Foot and Ankle Flashcards
ankle coupled motion
fibula externally rotates and migrates proximally with ankle dorsiflexion
transverse tarsal joints during heel-strike, and position of the foot
parallel, supple. The foot is in dorsiflexion, forefoot abduction, and hindfoot valgus
transverse tarsal joints during toe-off
divergent, locked. Foot is in plantarflexion, forefoot adduction, hindfoot varus.
why there is no heel-rise in PTT deficiency
the PT is not able to lock the transverse tarsal joints
the primary stabilizer of the longitudinal arch of the foot
plantar interosseous ligaments, not the plantar fascia
hindfoot during foot-flat cycle
unlocked/everted for ground accommodation
hindfoot during heel strike cycle
unlocked/everted for energy absorption
windlass mechanism
as the MTPs extend during toe-off the plantar fascia is tightened, accentuating the longitudinal arch
foot exam: position of hindfoot in cavovarus
plantar flexed first ray, hindfoot varus
stance phase in antalgic gait
this is shortened. don’t want to linger on a painful limb
vascular predictors of adequate healing in the foot
toe pressures > 40mmHg, or TcPO2 > 30 mmHg
insensitivity to this size semmes-weinstein predictor of foot ulcer
5.07
varus stress test of the ankle evaluates this
calcaneofibular ligament
anterior drawer test of the ankle evaluates this
anterior talofibular ligament
how to perform test of calcaneofibular ligament
inversion of the ankle in dorsiflexion
why flexing the knee is part of the silverskiold test
the soleus doesn’t cross the knee joint, so if flexing the knee loosens an equinus contracture, it is just gastroc and not soleus
migration of this implicated in hallux valgus
plantar-lateral migration of the abductor hallucis, which causes the muscle to pronate and plantar-flex the phalanx
normal hallux valgus angle
less than 15 degrees
normal IMA (foot)
less than 9 degrees
normal DMAA
less than 10 degrees
this is never done by itself in hallux valgus
modified mcbride
Indications for chevron osteotomy, +distal soft tissue release
IMA 13* or less, -AND- HVA is 40* or less
indications for proximal metatarsal osteotomy, +distal soft tissue release
IMA >13, -OR- HVA >40
indications for adding distal medial closing wedge osteotomy to hallux valgus procedures
DMAA greater than 10*. Done IN ADDITION to other indicated procedures based on the angular measurements
this is highly associated with lapidus and proximal crescentic osteotomy
transfer metatarsalgia from dorsal malunion
common cause for iatrogenic hallux varus
overresection of the medial eminence during hallux valgus surgery
technical difference in the surgery to correct severe hallux valgus in adolescent
proximal osteotomy done through medial cuneiform instead of the first met if physes are open
complex hammer-toe
hammer-toe is hyperflexion of the PIP joint. with weightbearing the MTP joint appears dorsiflexed. if this does not go away when not weightbearing, it is considered complex
mgmt of flexible claw toe
flexor to extensor transfer; causes the FDL to act as an intrinsic
mgmt of fixed claw toe
depends on whether the MTP is reduced. If so, PIP arthroplasty/arthrodesis, MTP joint capsulotomy, and extensor lengthening. If the MTPJ is not reduced you will add a Weil distal MT osteotomy
key for mallet toe development
plantar plate attenuation (often iatrogenic - steroids)
indication for proximal osteotomy in bunionette deformity
because of blood supply concerns you don’t cut proximally on the fifth MT
indication for diaphyseal osteotomy in bunionette deformity
type 3, or 4-5 IMA >8*
indication for distal osteotomy in bunionette deformity
type 2, or those with distal lateral bowing
indication for distal condylectomy in bunionette deformity
type 1, or those with prominent MT head
the sesamoids are part of this tendon
flexor hallucis brevis
the sesamoids protect this tendon
flexor hallucis longus
turf toe type 1
1 - capsular strain, normal films, normal ROM. Immediate RTP
turf toe type 2
2 - painful ROM, limited weightbearing, normal films. Out for 2 weeks
turf toe type 3
3 - complete plantar plate rupture. abnormal films (proximal migration) requires plantar plate repair if migrated more than 3mm. Out 6weeks.
