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Do I need to have an ACL reconstruction?

Nov 3, 2020 | Knee, Patient Tips

You’ve injured your knee, and have got the news you’ve torn your Anterior Cruciate Ligament (ACL). It’s distressing news to receive, and no doubt there are a lot of thoughts running through your head.

One of the most important decisions is whether to go down the surgical route for treatment, or to trial non-operative treatment. However, it seems that everyone has an ‘expert opinion’ on this topic these days, so how do you decide what’s right for you?

Every ACL injury is unique

It’s important to remember that each knee injury is unique. Many patients often say they’ve ‘torn their ACL’, or need a ‘knee reconstruction’, but it’s important to differentiate between isolated ACL rupture or an ACL rupture with more complex injuries involving other structures inside the knee. At least 50% of ACL injuries will involve damage to other structures– these include the menisci, cartilage, bones and other stabilising ligaments in the knee. When more of these structures are damaged, the injury becomes more complex. Surgeons to recommend surgical treatment of complex injuries to prevent ongoing damage to the knee.

When is ACL reconstruction recommended?

A definitive recommendation can only be given once a full assessment has been done, including talking to the patient, assessing their individual needs, examining their knee and reviewing up-to-date imaging (MRI).

There are times where ACL reconstruction (knee reconstruction) would definitely be recommended, as opposed to a trial of non-operative surgery.

These include –

  • Locked knees: bucket handle tears of the meniscus require early surgical intervention to prevent degeneration of the knee and get it moving again.
  • Large, repairable meniscal tears or cartilage damage
  • Continued instability, pain or swelling despite rehabilitation
  • Knees which have had more than 1 ligament injured (multi-ligament knee injuries)
  • Patients engaging in high-demanf sports who wish to continue their chosen sport

Some studies suggest a trend towards better functional results after ACL reconstruction with lower rates of secondary meniscal injury. Still, it’s important to weigh up the risks and benefits of surgery for each individual, as some patients may become functional with rehabilitation alone. (1,2)

When is non-surgical treatment a good idea?

In some cases, non-surgical treatment can yield good results for people who have sustained an ACL rupture. Again, each case is unique, and it’s important to understand the specific needs of the patient. The ideal candidates for non-surgical treatment are those patients who:

  • Have no other injury in the knee: ie no meniscal, cartilage, or other ligamentous injury
  • Do not get continuing instability symptoms, knee swelling or pain
  • Participate in a comprehensive rehab program
  • Are not playing high demand sports, although this point is contentious!
  • Patients who are older, or who demand less of their knee (3)
Is non-surgical treatment successful?

In general, not having surgery will have no bearing on whether the ACL will ‘heal’ or not. Most complete ACL ruptures will not heal, however there are occasions when some healing of the ligament can take place or the ligament can stick down to structures next to it (most commonly the PCL). In these cases, patients may feel ‘some’ stability from their knee, even though it may not be completely normal.

Many patients who initially trial non-operative treatment will have surgery at a later date. In Frobel’s study, comparing surgery and physiotherapy to physiotherapy alone, 39% of patients within 2 years, and 51% by 5 years, who were initially treated non-operatively chose to have surgery within 5 years of their injury as they were unsatisfied with their knee function. It’s important to note that patients enrolled in this study were ideal non-operative candidates – no significant meniscal tears, single ligament injury only and no elite level athletes. (4,5)

When is the best time to have surgery?

For most cases, the timing of surgery is up to you! It’s important not to rush in to surgery. The focus immediately after your injury is to reduce the swelling in the knee and regain normal range of motion of the knee. To safely have surgery and optimise your post-operative results, it’s important to be comfortable with your knee prior to having surgery. You should be able to walk comfortably, without crutches or a walking aid, and be able to straighten the knee fully. Ideally, you’ve commenced some ‘prehab’ on your knee with an experienced physiotherapist who has an interest in ACL injury treatment. This will make for a smoother post-operative recovery!

There are occasions when surgery should happen early (or straight away!). The most common reason for this is a locked knee, where injury to another structure in the knee is blocking the knee from moving. Not uncommonly, a bucket handle tear of the meniscus will cause this, with the patient being unable to straighten their knee and will have a feeling of the knee being ‘blocked’ when trying to extend. In this, or similar, situations, surgery needs to be expedited to relieve the knee of the obstruction and repair the meniscus in addition to the ACL reconstruction.

Does surgery protect my knee against further damage?

This is a very difficult question to answer! Karikis et al found a decreased rate of meniscus surgeries in patients undergoing early surgery versus delayed surgery, and a subsequent increase risk of progression to knee replacement with non-operative treatment. However, the answer is not so simple, with other studies (Frobell) finding that in certain circumstances, without meniscal damage, the results of both forms of treatment can yield similar results in the short- to mid-term. What is known, is that secondary osteoarthritis is significantly reduced in knees without meniscal damage. Preserving meniscal function, or repairing torn meniscus, is important to optimise knee function and longevity. If you are having instability episodes and swelling, you are doing damage to your knee! (2,5,6,7,8)

Making an informed decision

In summary, both surgical and non-surgical treatment options exist when managing ACL injury. Decisions regarding surgery are complex, and it’s recommended that any patient with a suspected ACL injury undergoes an assessment by an orthopaedic specialist after obtaining an MRI to discuss the optimal course of treatment for them:

  • Be informed, each injury is specific and requires an individually tailored approach. Talk to your surgeon, sports physician, physiotherapist and general practitioner.
  • There are no shortcuts: both operative and non-operative treatments require a structured rehabilitation program to return to activity
  • Beware the unstable, swollen knee with repetitive instability episodes. This is causing more damage inside the joint!
  • Your knee has changed, it will take a long time to feel close to ‘normal’ again.
  • Prevention is better than cure!

If you would like to know more about the management of anterior cruciate ligament injuries, please download this flyer produced by Dr Ross Radic.

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  1. Krause et al. Operative Versus Conservative Treatment of Anterior Cruciate Ligament Rupture: A Systematic Review of Functional Improvement in Adults. Dtsch Arztebl Int 2018; 115(51-52): 855-862.
  2. Barenius et al. Quality of Life and Clinical Outcome After Anterior Cruciate Ligament Reconstruction Using Patella Tendon Graft or Quadrupled Semitendinosus Graft: An 8-Year Follow-up of a Randomized Controlled Trial. AJSM 2010; 38(8): 1533-1541.
  3. Paterno. Non-operative Care of the Patient with an ACL-Deficient Knee. Curr Rev Musculosketel Med 2017; 10(3): 322-327
  4. Frobell et al. A Randomized Trial of Treatment for Acute Anterior Cruciate Ligament Tears. NEJM 2010; 363(4): 331-42
  5. Frobell et al. Treatment for acute anterior cruciate ligament tear: five year outcome of randomised trail. BMJ 2013; 364:f232
  6. Karikis et al. The Long-Term Outcome after Early and Late Anterior Cruciate Ligament Reconstruction. Arthroscopy 2018; 34(6): 1907-1917
  7. Sanders et al. Is Anterior Cruciate Ligament Reconstruction Effective in Preventing Secondary Meniscal Tears and Osteoarthritis. AJSM 2016; 44(7): 1699-1707.
  8. Oiestad et al. Knee Osteoarthritis After ACL Injury: A Systematic Review. AJSM 2009; 37(7): 1434-43.