Does surgery for rupture of the anterior cruciate ligament improve outcomes?

When I started out as a young resident in orthopaedics in 2000, I was mesmerized by the beautiful arthroscopic images during anterior cruciate ligament surgery. These were enlarged and clearly projected intra-articular images of white femoral condyles, eventually with a reconstructed anterior cruciate ligament in between. This immediate operative resurrection of a torn structure and tangible restoration of a ligament with a stable feel to it, supported my wish to become an orthopaedic surgeon. As a young researcher, I was also attracted to researching this centrally located three-centimeter-long ligament as it has such a pivotal role in the homeostasis of the knee. 

In our earlier investigations, we looked at elite athletes 10 years after they had torn their anterior cruciate ligament. [1] To learn more, we looked at a control group of patients who had sustained an anterior cruciate ligament injury, were high-level athletes, but had not received an anterior cruciate ligament reconstruction. The reasons for not having surgery were numerous; some had been hesitant to receive surgery, some were advised to follow a rehabilitation track, some did not find the planning for the surgery to be fitting, and so on. What struck us most, when examining the non-operative group, was the laxity of the knee that was felt at the physical examination, but the laxity in this group did not mean that their knee was  unstable or that they were unable to participate in sport after 10 years.

The success of this specific group of high-level athletes living for a decade with a ruptured anterior cruciate ligament gave us an insight that nurturing nature, even with a torn structure, was not inherently worse than surgical repair. To operate or not that was our question.

So we decided to conduct some research into this. What better way than to choose the highest scientific quality research type than a randomized controlled trial. However, a computer block randomized clinical trial sounds to a surgeon, and also to most patients, like flipping a coin about whether to have surgery or not. This challenge was larger than we had ever imagined and required a shift in our thinking. Admitting to ourselves that science could not clearly distinguish between which patient needed reconstruction and which patient could be treated with rehabilitation was not an easy undertaking. Informing doctors and patients of the lack of available knowledge and the need for this trial was key.

We have now published a new research paper in The BMJ which finds that in patients with acute rupture of the ACL, those who underwent surgical reconstruction alone, compared with rehabilitation and optional surgical reconstruction, had significant improved clinical outcome, but the clinical importance is unclear. Taken alongside previous research from the Kanon trial, we have now reached a point in anterior cruciate ligament research, that we have shown that some patients do equally well with non-operative treatment. [2] The challenge lying ahead is predicting more accurately and more quickly which treatment fits which patient. 

We have started an innovative clinical randomized trial with cluster randomization to investigate shared decision making, supported by a treatment algorithm, to start scientifically based personalised anterior cruciate ligament treatment.

Duncan Meuffels is an associate professor and Sport Orthopaedic and Complex Knee Instability Surgeon, who is actively involved in research of the knee.

Max Reijman was trained as a physiotherapist and epidemiologist. He is an associate professor involved in cost-effectiveness studies in the field of orthopaedic surgery related interventions of musculoskeletal conditions.

Competing interests: see linked research paper.


  1. Meuffels DE, Favejee MM, Vissers MM, et al. Ten year follow-up study comparing conservative versus operative treatment of anterior cruciate ligament ruptures. A matched-pair analysis of high level athletes. Br J Sports Med 2009;43:347–51.
  2. Frobell RB, Roos HP, Roos EM, Roemer FW, Ranstam J, Lohmander LS. Treatment for acute anterior cruciate ligament tear: five year outcome of randomised trial. BMJ 2013;346:f232. doi: 10.1136/bmj.f232 pmid: 23349407