B6.073 Joint Injuries

Question 1

3 compartments of the knee

Answer 1

medial
lateral
patello-femoral

Question 2

knee motion

Answer 2

modified synovial hinge joint

complex interaction of flexion, extension, rotation

Question 3

ACL

Answer 3

anterior translation of tibia and rotational stability

Question 4

PCL

Answer 4

restrain posterior translation of tibia and assist valgus/varus stability

Question 5

MCL

Answer 5

restrains valgus stressing

Question 6

LCL

Answer 6

restrains varus stressing

Question 7

what is the function of knee meniscii

Answer 7

made of fibroelastic cartilage (90% type 1)
optimizes force transmission
-by increasing contact area
-shock absorption
-also acts as secondary stabilizers

Question 8

posterior lateral corner of the knee

Answer 8

popliteus tendon
LCL
popliteo-femoral ligament

Question 9

function of posterior lateral corner

Answer 9

control external rotation

varus and posterior translation

Question 10

exams for the ACL

Answer 10

anterior drawer (flexed at 90)
Lachman (flexed at 20-30)

Question 11

exams for the PCL

Answer 11

posterior drawer

Question 12

exams for MCL

Answer 12

valgus stress test
-at 0 and 30 degrees
laxity at 30 = MCL injury
laxity at 0 = MCL and ACL/PCL

Question 13

exams for LCL

Answer 13

varus stress test
-at 0 and 30 degrees
laxity at 30 = LCL injury
laxity at 0 = LCL and ACL/PCL

Question 14

exams for PLC

Answer 14

dial test
positive is > 10 deg asymmetry
-at 30 = PLC injury
-at 30 and 90 = PLC and PCL injury

Question 15

unhappy triad

Answer 15

MCL, ACL, and medial meniscus
lateral meniscus tear probably more common
kissing contusion of lateral femoral condyle and posterior lateral tibial plateau

Question 16

what causes an unhappy triad

Answer 16

valgus force with tibial anterior translation and external rotation

Question 17

knee xray views

Answer 17

bilateral
standing PA
lateral
sunrise (merchant’s)

Question 18

management of unhappy triad

Answer 18

MRI right knee

ACL reconstruction +/- meniscal repair and MCL repair

Question 19

what joint facilitates ankle flexion/extension

Answer 19

talocrural joint (at meeting of talus and leg bones)

Question 20

what joint facilitates ankle inversion and eversion

Answer 20

subtalar joint (talocalcaneal)
transverse tarsal joint
-talonavicular
-talocuboid

Question 21

lateral ankle ligaments

Answer 21

anterior talofibular (ATFL)
calcaneofibular (CFL)
posterior talofibular (PTFL)

Question 22

anterior talofibular (ATFL)

Answer 22

restrains inversion while in plantar flexion

weakest ligament of lateral ankle

Question 23

calcaneofibular (CFL)

Answer 23

restrains inversion when neutral or in dorsiflexion

prevents subtalar inversion

Question 24

posterior talofibular (PTFL)

Answer 24

supplementary role in stability

prevents posterior talar displacement

Question 25

exams for the ankle

Answer 25

anterior drawer (20 deg plantarflexion for ATFL)
talar tilt (inversion stress test for CFL)

Question 26

medial ankle ligaments

Answer 26

deltoid ligament

• restrains valgus of talus
• resists eversion of hindfoot

Question 27

what is the ankle syndesmosis

Answer 27

maintains integrity of the mortise
comprised of:
anterior-inferior tibiofibular 
posterior-inferior tibiofibular
transverse tibiofibular
interosseous membrane

Question 28

tests for the syndesmosis

Answer 28

eversion stress test
-assesses deltoid
squeeze test
external rotation stress test
-assesses AITFL

Question 29

Ottawa ankle rules

Answer 29

1. cannot bear weight
PLUS one of:
-navicular
-5th metatarsal
-lateral malleolus
-medial malleolus

Question 30

Maisonneuve fracture

Answer 30

fails proximal squeeze test

fracture of proximal fibula