Knee Joint Exam

Question 1

What are some observable/palpable landmarks of the knee?

Answer 1

• medial and lateral tibial plateau
• medial and lateral femoral condyles
• adductor tubercle
• anserine bursa
• medial/lateral joint lines
• head of fibula
• common fibular n
• quadriceps
• infra(patellar) tendon
• patella
• prepatellar bursa
• medial and lateral meniscus
• medial and lateral collateral ligament
• sartorius, gracilis, semitendinosus tendons
• popliteal fossa
• popliteal artery
• posterior tibial n (popliteal fossa)
• superficial peroneal n (fibular head)
• recognize genu valgum/varus/recurvatum

Question 2

what is the Q-angle?

Answer 2

• normal is 15 deg
• measure by creating a straight line from the ASIS to the center of patella and another line through the tibial tuberosity and the same point on the patella
• this difference between these two lines forms the Q-angle
• females typically have increased Q angle

Question 3

ROM of knee: flexion

Answer 3

• 145-150
• hamstrings: biceps femoris (long and short heads), semitendinosus, semimembranosus
• tibial n L4-5 and S1-3 (branch of sciatic n)

Question 4

ROM of knee: extension

Answer 4

• 0 degrees
• quadriceps: rectus femoris, vastus lateralis, vastus intermedius, vastus medialis
• femoral n (L2-4)

Question 5

What are the dermatomes around the knee?

Answer 5

• dermatomes - L3-5, S2

- patellar reflex - L4 primarily (L2-4)

Question 6

Valgus stress test

Answer 6

• patient supine and exmainer supports patient’s lower leg on the examiner’s hip, with the knee flexed to 30 deg (also test at neutral)
• examiner’s hands are placed on the medial and lateral aspects of the patient’s knee
• while providing lateral resistance at the knee, move the lower leg so that the ankle shifts laterally while holding femur in place
• asses for laxity, quality of end point and pain
• if (+): increased laxity, soft or absent endpoint, or pain
• indicates MCL disruption (if also + at 0 deg/knee fully extended indicates joint capsule injury)

Question 7

ROM of knee: external/internal rotation

Answer 7

• 10 degrees

Question 8

Varus stress test

Answer 8

• examiner and patient in same as position as in valgus stress test
• while providing medial resistance, examiner moves the lower leg so that the ankle shifts medially
• this test is done at 30 deg flexion and neutral (0 deg)
• if (+): increased laxity, soft or absent endpoint, or pain
• indicates LCL disruption - more severe injury indicated if also positive at 0 deg

Question 9

Lachman’s test

Answer 9

• patient supine
• examiner places cephalad hand on distal thigh, superior to patella
• caudad hand grasps proximal tibia
• flexing knee to 15-30 deg, examiner uses his caudad hand to pull the tibia anteriorly while the cephalad hand stabilizes the thigh
• if (+): increased laxity, soft or absent end point
• indicates ACL insufficiency

Question 10

Anterior drawer test

Answer 10

• patient supine with knee flexed to 90 deg
• examiner sits on patient’s foot and grasps the proximal tibia with both hands, pulling tibia anteriorly
• if (+): excessive translation when compared to the other knee
• indicates ACL insufficiency

Question 11

Posterior drawer test

Answer 11

• patient supine with knee flexed to 90 deg
• examiner sits on patient’s foot and grasps proximal tibia with both hands, translating tibia posteriorly
• if (+): excessive translation, particularly when compared to the opp side
• indicates PCL deficiency, posterior capsular injury or disruption

Question 12

Reverse Lachman’s test

Answer 12

• patient supine
• examiner places cephalad hand on the distal thigh, superior to patella
• caudad hand grasps proximal tibia
• flexing knee to 15-30 deg
• proximal hand stabilizes femur while distal hand pushes tibia posteriorly
• if (+): increased laxity, soft or absent end point when compared to opp joint
• indicates PCL deficiencies/post capsule deficiency

Question 13

Patellar laxity test

Answer 13

• one hand above and one hand below the joint
• thumbs placed against side of patella
• examiner pushes patella medially and laterally, assessing ROM
• grading: 1-4 (+1 = 0/25%, +2 = 25-50% etcs)

Question 14

Patellar apprehension test

Answer 14

• when testing laxity to point of restriction, ask patient if maneuver provokes any discomfort or sense of instability
• if (+): sense of apprehension or instability
• indicates possible previous patellar dislocation or severe instability

Question 15

Patellar Compression (grind) test - normal

Answer 15

• patient supine and knee extended
• provide compressive load to patella with one hand moving patella medial and lateral
• if (+): pain with compression
• indicates possible inflammation, chondromalacia, or injury to the patellofemoral articular surfaces

Question 16

Patella-Femoral grinding variation

Answer 16

• compress patella caudally into trochlear groove and instruct patient to tighten quads against resistance
• if (+): crepitation or pain indicating roughness of articulating surfaces (ie chondromalacia)

Question 17

Patellar glide test

Answer 17

• patient sitting or supine will slowly extend and flex at knee, while physician notes quality of articular motion
• placing hand lightly over the patella can increase sensitivity of test
• if (+): palpable or audible crepitus, pain or catching of patella
• indicates possible damage to articular surface

Question 18

McMurray’s Test

Answer 18

• patient supine with hip and knee flexed
• examiner uses caudad hand to control the ankle and cephalad hand placed on distal femur
• testing medial meniscus: internally rotate tibia as knee is extended while adding varus load
• testing lateral meniscus: externally rotate tibia as knee is extended while adding valgus load
• if (+): pain or painful click during extension
• indicates possible meniscus tear

Question 19

Apley compression (grind) test

Answer 19

• patient prone with knee flexed to 90 deg
• examiner uses downward force on foot to provide a compressive force on meniscus while rotating the foot internally and externally
• if (+): pain with rotation and/or compression
• indicates meniscal injury, collateral ligament injury, or both

Question 20

Apley distraction test

Answer 20

• patient prone with knee flexed to 90
• examiner uses upward pulling force on the foot to provide a distraction on the meniscus while rotating foot internally and externally
• if (+): pain with distraction and rotation
• indicates collateral ligament damage