Reconstructive ACL surgery: Is it beneficial?

Posted on July 6, 2018

(Last Updated On: July 6, 2018)

We’ve seen some people tear their anterior cruciate ligament and are fine. They don’t need to reduce their activity level, they’re not in pain, they don’t get arthritis, etc. It’s as if they have no need for an ACL.

These are the exceptions though. The outliers. By definition, most of us do not fit in this category. The rest of us are left with the option of possible reconstructive surgery. Before we decide to get cut open, we should first ask, is reconstructive ACL surgery actually beneficial? Or are we just screwed regardless? Let’s find out.

In deciding whether or not ACL surgery is beneficial I’m going to dissect a bunch of studies comparing the outcomes of those who have had surgery versus those who chose the conservative route, or non-operative treatment.

Within those two groups we’re going to look at who returns to their preinjury levels better, what are the long-term implications of either option e.g. rates of arthritis, quality of life, who is more satisfied with their treatment, and so on.

I want to first start off with a primer on ACL research. To be blunt, sorting through the information on this topic is an absolute mind and clusterfuck. One study declares such and such related to the ACL, the next study declares the opposite. Numerous studies aren’t well done. Barely any studies are randomized (the gold standard for research studies). Most are surveys or retrospective studies, which open themselves to all types of bias. (If you’re looking back on something and you’re thinking you’re going to find A, you’re more likely to find A even if B is more present.)

When it comes to surgery all sorts of ethical issues come into play: if you believe a surgery is beneficial, is it ethical for you to delay someone the ability to have that surgery in order to compare their outcome to someone who has the surgery?

When you read the studies and some of them end with quotes to the tune of, “We have as much debate over this surgery as we did 50 years ago” and you consider

1) The amount of time, money and effort put into this area and

2) Over 100,000 reconstructive ACL surgeries are done each year,

this is, as one doctor put it, “A sad state of affairs.”

My Dad has always sad medicine is more art than science. In no place have I come across does this seem truer than in ACL reconstruction. I have spent MONTHS trying to figure out what the hell to do with my own leg.

If you’ve tried to read through the information on this topic hopefully I will be able to present a clearer picture of what’s going on. If you haven’t, hopefully this series will help you form your own decision on what to do with your leg.

The studies I will be primarily talking about are the few randomized controlled trials out there. It’s been estimated up to 80% of non-randomized studies are forming false conclusions. While I won’t completely ignore these studies, they shouldn’t be what you, or I, take into strongest consideration.

Lastly, I’m not going to cite every single study I’ve read. I think that will just clutter and confuse this whole thing. I’m going to tie all my points together with the best, most recent study at the end. So if you’re looking for specific data it’ll be towards the end.

Returning to preinjury levels 

Much like all the answers in life, when it comes to determining if ACL surgery is beneficial in returning you to your preinjury activity levels, the answer is, “It depends.”

The primary factor is what were your preinjury activity levels to begin with? Are you a professional athlete? If you are, that still doesn’t mean much. What also matters is the type of preinjury activity. You might be a professional…curler…that’s not the same type of activity as a professional football player.

When deciding if ACL surgery will help you return to your preinjury activity levels you need to ask yourself

1) What type of activity are you looking to return to?

2) What level of activity are you looking to return to?

Playing racquetball, a sport involving stopping and going, pivoting, etc. with your son or daughter once a week is not the same as playing in a competitive league twice a week.

When it comes to returning to high levels of activity, in the types of activity that require a lot of pivoting, stop and go like movements (basketball, football, soccer), there is decent evidence in favor of getting the surgery. While if you look at those who are looking to achieve a moderate activity level or below, there is very, very little evidence surgery will leave you better off than conservative treatment.

There is an activity level commonly looked at called the Tegner activity scale:

Level 10 – Competitive sports- soccer, football, rugby (national elite)

Level 9 – Competitive sports- soccer, football, rugby (lower divisions), ice hockey, wrestling, gymnastics, basketball

Level 8 – Competitive sports- racquetball or bandy, squash or badminton, track and field athletics (jumping, etc.), down-hill skiing

Level 7 – Competitive sports- tennis, running, motorcars speedway, handball
Recreational sports- soccer, football, rugby, bandy, ice hockey, basketball, squash, racquetball, running

Level 6 – Recreational sports- tennis and badminton, handball, racquetball, down-hill skiing, jogging at least 5 times per week

Level 5 – Work- heavy labor (construction, etc.)
Competitive sports- cycling, cross-country skiing,
Recreational sports- jogging on uneven ground at least twice weekly

Level 4 – Work – moderately heavy labor (e.g. truck driving, etc.)

