Radiographic Angles Flashcards
Name the angular relationships found in the dorso-plantar projection.
- talocalcaneal angle (angle of Kite)
- cuboid abduction angle
- metatarsus adductus angle
- intermetatarsal angle
- tibial sesamoid position
- hallux abductus angle
- hallux interphalangeal angle
- proximal articular set angle (PASA)
- distal articular set angle (DASA)
- metatarsal protrusion distance
Name the angular relationships found on the lateral projection.
- calcaneal inclination angle
- talar declination angle
- cyma line
- Fowler-Phillip angle
- Bohler’s angle
- Talometatarsal angle (Meary’s angle)
- critical angle of Gissane
- 1st MPJ structure
what is the Talocalcaneal angle (angle of Kite)?
measure of the transverse plane angular relationship of the longitudinal bisectors fo the talus and calcaneus
what is the normal talocalcaneal angle (angle of kite)?
ages 0-5: (35-50 deg)
ages 5-adult: (15-35 deg)
how does talocalcaneal angle change in STJ pronation/ supination?
- increases in STJ pronation
- decreases in STJ supination
what is the talocalcaneal angle used to measure?
evaluate flatfoot deformity
what is the cuboid abduction angle?
a measure of the most lateral surface of the cuboid and calcaneus
what is the normal cuboid abduction angle?
0-5 deg
how does cuboid abduction angle change with pronation?
results in increased abduction
what is the metatarsus adductus angle?
bisection of lesser tarsus and bisection of 2nd met (or intermediate cuneiform)
*gives the relative position of the forefoot to the rearfoot
what is the normal metatarsus adductus angle?
0-15 deg
what is the metatarsus primus adductus angle?
represents a deviation of the 1st met relative to the 2nd
what is the normal metatarsus primus adductus angle?
8-12 deg
*w/ adductus, the normal decreases to 8-10 deg
what is the 1st intermetatarsal angle used to evaluate?
hallux abducto valgus deformity
-will determine the type of procedure you choose to do
what is the tibial sesamoid position?
change in sesamoid position that occurs relative to teh 1st met head
*there are 7 positions(gradually drifts laterally)
what are the normal tibial sesamoid position?
positions 1-3
what is the hallux abductus angle?
bisection of proximal phalanx and bisection of 1st met
*quantifies the lateral deviation of the hallux in HAV
what is the normal hallux abductus angle?
10-15 deg
what is the hallux interphalangeal angle?
bisection of distal phalanx and bisection of proximal phalanx
*represents the lateral hallux deviation at level of IPJ
what is the normal hallux Interphalangeal angle?
0-10 deg
what is PASA (proximal articular set angle)?
-bisection of 1st met, draw line that guesstimates effective articular surface at the head of 1st met, and a line perpendicular to the 1st met bisection
what is normal PASA?
7.5 deg
what is DASA (distal articular set angle)?
bisect proximal phalanx. draw line perpendicular to it. Drw a line guesstimating distar articular surface
what is normal DASA?
7.5 deg
what is metatarsal protrusion distance?
measurement difference in length btwn the 1st and 2nd mets
what is the normal metatarsal protrusion distance?
+/- 2mm
what is the calcaneal inclination angle?
angle representing inferior surface of calcaneus and weight supporting surface
what is normal calcaneal inclination angle?
18-21 deg
how does calcaneal inclination angle change with different foot types?
- decreased w/ pes planus
- increased w/ pes cavus
what is the normal talar declination angle?
21 deg
what is the cyma line formed by?
talonavicular joint + calcaneocuboid joint
anterior displacement of cyma line indicates what?
pronation
posterior displacement of cyma line indicates what?
supination
what is the fowler-phillip angle?
angle formed by the lines of the inferior surface of calcaneus and the posterosupero tuberosity of calcaneus
what is the normal fowler-phillip angle?
44-69 deg
what is the fowler-phillip angle used to evaluate for?
haglund’s deformity
what is bohler’s angle?
- one line is formed by postero-superior surface of calcaneus
- the other is formed by anterior process
what is the normal bohler’s angle?
25-40 deg
how does bohler’s angle change with a calcaneal fracture?
decreases
what is the talometatarsal angle (Meary’s angle)?
angle formed by teh bisection of the talus and 1st met
what is the normal talometatarsal angle?
0-10 deg
what is the critical angle of Gissane?
- draw a line thru posterior and middle facet of calcaneus
* draw another line thru the middle and anterior facet of calcaneus
what is the normal critical angle of Gissane?
120-145 deg
how does critical angle of Gissane chaange with fracture?
increases
what is a deviated joint?
when lines cross OUTSIDE the joint
what is a subluxed joint?
when lines cross INSIDE the joint
what is a dislocated joint?
no relationships between the lines