Why you shouldn’t bother with a non-orthopedist testing your ACL

Posted on April 10, 2015

(Last Updated On: March 27, 2016)

After I tore my anterior cruciate ligament, I fell on the ground and didn’t move for a few minutes. Eventually I walked off to the side of the field I was on, relaxed for maybe 30 minutes, then went to the bar with the guys I was playing flag football with. I didn’t feel great, but I had felt plenty worse.

The next day I couldn’t walk. I go to the ER and the physician tests my ACL, feels its solid, tells me to check in with an orthopedist in a few days if I’m still feeling symptoms. Great. ACL isn’t torn. This can’t be too bad.

The next day, two days after tearing the knee up, I work a 10 hour day. That’s ten hours of standing and walking. Again, didn’t feel great, but it was doable.

My symptoms are gone after a few days. After a week I’m back out on the field and my knee buckles on me. “Guess I’m not feeling as well as I thought.” I take some more time to heal up.

Months later I’m still having trouble. I go to an orthopedist and in about five seconds I’m told my ACL is torn. What the hell?

I’ve had my ACL tested by three non-orthopedists. One ER physician, one physical therapist, and one primary care physician. I eventually learned all three did the test wrong. Here is why you should never bother with the opinion of a non-ortho for this type of stuff.

They don’t have the sensory skills

Never mind doing the test properly, non-orthopedists don’t do these tests everyday. With the ACL, we’re talking about the anterior drawer and Lachman test.

lachman test can't quite see other hand

A Lachman is a slightly modified anterior drawer test. The gist of the tests are the same: You’re observing how much the tibia anteriorly translates. (White arrow above.) Like pulling a drawer forward. The anterior cruciate ligament, when intact, will prevent excessive anterior translation.

These tests are dealing with differences of millimeters, along with various perceptions, such as a “clunk” from the ACL engaging. It takes time to get this sense of feel down. Time and practice. Regular practice. Most orthopedists do this regularly. Most non-orthos do not.

Another thing to look out for is the hamstrings engaging. The anterior cruciate ligament helps prevent anterior translation of the tibia.

ACL Lachman with drawing and anterior translation

When the tibia is pulled into anterior translation, the ACL should engage and help pull the tibia back.

So do the hamstrings.

ACL lachman with hamstring line

Notice the similarities between the hamstrings and ACL. Similar line of pull, both have proximal tibial attachments, etc.

If the hamstrings fire during these tests they can give a false negative -your ACL is fine- even though the ACL isn’t there. (If you’re wondering if this is one way people can get by with no ACL, yes.) Especially if you’re just after the injury where likely everything is tense. Again, you need a good sense of feel for this. Feeling the hamstrings contract is much easier than dealing with the millimeters of the tibial translation, however,

You have to actually touch the hamstrings in order to know if they’re contracting

First way I’ve seen three people do this test wrong: They didn’t have one hand on my hamstrings while the other was pulling on the tibia.

This is good:

lachman test lateral view can see both

One hand on femur, so it can touch the hamstrings; other hand on tibia, so it can be pulled anteriorly.

lachman test superior view can see both hands

This is not:

anterior drawer test

With both hands on the tibia (last image above), you can’t feel if the hamstrings contract. Some will place the hands high enough on the tibia that they can feel the hamstrings somewhat, but it’s not the same as one hand under the hamstrings and one under the tibia.

Not to mention when I see people do this like the above -butt on foot, both hands on tibia- I see people yank the fuck out of the knee. If a ligament is gone, there is no need to pull for dear life. All that does is make the hamstrings more likely to contract, and potentially piss off the patient’s knee. A good orthopedist will find out your ACL is torn with you barely realizing they did anything.

Body positioning influences hamstring tone

The next way I’ve seen two physicians screw this up is they didn’t have me completely on my back. Think about laying flat on the floor. As you lean up more and more, you get more and more of a stretch in the back of your legs. This is how many people stretch their legs. The hamstrings get pulled on more and more. (If you want a detailed look at hamstring anatomy and this, see here.)

As this person goes from completely on their back, to more and more upright, to more and more leaned over, the hamstrings get pulled more and more:

Seated Toe Touch Hamstring Stretch

The more upright someone is, the more likely the hamstrings are already engaged. A person really needs to be fully supine to help relax the hamstrings. One surgeon I talked to said the person must be supine. Note this is to help relax the hamstrings. It’s not a guarantee. They still need to be touched.

Primary care physicians don’t know what they’re doing with this stuff. The physical therapists are a little better, but not much. My experience, ONLY orthopedists, and probably really only the sports oriented ones, know ACLs like you need to know them. This goes for the clinical exam, as well as assessing imaging. (Rehab is different.) I also had a radiologist tell me my ACL was fine. When I asked three orthopedists about that same MRI? All knew it was torn in seconds.

(If you have an insurance plan dictating you go to something like primary care first, that’s fine. But insist on seeing an orthopedist.)

To some degree, the others aren’t trained in this, so it’s understandable. To another degree, don’t do a damn test if you’re not doing it properly, or don’t do it often. Or, if you’re going to do it, you stipulate LOUDLY and repeatedly, “I don’t do this test regularly, so I suggest you still go to an orthopedist. I don’t have the feel they have.” Which is what I do whenever I test someone’s legs, which is practically never, because I already know I’m guessing. And I don’t want a client who has a lot of trust in me to think, “Eh, he seems to know what he’s doing. He’s probably right, nothing is torn. I won’t bother with an orthopedist.”

Otherwise you end up sending people off running with no ACL, as if they have one, like was done to me.

Subscribe to Blog via Email

Enter your email address to subscribe to this blog and receive notifications of new posts by email.