Radiographic Evaluation of HAV

Question 1

should radiographs for evaluating HAV be done WB or NWB?

Answer 1

WB

Question 2

how is the hallux interphalangeus angle measured?

Answer 2

angle formed by the longitudinal bisection of proximal phalanx and distal phalanx of the hallux

Question 3

what is the normal hallux interphalangeus angle?

Answer 3

less than 10 deg

Question 4

how is the hallux abductus angle measured?

Answer 4

angle formed by the bisection of the long axis of the proximal phalanx and 1st met

Question 5

what is the normal hallux abductus angle?

Answer 5

less than 15 deg

Question 6

how is DASA measured?

Answer 6

angle formed by the long bisection of the proximal phalanx and the line perpendicular to the line formed by marking cartilage of the base of proximal phalanx

Question 7

what is the normal DASA?

Answer 7

0-8 deg

Question 8

what does DASA tell you?

Answer 8

looks at angular deviation of the cartilage at base of proximal phalanx

Question 9

how is PASA measured?

Answer 9

angle formed by line perpendicular to long bisection of 1st met and a line formed by marking 1st met head cartilage

Question 10

what does PASA tell you?

Answer 10

evaluates position of articular cartilage of 1st met head

Question 11

what is normal PASA?

Answer 11

0-8 deg

Question 12

how is IM angle measured?

Answer 12

angle formed by the longitudinal bisection of 1st met and 2nd met

Question 13

what is normal IM angle?

Answer 13

0-10 deg

Question 14

what is considered a mild-moderate deformity?

Answer 14

10-15 deg

Question 15

what is considered a severe deformity?

Answer 15

> 15 deg

Question 16

what surgical approach would you use to correct a severe deformity (>15IMA)?

Answer 16

perform procedures more proximally at the base of the met

Question 17

what surgical approach would you use to correct a mild-moderate deformity (IMA is 10-15 deg)?

Answer 17

distal metatarsal osteotomy

Question 18

how is the metatarsus adductus angle measured?

Answer 18

angle formed by line perpendicular to midfoot bisection and long bisection of 2nd met

Question 19

name the 4 points used to create midfoot bisection for metatarsus adductus angle.

Answer 19

1st met-cuneiform joint
talonavicular joint
calcaneal-cuboid joint
4th met-cuboid joint (or 5th met)

Question 20

list the reference values indicating severity of metatarsus adductus angle.

Answer 20

0-15 deg: normal
16-25 deg: mild
26-35 deg: moderate
>35 deg: severe

Question 21

what is an alternate way to measure bisection of midfoot needed for metatarsus adductus angle?

Answer 21

angle formed by bisections of intermediate cuneiform and 2nd met
*this overestimates the angle by 5-10 deg though

Question 22

how do you calculate the true IM angle of a patient with metatarsus adductus angle > 15 deg?

Answer 22

(# of met met adductus - 15) + IM

Question 23

how do you evaluate joint positions?

Answer 23

draw a line on articular surface of 1st met head and on proximal phalanx

Question 24

how is a congruous joint described?

Answer 24

articulating lines are parallel

Question 25

how is a deviated joint described?

Answer 25

lines intersect outside the joint

Question 26

how is a subluxed joint described?

Answer 26

lines intersect inside the joint

Question 27

if PASA + DASA = HAA how would you classify this HAV deformity? describe the joint in this situation.

Answer 27

structural deformity *joint is congruent PASA/DASA abnormal

Question 28

if PASA + DASA is less than HAA, how would you classify this HAV deformity? describe the joint in this situation.

Answer 28

positional deformity *joint is deviated/ subluxed PASA/DASA normal

Question 29

if PASA + DASA is greater than HAA, how would you classify this HAV deformity? describe the joint in this situation.

Answer 29

combined deformity *joint is deviated /subluxed PASA/DASA abnormal

Question 30

which shape of metatarsal head is most unstable?

Answer 30

round head

Question 31

which shape of metatarsal head is most stable?

Answer 31

square w/ ridge

Question 32

how is metatarsal protrusion distance measured?

Answer 32

bisect 1st and 2nd met; draw their respective arches. the distance btwn the 2 should be about 2mm.

Question 33

what is normal metatarsal protrusion distance?

Answer 33

+/- 2mm

Question 34

what does metatarsal protrusion distance tell you?

Answer 34

if 1st met is short or long (+) indicates long 1st met (-) indicates short 1st met

Question 35

how do you measure tibial sesamoid position?

Answer 35

relationship of the tibial sesamoid to the bisection of the 1st metatarsal shaft

Question 36

what is the normal positions for tibial sesamoid?

Answer 36

positions 1,2,3

Question 37

what is the abnormal positions of tibial sesamoid?

Answer 37

positions 4-7

Question 38

what is tibial sesamoid position used for?

Answer 38

indication for removal of fibular sesamoid

Question 39

what can you look for on a lateral view radiograph?

Answer 39

1st ray elevation hammer toes hallux crossing over second