60: Radiographic Planning HAV - Frush Flashcards
should radiographs be WB or NWB?
WB
systematic review of radiograph
- soft tissue
- bone and cartilage quality
- angles and alignment
osteoporotic bone and bone cysts w/i 1st met head
AP view
jt space narrowing and exostosis
AP view
what view is this?
sesamoid axial radiographic view
Hallux interphalangeus angle
- Angle formed by the longitudinal bisection of proximal phalanx and distal phalanx of the hallux
- normal less than 10 degrees
Hallux abductus angle
- Angle formed by bisection of the longitudinal axis of the proximal phalanx and 1st metatarsal
- normal range is less than 15 degrees
distal articular set angle DASA
- Angle formed by longitudinal bisection of the proximal phalanx of the hallux and the perpendicular of the line formed by marking the medial and lateral aspects of the cartilage of the base of the proximal phalanx
- Looks at angular deviation of the cartilage of base of the proximal phalanx
- Normal = 0-8 degrees
proximal articular set angle PASA
- Angle formed by a line perpendicular to longitudinal bisection of the 1st met and a line formed by marking points of medial and lateral aspects of 1st met head cartilage
- Evaluates position of articular cartilage of the 1st met head
- Normal = 0-8 degrees
intermetatarsus angle
- Angle formed by longitudinal bisection of the 1st metatarsal and the second metatarsal
- Normal = 0-10 degrees
- Mild-Moderate deformity = 10-15 degrees
- Severe deformity = > 15 degrees
metatarsus adductus angle
- Angle formed by line perpendicular to midfoot bisection and longitudinal bisection of the second
- Points used to create perpendicular of midfoot are
- Medial most aspect of
- 1st met cuneiform joint
- Talonavicular joint
- Lateral most aspect of
- Calcaneal cuboid joint
- 4th met cuboid joint
- Medial most aspect of
- 0-15 normal
- 16-25 mild
- 26-35 moderate
- > 35 severe
- *alternative method to measure = angle formed by longitudinal bisections of the intermediate cuneiform and the 2nd metatarsal. Normal is 5-10 degrees higher for this form of measurement.
why is metatarsus adductus important in bunions?
- In patients with increased met adductus, patient may have severe bunion deformity even with mildly increased IM angle
- If met adductus angle > 15 degrees
- True IM = (met adductus – 15) + IM
what are joint positions?
- Defined by the relationship of a line representing the effective articular surface of the first metatarsal head and a line representing the effective articular surface of the proximal phalanx:
- Congruous joint-lines are parallel
- Deviated joint-lines intersect outside the joint space
- Subluxed joint-lines intersect inside the joint space
types of deformity
structural (bone) vs. positional (soft tissue) vs. combined
***
most unstable metatarsal head shape
Round = most unstable
square/oblique = relatively stable
square with ridge = most stable
normal metatarsal protrusion distance
- A measurement for the relative length of patterns of first and second metatarsals:
- Normal is +/- 2mm
what is medial cuneiform obliquity?
orientation of 1st met - cuneiform joint
may or may not be relevant to bunion
tibial sesamoid position
- The is the relationship of the tibial sesamoid to the bisection of the shaft of the first metatarsal:
- Normal-positions 1,2,3
- Abnormal-positions 4,5,6,7
- Used an an indication for removal of fibular sesamoid.
what should you look for on a lateral view?
- 1st ray elevation
- hammer toes
- hallux crossing over second
