Radiographic biomechanical interpretation of foot

Question 1

Nl metatarsal protrusion distance

Answer 1

+/- 2mm

Question 2

Cuboid abduction angle

Answer 2

a measure of the most lateral surface of cuboid and calcaneus, indicative of deformity in transverse plane

Question 3

Talocalcaneal angle

Answer 3

angle of kite, measure of transverse plane anglular relationship of longitudinal bisectors of talus and calcaneus

Question 4

Nl Bohler’s angle

Answer 4

25-40, decreases with a calcaneal fx

Question 5

Talar declination angle

Answer 5

measurement composed of column tali axis and plane of support

Question 6

1st MPJ structure and position

Answer 6

variants secondary to the structural anatomy of 1st MPJ, see pic for different positions

Question 7

Cyma line

Answer 7

defined as a lazy S curve formed by the T-N and C-C joints (chopart’s joint)

Question 8

Shapes of 1st met head

Answer 8

round: unstable, HAV flat: stable, hallux limitus Flat with ridge: very stable, hallux limitus

Question 9

Nl PASA

Answer 9

7.5 degrees

Question 10

Different Tibial sesamoid position

Answer 10

7 positions, nl is position 1-3

Question 11

Nl Hallux IP angle

Answer 11

0-10

Question 12

Nl metatarsus adductus angle

Answer 12

0-15

Question 13

Bohler’s angle

Answer 13

defines contour of dorsal surface of calcaneus

Question 14

Metatarsus primus adductus angle

Answer 14

also called 1st intermetatarsal angle, representation of deviation of first met relative to second met, bisect the first and bisect the second met, evaluation of hallux abducto valgus-will determine what type of procedure

Question 15

nl and adductus angles of metatarsus primus adductus angle

Answer 15

nl: 8-12 degrees adductus: 8-10 degrees

Question 16

Talometatarsal angle

Answer 16

Meary’s angle, angle formed by bisection of talus and first met

Question 17

Proximal articular set angle (PASA)

Answer 17

representation of effective cartilage in relation to shaft of met, any increase in PASA is pathological and may either add to a structural or combined deformity

Question 18

Nl calcaneal inclination angle

Answer 18

18-21 degrees, decreased with pes plano valgus, increased with cavus foot type

Question 19

Nl Talar declination angle

Answer 19

21 degrees

Question 20

Nl hallux abductus angle

Answer 20

10-15 degrees

Question 21

Distal articular set angle (DASA)

Answer 21

measures relationship of effective articulating cartilage of base of proximal phalanx

Question 22

Nl talocalcaneal angles

Answer 22

0-5: 35-50 degrees, 5-adult: 15-35 degrees

Question 23

nl DASA

Answer 23

7.5

Question 24

nl talometatarsal angle

Answer 24

0-10 degrees

Question 25

Critical angle of Gissane

Answer 25

created by subchondral bone of posterior facet and of middle and anterior processes of calcaneus (downward and upward slopes of calcaneus superior surface)

Question 26

Metatarsal protrusion distance

Answer 26

measurement in difference in length between 1st and 2nd mets, impacts on procedure one does for bunion correction if the 1st met is short (most common)

Question 27

Nl Fowler-Phillip Angle

Answer 27

44-69, sx are common when greater than 75

Question 28

Displacements of Cyma line

Answer 28

anterior: pronation, posterior: supination

Question 29

nl critical angle of gissane

Answer 29

120-145, increases with calcaneal fx

Question 30

Transverse plane vs sagittal plane

Answer 30

Seen on AP, seen on lateral

Question 31

angle of cuboid abduction angle

Answer 31

nl 0-5 degrees, pronation results in increased abduction

Question 32

Metatarsus adductus angle

Answer 32

gives relative position of forefoot to the rearfoot in transverse plane, composed of a bisection of lesser tarsus and bisection of second met

Question 33

Calcaneal inclination angle

Answer 33

sagittal plane position of calcaneus referenced to plane of support

Question 34

Hallux interphalangeal angle

Answer 34

represents lateral hallux deviation at IPJ, increases in this value produce a lateral curvature of hallux which become clinically significant

Question 35

Tibial sesamoid position

Answer 35

change in sesamoid position occurs relative to first met head, TSP is measured relative to bisection of 1st met

Question 36

Hallux abductus angle

Answer 36

representation of transverse plane position of hallux relative to long axis of first met, quantifies the lateral deviation of the hallux in HAV

Question 37

Fowler Phillip Angle

Answer 37

evaluation of posterosuperior surface and ifnerior surface of the calcaneus, evaluates for Haglund deformity

Question 38

How to get talocalcaneal angle

Answer 38

long axis of calcaneus and bisect the talus

Question 39

What is the talocalcaneal angle used for?

Answer 39

evaluate flatfoot deformity, increased with STJ pronation: everted heel, decreased in STJ supination