Chpt 13-18: lesser digital deformities Flashcards
lesser digital deformities/flail toe/FDL transfer/surgical repair of 5th digit
what is the most common mechanical etiology for HT
flexor stabilization
foot type and causes for flexor stabilization
pronated foot, equinus, peripheral neuropathy, tarsal tunnel
Mechanical causes for flexor stabilization
long flexors gain mechanical advantage over interosseous muscles, and quadratus plantae causing adductovarus to 4th and 5th digit
Foot type/cause for flexor substitution
weak tricep surae muscles, so flexors gain mechanical advantage over interossei
foot type/causes for extensor substitution
pes cavus, anterior cavus, CMT
Mechanical advantage of extensor substitution
EDL gain mechanical advantages over lumbricals causing retrograde buckling of digits
Hammer toe deformity
MPJ: DF
PIPJ: PF
DIPJ: neutral
Claw toe deformity
MPJ: DF
PIPJ and DIPJ: PF
Mallet toe deformity
MPJ: neutral
PIPJ: neutral
DIPJ: plantarflexed
advantages for peg in hole arthrodesis
avoids excessive shortening
Where should the extensor tenotomy be made
stab incision made PROXIMAL to extensor hood (ie at least 2 cm proximal to the MPJ)
Where should the flexor tenotomy be made for claw toe?
DIPJ—> only FDL released–> indicated for flexible claw toes
where should flexor tenotomy be made for hammer toe
PIPJ–> release long and short flexors DIPJ
why is it suggested to fuse toe in mild plantarfleion
to prevent mallet deformity from unstrained flexor pull
for an extensor lengthening, where shoudl the EDL and EDB be transected
EDL transected distal to the MPJ and EDB transected proximal to MPJ to complete Z plasty
” cut the longus long and the brevis short”
possibel surgical options for flail toe
implant arthroplasty
syndactylization
bone graft
amputation
Indication for syndactylization
flail digits, heloma molle
syndactylization is performed at well level of soft tissue
dermis
for lachmann test, subluxation greater than _______ indicates displacement/rupture
2mm
Anatomical relation of lumbricals, interossei and DTML
lumbricals is plantar to DTML and interoseei dorsal to DTML
incisional placement for adductovarus 5th digit? how will incision change the position of toe as it gets more vertical
incision with axis of orietnation from proximal lateral to distal medial centered over the PIPJ to allow for bone resection. The more vertical the incision, the more abduction
Indications for Weil osteotomy
Metatarsalgia
elongated metatarsal w/ or without transverse plane deformity
crossover toes
subluxed, dislocated MPJ
Rheumatoid
avoid weil osteotomy with what procedure? why?
PIPJ artrhodesis to avoid floating toe
Osteotomy cut placement for Weil osteotomy on 2nd met
1-2 mm inferior to most dorsal aspect of articular cartilage ad osteotomy is parallel to weight bearing surface
how should the osteotomy cut should be on the lesser mets compared to 2nd met
angle of osteotomy decreases on the lateral mets because they are less plantarflexed than 2nd met
how long would the weil osteotomy cut be?
2.5- 3 cm long
The average amount of metatarsal head shortening of weil osteotomy
3-5 mm normal amount of shortening ( 3 mm preferred)
what is the average screw length for weil osteotomy
2.0 or 2.4 x 12 mm screw fits most without penetrating plantar met head
post op protocol for weil osteotomy
PWB in surgical shoes for 4-6 weeks, then transfer to shoes
what does it indicate when the toe is dorsally subluxed after weil osteotomy
too much shortening, which will weaken flexors an intrinsic muscles
most common complication for weil ostoetomy
floating toe `
the greater the angle of osteotomy for weil, will have what effect
the greater the osteotomy angle, the greater the plantar displacement
for mpj arthroplasty what would you rather resect
met head over the base of roximal phalanx due to floppy toe
complications for MPJ arthroplasty
stiffness to MPJ, transfer metatarsalgia, floating toe
most common complication for condylectomy for high IM angle
joint subluxation
what do you want to avoid when doing a condylectomy
removing lateral and plantar condylectomy as it will weaken met head and lead to fragmentation
