Tailor's Bunion Flashcards
What is “Tailor’s bunion deformity”?
abnormally prominent 5th metatarsal head, usually in a varus angulation
what is the 5th ray axis?
20 deg from transverse and 35 deg from sagittal plane
what is the greatest motion that occurs about the 5th ray axis?
frontal plane motion- inversion/eversion
the 5th ray axis runs parallel to which axis?
MTJ oblique axis
how many deg of tri-plane motion are there in the 5th ray?
10 deg
List the structural causes of Tailor’s bunion.
- increased IM angle
- bowing of the metatarsal
- dumbbell shaped met head
- accessory ossicle
- soft tissue hypertrophy
list the functional causes of Tailor’s bunion.
- uncompensated RF varus
- uncompensated FF varus
- FF valgus foot types
what will a tailor’s bunion look like on radiograph?
- plantar concavity of the shaft becomes laterally positioned, making the shaft appear to be curved
- plantar condyles become laterally positioned and are mistaken for exostosis
What is the normal IM angle between the 4th and 5th toes?
6.22-6.47 deg
What is the clinical designation for a tailor’s bunion based on IM angle of Fallat and Buckholz?
> 8.71 deg (or just >8 deg)
What is the normal lateral deviation angle?
2.65- 7.5 deg
what is clinically designated as a tailor’s bunion based on lateral deviation angle of Fallat and Buckholz?
> 8 deg
what is considered a splayfoot deformity?
IM angle >12 deg btwn the 1st and 2nd mets
and an IM angle >8 btwn 4th and 5th mets
tailor’s bunion is commonly seen with adductovarus deformity. why?
as the 5th met shaft everts, the abductor digiti quini is placed more plantarly so it loses its abductory force on the 5th toe, making the toe adduct and moving into a varus position.
what is considered the normal 5th met declination angle?
10 deg