Level 3 – Work – light labor (nursing, etc.)

Level 2 – Work – light labor
Walking on uneven ground possible, but impossible to back pack or hike

Level 1 – Work – sedentary (secretarial, etc.) 

Level 0 – Sick leave or disability pension because of knee problems

We’re talking about surgery for those at about a 7 and above, and possible conservative treatment for those 6 and below.

Now I really don’t know where the majority of people are going to be on this scale. ACL injuries seem to occur the most in younger males who are more likely to be in the upper levels of this scale. If you’re looking to return to those higher levels, surgery is a good option. Although, it is not necessary for you to return to those high levels (more on this later). If you’re someone who has never been above a 6, and you’re sure you never want to be, it’s going to be hard to justify surgery after I get through all this.

Long-term implications

An oft-cited reason for “needing” ACL surgery is to diminish your chances of getting arthritis. Without the ACL, it’s commonly said your rates of arthritis go up. So, if you’re interested in the long-term well being of your knee you should get the surgery.

And this is very important. While I love playing sports at a high level, I’m much more concerned with being able to walk in 10 or 20 years. But, and this is a big but, there is not one single randomized controlled trial showing people with reconstructed ACLs are better off in the long-term than non-operated people. In fact, many retrospective studies show those who get the surgery have a greater chance of arthritis.

Coinciding with my primer on ACL research, there is a plethora of confounding variables with these studies. A lot of times the people who opt for surgery are worse off to begin with. Maybe they had a more serious injury than their counterparts. Well, they might not be comparable to a non-operated group. Another issue: Those who get the surgery may be more likely to return to a higher level of activity, and those who stay in high levels of activity are more likely to get arthritis. Perhaps it’s not the surgery that predisposes them to arthritis but it’s the fact they are able to return to a higher level of play? The list of issues goes on.

Hell, there is a whole roundtable of physicians debating this topic. The biggest take home point is what one physician said,

“I do not believe we can inform patients that the indication on ACL reconstruction is based on arthritis prevention.”

I’ll speak more on this when I tie things together later, but for right now decreasing rates of arthritis does not appear to be a benefit of this surgery.

Tying things together

Let’s look at the nitty gritty of the best, most recent study. This study actually caused quite a stir when it came out last year due to its seemingly controversial results.

A Randomized Trial of Treatment for Acute Anterior Cruciate Ligament Tears.

As you can see, and I wouldn’t be surprised if the authors did this on purpose, “Randomized trial” is in the title. This is the best study I have found on ACL reconstruction. There have been some other studies similar to this one but they were conducted at least 20 years ago. (They did find similar results though.)

As I mentioned, ethical reasons are a big issue with doing a randomized trial for ACL reconstruction. The authors sort of got around this. They designated one group for surgery and gave another group the option of surgery down the road if they were not satisfied with their conservative treatment. This opposed to telling them they had to stay with the conservative route for X amount of time.

The two groups were followed for two years and were compared on their activity level, quality of life, and other various ways of assessing the knee.

After two years, there was very little difference between the two groups. The group who did not have surgery fared just about as well as the group who did have surgery.

The group who had surgery was about 10-15% more active on average than the non-operated group. (Although 25% of those who didn’t have surgery returned to an 8 on the Tegner scale!) Their quality of life related to their knee was about 7% better. And there was no difference in the amount of pain each group was in. So far we aren’t making a very strong case for getting this surgery.

That is until we start looking very closely at the data of this study. First, 40% of those put in the non-operative group decided to have surgery during the two year follow-up. This was presumably due to being unhappy with their quality of life and whatnot. There is a good chance that number would grow in the subsequent 3rd, 4th… ,10th year and so on.

Perhaps most importantly, and you will only see this if you look at the supplementary appendix (which isn’t in the PDF for some reason), 10% of those operated on had to have a follow up meniscus surgery while 28% of those not operated on had to. Nearly a 20% difference. And more importantly, it appears if you do not have the surgery you have about a 30% chance of tearing your meniscus compared to a 10% risk if you have the surgery.

