Radiographic Evaluation of HAV Flashcards Preview

Biomechanics & Surgery Exam 4 > Radiographic Evaluation of HAV > Flashcards

Flashcards in Radiographic Evaluation of HAV Deck (39)
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1
Q

should radiographs for evaluating HAV be done WB or NWB?

A

WB

2
Q

how is the hallux interphalangeus angle measured?

A

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

3
Q

what is the normal hallux interphalangeus angle?

A

less than 10 deg

4
Q

how is the hallux abductus angle measured?

A

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

5
Q

what is the normal hallux abductus angle?

A

less than 15 deg

6
Q

how is DASA measured?

A

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

7
Q

what is the normal DASA?

A

0-8 deg

8
Q

what does DASA tell you?

A

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

9
Q

how is PASA measured?

A

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

10
Q

what does PASA tell you?

A

evaluates position of articular cartilage of 1st met head

11
Q

what is normal PASA?

A

0-8 deg

12
Q

how is IM angle measured?

A

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

13
Q

what is normal IM angle?

A

0-10 deg

14
Q

what is considered a mild-moderate deformity?

A

10-15 deg

15
Q

what is considered a severe deformity?

A

> 15 deg

16
Q

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

A

perform procedures more proximally at the base of the met

17
Q

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

A

distal metatarsal osteotomy

18
Q

how is the metatarsus adductus angle measured?

A

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

19
Q

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

A

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

20
Q

list the reference values indicating severity of metatarsus adductus angle.

A

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

21
Q

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

A

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

22
Q

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

A

(# of met met adductus - 15) + IM

23
Q

how do you evaluate joint positions?

A

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

24
Q

how is a congruous joint described?

A

articulating lines are parallel

25
Q

how is a deviated joint described?

A

lines intersect outside the joint

26
Q

how is a subluxed joint described?

A

lines intersect inside the joint

27
Q

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

A

structural deformity
*joint is congruent
PASA/DASA abnormal

28
Q

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

A

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

29
Q

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

A

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

30
Q

which shape of metatarsal head is most unstable?

A

round head

31
Q

which shape of metatarsal head is most stable?

A

square w/ ridge

32
Q

how is metatarsal protrusion distance measured?

A

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

33
Q

what is normal metatarsal protrusion distance?

A

+/- 2mm

34
Q

what does metatarsal protrusion distance tell you?

A

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

35
Q

how do you measure tibial sesamoid position?

A

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

36
Q

what is the normal positions for tibial sesamoid?

A

positions 1,2,3

37
Q

what is the abnormal positions of tibial sesamoid?

A

positions 4-7

38
Q

what is tibial sesamoid position used for?

A

indication for removal of fibular sesamoid

39
Q

what can you look for on a lateral view radiograph?

A

1st ray elevation
hammer toes
hallux crossing over second