Well, the biggest factor with ACL injuries is still that they mainly occur in young, active, sporty individuals. These individuals have a high drive to get back to their sport and if there is instability at the knee this will often be a high driving force behind having this stabilised, as an unstable knee often means they are unable to return to their sport.
A basic list of situations in which surgery is recommended to a patient over conservative management tends to be:
- In cases where a repairable meniscal tear is present - especially a meniscal tear that is symptomatic
- Cases where instability with affect quality of life - either general everyday life or through not being able to play sport
- Cases where conservative management fails - i.e. instability is still present
There is also some evidence that patients who undergo early reconstruction have a better outcome and even in a trial comparing good conservative management to early reconstruction there was a high amount of patients who ultimately opted for surgical intervention from the conservative management group due to instability still being present after a rehab first approach.
So where does physio come in?
Conservative Management
Here the main focus will be on knee stability. To achieve this a personalised and tailored exercise program with regular check-ins and outcome measures performed seems to be the best way forward.
As with most conservative management approaches there is not a lot of evidence in the literature for what is best in terms of the content for a good approach.
To give some basic guidance I would suggest the post-operative approach guidelines can be followed but with a lot less adherence to the timescales. However, this is going to be very patient dependant and as such a throughout assessment and 'treat the symptoms' approach is likely to be best.
Some good points to note:
- Personalise the approach to the patient
- Remember functional activities and sport-specific rehab
- Build strength in both quads and hamstrings to build knee stability
- Educate the patient - this won't be a quick few exercises and done - a long process is likely
- Re-assessment and outcome measures - great for you but also great to show the patient their progress!
Why have I been referred for Physio first?
In any ACL surgery, the work put in before surgery directly correlates with the outcome. More work and more muscle strength = better outcome. Therefore, often patients will be referred to physio before any surgery for Prehabilitation ('Prehab'). This is for a few reasons but the main are to improve quadriceps muscle strength and to improve knee range of movement.
This is there to improve the outcome post-surgery but also to allow time for the knee to settle. To have surgery we need to allow time for the knee swelling to reduce and also ensure a good range of knee movement, especially into knee extension. This is again to improve the outcome.
It also allows time for a thorough knee assessment both physical and with imaging to create the exact surgical plan as often other structures in the knee can be damaged and require intervention. In a study ACL tear only occurred in isolation 12% of the time. This again reinforces the point that personalised treatment planning is key.
The only cases where prehab tends to be routinely skipped is in patients who have a block to full knee extension from a repairable meniscal tear. In these patients, the surgical plan tends to be accelerated, but again this would be dependent on the individual and the surgeon.
A good set of general aims for Prehabilitation are:
- Improve knee extension to full range of movement (this is linked with less post-operative complications)
- Improve quadriceps strength (linked to better outcomes post-op)
- Preparation for post-surgery e.g. teaching crutch technique, going through what is expected in post-op rehab (no major evidence but common sense tells us that it is likely to help self-efficacy and also prepare the mindset of the patient for the op)
Post surgery?
Post-surgery rehab is very important to regain function post-reconstruction. Post ACL surgery rehab can take anything from 6-12 months on average with evidence for 9-12 months being optimal.
Rehabilitation will usually take place in phases and depending on the local area protocol these may be timed or function-based goals. There has been a move to more function-based goals as we are all different and rehab therefore needs to progress at different rates for different people.
Post-surgery rehab is extensive - especially when you take into account the return to sport and therefore this article won't go into detail about this here
Instead, here is a link to an extensive rehab protocol designed by the Royal Dutch Society of Physiotherapy which is evidence-based and peer-reviewed:
Conclusions and Takeaways
So remember at the start of this where I stated that the differing viewpoints weren't a bad thing? Well, the reason why is simple. Choice. Humans are all different and a one-size-fits-all approach is unlikely to ever be right for everyone. It is where as clinicians we come in. We are there to assess, guide and present the options to the patient.
For example, a patient who has played a lot of football sustains an ACL tear but was planning on giving this up anyway as he enjoys cycling may well opt for a conservative management approach as he has none of the potential surgical complications and can modify activity to live with some instability. However, that same person could have a meniscal tear which stops him from being able to achieve full knee extension and therefore actually ops for surgery.
Again, a teenage athlete who is on a Rugby scholarship and has been scouted by a team may well opt for surgery as she wants to play at the top level of her ability and continue playing for a long time. She might however see that others have done well with conservative management and opt for this instead given she has good access to high-quality rehabilitation at the club.
There is no right or wrong answer and this is where we as clinicians need to present all the options but also keep up-to-date ourselves with the evidence base. As you can see from the emergence of evidence in the last few years on this topic and the BOA guidelines being ready for their review cycle - things can change as we understand this area better.
Shared decision-making is about taking that evidence in the clinical context of the patient in front of you, presenting the options including the pros and cons and allowing them to make an informed decision on their care. Taking in the factors that are important to them including their return to sport makes this personalised. This should be the norm with patients and if you take nothing else away from this then it's still been worthwhile!