The authors dismiss this rather quickly stating that those who were not treated for the ACL tear were more likely to not be treated for a meniscus tear either. Unless the tear was large. So that’s why they had a much higher rate of follow up meniscus surgeries.

I’m not sure I’m buying that logic. In the very least not getting the surgery made these people more likely to have a meniscus that got bad enough warranting surgery. Either they’re more susceptible to a tear or they are more susceptible to making a small tear a problematic tear. We also don’t know how many of them will have tears in their 3rd, 4th, …or 10th year post-injury.

Also, while not to a great extent, the reconstructed group was more active after two years, which is going to make them more susceptible to a meniscal issue. I think the fact that they are more active makes up for the fact that those not treated for the ACL tear were likely to not be treated for the meniscus.

I told you this was a mind-fuck.

Next, unfortunately this study only started (now) 3 years ago and therefore only had a two year follow up. Two years really isn’t a long enough to know whether or not the surgery would benefit arthritis rates. I can only say that logically it makes sense it would. If you’re more likely to tear your meniscus you are more likely to have arthritis. However, again, these people could make up for that factor by reducing their activity levels. Bringing us to one last issue with this study…

It’s not stratified for activity. Meaning we do not know what happened to those who returned to certain levels of activity. Maybe those who didn’t have ACL surgery and tore their meniscus tried to come back to too high a level of activity? And those who stayed a moderate level were fine?

-> This study: Non-operative management of anterior cruciate ligament injuries in the general population found in the general population there was no differences in those who were reconstructed versus those who were not.  Including rates of meniscal tear. They found absolutely no benefit in having the surgery for people whose highest level of activity is recreational. But it wasn’t randomized.

This is a common theme in the few well done studies: When activity levels aren’t controlled those who do not have the surgery are more likely to tear their meniscus. The numbers jump around but about 20% more likely is about right (like this study says).

In the end, in my mind this study ties all other studies on ACL surgery together. Other than a select few looking to attain that 8, 9 or 10 on the activity scale, ACL surgery does not guarantee you’ll be more active than if you don’t have the surgery. It actually doesn’t guarantee you’ll be that active if you get the surgery either. It just makes you a bit more likely to get to that level.

Again, regardless of treatment, 25% of each group got to an 8 on the activity scale. Both groups had people who were able to still be VERY active. So, even for some the surgery makes no difference in this regard.

In all other measures, pain, symptoms, quality of life, arthritis, whatever. The surgery makes minimal if any difference either.

The one thing the surgery seems to do is benefit those who are looking to partake in high impact sports; at a very competitive level, by minimizing their risk for further damaging their knee. That is it.

So there is some benefit to reconstructive ACL surgery. But that’s actually not the most important question. The true question you need to ask is…Is it worth it? That’s what I’ll talk about in the next post.



These aren’t all the studies but they are some of the best ones.

Studies showing no difference in arthritis. Remember there are no randomized trials for this category:

  • Ten year follow-up study comparing conservative versus operative treatment of anterior cruciate ligament ruptures. A matched-pair analysis of high level athletes.
  • Prevalence of tibiofemoral osteoarthritis 15 years after nonoeprative treatment of anterior ligament injury: a prospective cohort study. 

Studies showing reconstructed patients return have better rates of returning to the highest levels of activity:

  • Operative versus Non-Operative Treatment of Recent Injuries to the Ligaments of the Knee
  • Surgical or Non-Surgical Treatment of Acute Rupture of the Anterior Cruciate Ligament

Studies showing minimal if any differences in rates of return to activity:

  • Non-operative management of anterior cruciate ligament injuries in the general population (This is the best study done on more of your typical, non-extremely active, recreational athlete. There was basically 0 benefit found for these people having surgery. Including no difference in meniscal tears.)

Studies showing higher rates of meniscus tear in non-reconstructed patients:

  • Operative versus Non-Operative Treatment of Recent Injuries to the Ligaments of the Knee
  •  Surgical or Non-Surgical Treatment of Acute Rupture of the Anterior Cruciate Ligament
  • A Randomized Trial of Treatment for Acute Anterior Cruciate Ligament Tears (The best study.)
  • Ten year follow-up study comparing conservative versus operative treatment of anterior cruciate ligament ruptures. A matched-pair analysis of high level athletes.


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