Pediatric Orthopaedic Exams: The Knee

Theodore Ganley, MD, Orthopaedic Surgeon and sports medicine specialist at Children's Hospital of Philadelphia (CHOP), demonstrates how to properly perform a knee exam on a pediatric patient, which includes assessment for varus and valgus deformities, Osgood-Schlatter disease, stress fractures, medial tibial periostitis (shin splints), infrapatellar tendonitis, injuries to the anterior cruciate ligament (ACL) and other ligaments, and more.

Transcript

Pediatric Orthopaedic Exams: The Knee

Theodore J. Ganley, MD: OK. So I'm Dr. Ganley, Ted Ganley, from The Children's Hospital of Philadelphia. I'm an Orthopedic Surgeon. I'll be demonstrating a knee exam. So, welcome. We'll be checking your knee today. OK. 

And so we'll start with the gait portion of the exam. So we watch him walk for us, and we make sure he has level shoulders, level pelvis, and a symmetric heel-toe gait. We look at his lower extremities and make sure he doesn't have a significant varus or valgus, meaning bow-legged or knock-kneed, and we look at his foot progression angle to see if his feet turn inward or outward during his gait. And make sure he doesn't have any antalgic component of his gait or painful or stiff-legged gait. 

So after we watch the patient walk, we observe them standing, and we make sure, again, they have a level shoulder and pelvis, make sure they have … we look for their alignment. Do they have varus or valgus, meaning bow-legged or knock-kneed. You can bring your feet together. And so he has appropriate alignment. And his patella, his kneecaps face forward as well.

OK. So we'll have you lie face-down then for you. And then scoot back toward me just a little bit. And then we'll check hip rotation, and so we'll bring the feet up to 90 degrees, then we'll internally rotate the hips. And he internally rotates on the order of 60 degrees, and we'll come to neutral, and he externally rotates 45 degrees. So he has little femoral inversion, which is more internal rotating than external rotation. 

And then we'll check his lower legs. And he has a neutral foot-thigh angle — the line longitudinal access of the femur relative to the foot — so that's a 0-degree foot-thigh angle, or he can have external rotation or internal rotation of the lower legs. And he has a 0-degree foot-thigh angle, and he also has a straight lateral border of each foot. 

So we'll be demonstrating areas of point tenderness, most commonly the anterior tibial tubercle, the infrapatellar tendon, the medial lateral peripatellar regions, and the quadriceps tendon. We will also be showing the medial collateral ligament — origin, midpoint and insertion; the lateral collateral ligament — insertion, midpoint and origin. We'll be showing the menisci, medial meniscus, lateral meniscus, as well as the anterior cruciate ligament, and the posterior cruciate ligament.

OK. So now we'll check for areas of point tenderness, and kids can hurt directly over the front of the knee, and I typically have them point or draw to their area of discomfort. And in his case he can have tenderness over the tibial tubercle, which is called Osgood-Schlatter's condition. They can have tenderness over the front of the tibia, which is most commonly stress reactions or stress fractures, the medial proximal tibia, medial tibial periostitis. 

It can hurt much less commonly over the tibia and fibula articulation, the tib/fib syndesmosis. They can hurt over the insertion of the hamstrings. The pes, the insertion of the semitendinosus, gracilis and sartorius, and they can get a bursitis at that location. They can have tenderness at the infrapatellar tendon, infrapatellar tendonitis. They can tenderness over their medial collateral ligament at its insertion, its midpoint, or the origin. Tenderness over the lateral collateral ligament, over the origin, insertion, midpoint or origin. Tenderness over the medial and lateral parapatellar regions. Anterior knee pain is common, tenderness all around the kneecap area. Or up high at the quadriceps, at the central portion, the vastus medialis or vastus lateralis, they can have quadriceps tendonitis. 

There's also areas of tenderness of the joint lines. The anteromedial joint line for anterior horn of the medial meniscus, the medial collateral ligament, posterior horn of the medial meniscus. They can have tenderness over their hamstrings, right along the back of the knee. On the lateral outer side of the knee, they can hurt right at the joint line over the anterior horn lateral meniscus, the lateral collateral ligament, or the posterior horn of the lateral meniscus, or over the hamstrings, hamstrings strains, or over the calf, or gastroc soleus for calf strains. 

So we'll start with the anterior cruciate ligament, and we flex the knee about 30 degrees, slightly externally rotate the hip to help the hamstrings relax, and we'll pull the lower leg forward to check for the anterior cruciate ligament. That's called a Lachman's test. Then we'll flex the knee up to 90 degrees. And then I tend to sit on the edge of the foot so it doesn't move, just slightly to the edge of the foot, then we'll pull the tibia forward to check for an anterior drawer test, for the anterior cruciate ligament. And then he has appropriate end point with that testing. And we'll check for posterior drawer test to check for the posterior cruciate ligament, which is a posterior-directed stress. And we'll push backward, and he has firm end point with that test as well. Then we'll bring the knee out straight, and we're checking for the collateral ligaments. The medial collateral ligament, we'll flex the knee a few degrees, and the hand to the lateral side of the knee, and the medial side of the lower leg, and we'll give a valgus stress. And again, he has a nice firm end point. 

For the lateral collateral ligament, we will bring the foot slightly over the edge of the table to drop the foot down to slightly flex the knee, a hand to the medial side of the knee, and the lateral side of the lower leg, and we'll give a varus stress to the knee. And this allows us to check for the lateral collateral ligament, and he has a nice firm end point and no pathologic laxity. We also check the opposite knee for all ligaments to make sure they have symmetric translation. 

So for the medial patella femoral ligament — which runs from the patella to the femur — we will do a lateral translation called an apprehension test. So we'll translate and see does the patella translate one, two, three, or four quadrants laterally; one, two, three, or four quadrants medially. And so we'll give a lateral directed stress to the patella, and he translates one and half quadrants laterally, and the same medially. And he has a negative apprehension test because he doesn't stop or say it feels as if it's translating out inappropriately.

Topics Covered: Anterior Cruciate Ligament (ACL) Injuries, Meniscus Tears (Knee Injuries), Anterior Knee Pain

Related Centers and Programs: Division of Orthopaedics, Sports Medicine and Performance Center