Radiographic biomechanical interpretation of foot Flashcards
Nl metatarsal protrusion distance
+/- 2mm
Cuboid abduction angle
a measure of the most lateral surface of cuboid and calcaneus, indicative of deformity in transverse plane
Talocalcaneal angle
angle of kite, measure of transverse plane anglular relationship of longitudinal bisectors of talus and calcaneus
Nl Bohler’s angle
25-40, decreases with a calcaneal fx
Talar declination angle
measurement composed of column tali axis and plane of support
1st MPJ structure and position
variants secondary to the structural anatomy of 1st MPJ, see pic for different positions
Cyma line
defined as a lazy S curve formed by the T-N and C-C joints (chopart’s joint)
Shapes of 1st met head
round: unstable, HAV flat: stable, hallux limitus Flat with ridge: very stable, hallux limitus
Nl PASA
7.5 degrees
Different Tibial sesamoid position
7 positions, nl is position 1-3
Nl Hallux IP angle
0-10
Nl metatarsus adductus angle
0-15
Bohler’s angle
defines contour of dorsal surface of calcaneus
Metatarsus primus adductus angle
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
nl and adductus angles of metatarsus primus adductus angle
nl: 8-12 degrees adductus: 8-10 degrees
Talometatarsal angle
Meary’s angle, angle formed by bisection of talus and first met
Proximal articular set angle (PASA)
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
Nl calcaneal inclination angle
18-21 degrees, decreased with pes plano valgus, increased with cavus foot type
Nl Talar declination angle
21 degrees
Nl hallux abductus angle
10-15 degrees
Distal articular set angle (DASA)
measures relationship of effective articulating cartilage of base of proximal phalanx
Nl talocalcaneal angles
0-5: 35-50 degrees, 5-adult: 15-35 degrees
nl DASA
7.5
nl talometatarsal angle
0-10 degrees
Critical angle of Gissane
created by subchondral bone of posterior facet and of middle and anterior processes of calcaneus (downward and upward slopes of calcaneus superior surface)
Metatarsal protrusion distance
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)
Nl Fowler-Phillip Angle
44-69, sx are common when greater than 75
Displacements of Cyma line
anterior: pronation, posterior: supination
nl critical angle of gissane
120-145, increases with calcaneal fx
Transverse plane vs sagittal plane
Seen on AP, seen on lateral
angle of cuboid abduction angle
nl 0-5 degrees, pronation results in increased abduction
Metatarsus adductus angle
gives relative position of forefoot to the rearfoot in transverse plane, composed of a bisection of lesser tarsus and bisection of second met
Calcaneal inclination angle
sagittal plane position of calcaneus referenced to plane of support
Hallux interphalangeal angle
represents lateral hallux deviation at IPJ, increases in this value produce a lateral curvature of hallux which become clinically significant
Tibial sesamoid position
change in sesamoid position occurs relative to first met head, TSP is measured relative to bisection of 1st met
Hallux abductus angle
representation of transverse plane position of hallux relative to long axis of first met, quantifies the lateral deviation of the hallux in HAV
Fowler Phillip Angle
evaluation of posterosuperior surface and ifnerior surface of the calcaneus, evaluates for Haglund deformity
How to get talocalcaneal angle
long axis of calcaneus and bisect the talus
What is the talocalcaneal angle used for?
evaluate flatfoot deformity, increased with STJ pronation: everted heel, decreased in STJ supination
