Call 281-633-8600 for an appointment. In this video, Dr. J. Michael Bennett demonstrates and describes typical knee examination tests that he uses in evaluating patient injuries. Dr. Bennett is a Board Certified Orthopedic Surgeon and a Fellowship Trained Sports Medicine Specialist with offices in Sugar Land, TX, and in Houston, near the Houston Galleria.
Here’s a transcript of Dr. Bennett’s video:
Hello, my name is Dr. J. Michael Bennett and this is the next video on demystifying the orthopedic knee exam. We’re just going to go over some nuts and bolts and basically just kind of go over what we do as orthopedic surgeons and what we’re looking for when we evaluate a patient for a knee injury. Many of you go to the doctor’s office and we run through all these tests and we go through them pretty quickly and you don’t really know what we’re looking for and I’ll try to kind of explain that today.
Today we’re going to go over a knee exam and first and foremost, it’s important to really review the history of the knee injury and the mechanism in injury because that can really tailor what kind of exam that we do.
After we get a good history from the patient, the first thing we do is we look at the patient’s knee and look at the patient how they’re walking. If they’re walking into your office on crutches or if they’re limping, then that obviously gives us an idea of how much pain they’re in or what kind of injury they had regarding their knee.
The next thing we do is we look at the knee. We have them pull their sleeve up or their pant leg up and look at the knee if it’s swollen, if it’s bruised. If let’s just say they can’t bend the knee or extend the knee, that indicates definitely a fracture or some sort of the deeper injury that may need some further testing. So first and foremost, we’ll look at the knee see if there’s any swelling or abnormality in the knee.
We’ll see if they can actually extend the knee and if they can lift the leg up on their own then that usually tells us a lot. That tells us that number one, their kneecap is working, their quad tendon’s intact, the patella tendon’s intact. Some patients that can’t lift their leg straight up –that just tells us that there’s a deficit between the quadriceps and the patella tendon here and the patella. That whole mechanism’s not working. So it could be a patella fracture, it could be quad tendon rupture, it could be patella tendon rupture.
So the next thing we do is we have them bend their knee and look at their motion. I always compare it to the other knee. Because if one knee bends all the way down here and the other knee doesn’t or bends further then there’s something wrong with this knee. I mean maybe it’s stiffness, maybe it’s arthritis, maybe something physically is getting caught in the knee keeping them from fully bending the knee especially if it’s painful. So you compare it to both knees looking at their range of motion in full flexion and full extension.
The next thing we’ll do is have them bend the knee and we’ll do what’s called an anterior-posterior drawer test. We have the knee at about 90 degrees here and we just pull and push the knee and see if there’s any kind of translation from the tibia to the femur and that gives us an idea of what the cruciate ligaments are doing, the anterior cruciate ligament or the posterior cruciate ligament.
The next thing I like to do is palpate the joint on the inside aspect, the joint line or the outside aspect of the joint line. If the patient comes in and they have specific pain on one side or the other side, that usually indicates a cartilage injury or maybe a contusion, specifically on the medial or lateral side of the joint but this kind of helps us make sure they don’t have any kind of meniscus pathology or cartilage lesions.
The next thing we do is have them bring the knee back to full extension and then I flex them to about 30 to 40 degrees, and then do a light translation of the knee to see if their ACL’s intact. It’s called a Lachman’s exam. So it’s either a Lachman’s positive or negative exam. There are different grades of Lachman’s. You can have an ACL sprain, which may give you a little bit more looseness or laxity on one side compared to the other but we use this test to see the integrity of the ACL ligament.
Next, I like to look and see if the patient has an effusion or any swelling in the joint. We’ll kind of squeeze the upper area of the joint and kind of palpate down and see if there’s any sponginess or swelling in the joint itself that will indicate some sort of inflammatory process in the knee.
Then I evaluate the kneecap and I’ll actually push on the knee cap see if the knee cap slides laterally on the outside or slides medially. If the patient does not like you doing this or they jump up or they want you to stop, that is a patellar apprehension test and that means that that kneecap’s unstable and it may mean that the ligament on the inside that actually helps stabilize that kneecap is stretched or torn and you don’t want to push that too far over. You don’t want to stress it too much because you could very well create a patellar dislocation. So you just very lightly, translate the kneecap forward and sideways.
If you have pain on the outside aspect of the kneecap, then it may mean you may have a little cartilage wear on the outside of the kneecap. There may be a tracking injury like patella-femoral syndrome in the kneecap where the kneecap’s just a little tilted because of the weakness in the quadriceps. So this tells us a lot.
Next, we’ll just bend the knee again. We’ll palpate the patella tendon or the quad tendon just to make sure there’s no patella tendonitis or quad tendonitis. We’ll evaluate the ligaments on the inside and the outside of the knee. So we’ll basically have the knee, drop it over the side of the table, flex it about 30 to 40 degrees and stress it outside and stress it inside. This tests the medial collateral ligament and the lateral collateral ligament. Then we bring it to full extension and stress it again inside and outside. That will tell us if the collateral ligaments are intact or if there’s any sprain or injury to the collateral ligaments.
The next thing we do is something called the McMurray’s or Steinman’s test. We’ll actually hyperflex the leg and we grab the foot and we rotate that ankle and that knee and we’ll bring the leg to full extension. Then we rotate and swivel it at the other way and bring it into full extension. That tells us that if you have any kind of meniscus pathology. If you have pain when you rotate the knee or the patient comes in and says, “Oh yeah, when I twist and turn, I have significant pain the knee joint, ” that will indicate a meniscus tear so an MRI is often warranted in that case.
Just like I mentioned before if we’re looking for swelling in front of the knee you can have swelling in the back of the knee. Some patients will come in and say they have a lot of fullness in the back of the knee or swelling in the back of the knee. Many times that could be a mass in the back of the knee. It could be a Baker’s cyst, which is a benign fluid-filled cyst in the back of the knee that usually occurs when we have any kind of swelling in the joint or effusion in the joint. The cyst occurs because the fluid goes to the pathway of least resistance and sometimes posteriorly in the back of the knee.
It’s a good idea if you’re having any significant knee injuries or knee issues to get an evaluation by an orthopedic sports medicine physician and knee specialist. So hopefully that helps demystify a little bit of typical orthopedic knee exam tests. If you have any questions or comments, please go to our website at www.orthopedicsportsdoctor.com or call us at 281-633-8600. Thank you.
Dr. Bennett has been selected as a Texas Super Doctor® for the last three years. He’s Board Certified in Orthopedic Surgery and he’s a Fellowship Trained Sports Medicine Specialist. Call us at 281-633-8600 for an appointment.