(English captions by Andrea Matsumoto from the University of Michigan)
To ensure a thorough assessment it is best to preform the musculoskeletal exam of the
knee in a systematic way.
The following is a suggested order of exam that incorporates many of the common techniques
used for evaluating knee injuries.
Begin the exam with the patient in the standing position.
Look for evidence of gross deformity, muscular atrophy, symmetry of the patellar alignment,
evidence of varus or valgus positioning of the knee, or presence of pes planus or pes
cavus of the foot.
From a posterior view observe for more than two toes laterally, also called the "too
many toes" sign.
This can indicate an over-pronated foot or an abducted forefoot.
Have the patient perform a toe raise and evaluate the heel position.
Normally the heel should change from a neutral to a varus position.
Next observe the gait looking for an antalgic gait or excessive pronation or supination.
Next evaluate active range of motion.
If pain or limitation exists repeat the range of motion passively.
In a seated position test for knee extension.
In this position also observe patellar tracking.
And, internal and external rotation of the hip which can help identify referred knee
pain caused by hip pathology.
Also in the seated position, palpate anatomic landmarks for tenderness.
Palpate the distal quadriceps, quadriceps tendon, the patella, patellar tendon, the
tibial tuberosity, and the fat pads beneath the patella.
On the medial side palpate the medial collateral ligament, the medial joint line, the pes anserine
bursa.
On the lateral side, the lateral collateral ligament, the lateral joint line, and the
fibular head.
Posteriorly palpate the popliteal fossa and the distal hamstrings.
With the patient supine the leg can be fully extended to assess better for joint diffusion.
Compress the suprapatellar pouch, pushing the contents distally, and assess for increased
fluid.
Patellar ballottement can also be performed by compressing the patella and releasing quickly.
Observe for rapid rebound, which also indicated increased fluid pressure.
If a click or tap is felt a large effusion is present, also called the ballottable patella.
The patellar grind test assesses for patella-femoral syndrome.
With the knee extended push the patella into the trochlear groove of the femur.
Pain is a positive test.
The patellar inhibition test assess for patella-femoral syndrome also.
With the knee extended, push the superior aspect of the patella inferiorly as the patient
tightens the quadriceps muscle.
Pain or crepitus is considered a positive test.
The patellar apprehension test evaluates for patellar subluxation of dislocation.
With the knee extended push medially and laterally on the patella in an attempt to sublux the
patella.
If it is painful or the patient becomes apprehensive about the movement it is a positive test.
There are several tests commonly performed to evaluate for ligamentous laxity of the
knee.
Medial collateral ligament stability can be tested at zero degrees and thirty degrees
of flexion by applying a valgus force on the knee.
Lateral collateral ligament stability can also be tested at zero degrees and thirty
degrees of flexion by applying a varus force to the knee.
Laxity indicates a partial or complete ligamentous tear.
The Lachman�s test evaluates for a tear of the anterior cruciate ligament.
With the knee flexed to thirty degrees, stabilize the femur and pull the proximal tibia anteriorly.
Excessive motion or soft endpoint is a positive test.
The anterior drawer test assesses of a tear of the anterior cruciate ligament also.
With the knee flexed to ninety degrees and the foot planted on the table, push the proximal
tibia anteriorly.
Excessive motion or soft endpoint is a positive test.
The posterior drawer test assesses for a tear of the posterior cruciate ligament.
With the knee flexed at ninety degrees and the foot planted on the table, push the proximal
tibia posteriorly.
Excessive motion or a soft endpoint is a positive test.
The PCL sag test evaluates for a tear of the posterior cruciate ligament.
With both knees flexed to ninety degrees and feet planted on the table, view the knees
from the side to compare the position of the tibia.
Increased posterior sag of one of the tibias is considered a positive test.
The McMurray�s test evaluates for a miniscule tear.
With the patient supine and knee fully flexed, palpate the medial joint line and apply an
axial force along the tibia while externally rotating and extending the knee.
This maneuver is repeated palpating the lateral joint line while internally rotating the foot.
Pain, catching, or palpable clunk indicates a miniscule tear.
The bounce test also evaluates for a miniscule tear.
Grasp the heel, extend, and bounce the leg, gently forcing hyperextension.
Pain is a positive test.
In the prone position, Apley�s compression test evaluates for a miniscule tear.
Flex the knee to ninety degrees, apply an axial force along the tibia, and rotate the
tibia.
Pain is a positive test.
Ober�s test assesses for iliotibial band syndrome.
With the patient in the lateral position, the knee is supported and flexed to ninety
degrees.
Then extend and abduct the hip and release the knee support.
Failure of the knee to adduct is a positive test.
In the seated position, Noble�s test can also be used to evaluate for iliotibial band
syndrome.
With the knee flexed to ninety degrees, apply pressure over the lateral femoral chondral
and passively extend the knee.
Lateral pain around thirty degrees of flexion is a positive test.
In concluding the knee exam, it's important to document a neurovascular exam.
Here we demonstrate dorsalis pedis artery pulse, posterior tibial artery pulse, and
capillary refill testing.
A more thorough exam may be indicated based on patient history.
Subtitles by the Amara.org community