this occurs if bilateral sesamoidectomies are performed
cock-up toe deformity
this approach places the lateral plantar nerve at risk
incisions on the plantar surface (TTC nail)
etiology of the most common deformity of the foot in upper motor neuron disorders
equinovarus; equinus bc gastroc overactivity, varus bc everything medial to the ankle axis is overpulling. Mostly AT, but also FHL, FDL, and Tib Post
mgmt of flexible equinovarus due to upper motor neuron disorder
the equinus is fixed with TAL or Z lengthening. Since the varus is bc the medial sided muscles (usually AT) are overpulling, you can transfer all or part of AT to the lateral cuneiform
root cause of the plantar-flexion in CMT
overpull of the peroneus longus
result of the plantar-flexion in CMT
forefoot cavus, and resultant compensatory hindfoot varus
root cause of the compensatory hindfoot varus in CMT;
with the AT overpowered by the peroneus longus, the posterior tib can pull the hindfoot into even more varus, since the peroneus brevis can’t resist it
surgical mgmt of cavovarus
Everyone: release plantar fascia, dorsiflexion 1st MT (cotton) osteotomy, peroneus longus to brevis transfer, then test coleman block. If doesn’t correct, then add lateral calc slide or closing-wedge osteotomy
chronic gout treatment
been going on A-LONG time? ALLOpurinol
portion of foot involved in RA
forefoot more than mid or hind
deformity on the forefoot of RA
dorsal subluxation, valgus deviation, and hammering of the toes
why ankle fusion not always the mgmt of tibiotalar joint arthritis
it is, unless there is hindfoot arthritis (needs a triple) or already has a triple. Avoid ANYthing that would lead to a PANtalar fusion, which has horrible outcomes.
main concern with TAA in RA
would healing issues
most common complication of RA forefoot arthroplasty
intractable plantar keratoses
orthotic mgmt of hallux rigidus
stiff foot plate with morton first ray extension
orthotic mgmt of midfoot arthritis
stiffsoled or steel shank with rocker bottom
position for 1st met fusion in hallux rigidus
no rotation, a little bit of valgus, and enough plantarflexion to touch floor
to fix a malunited triple arthrodesis
transverse tarsal osteotomy to rotate into plantigrade, and calcaneal osteotomy to correct the varus or valgus
these increase the rate of nonunion of subtalar arthrodesis
prior tibiotalar arthrodesis and smoking. smokers actually heal better than prior fusions
this procedure leads to lower failure rate with the Agility TAA
syndesmotic fusion
who does best with TAA: RA, osteoarthritis, or post-traumatic
TAA shows the best outcomes in osteoarthritis
indications and potential drawbacks of subtalar bone-block arthrodesis
Done for pts with prior calcaneus fx with loss of height, but can have anterior ankle impingement and pain
rigid pes planus
triple
incompetence of this is associated with increasing flatfoot deformity
spring, or calcaneonavicular, ligament, which is the primary static stabilizer of the talonavicular joint
pes planus indicated radiographically by
negative mearys angle, or the lateral talometatarsal angle
orthotics for pes planus
medial post, medial wedge. AFO.
nonop mgmt for pes planus
AFO with physical therapy has shown the highest success rate
all stage II PTT includes this
FHL or FDL transfer to the navicular to reconstruct the PT.
stage II PTT that has hindfoot valgus and
add a MEDIAL calcaneal osteotomy. This adds power to the flexor tendon transfer, and corrects the hindfoot valgus
stage II PTT that has hindfoot valgus and >40% talar head uncovering includes this
same as stage 2 without forefoot abduction (TN uncovering), only you add lateral column lengthening (Evans): FDL/FHL transfer, medial calc slide, lat column lengthening
stage II PTT that has forefoot supination
depends on whether the medial column is stable or not; cotton if it is, fusion if it isn’t
stage III PTT
rigid = triple
peroneal tendon subluxation requires repair of
superior peroneal retinaculum
associated with plantar fasciitis
achilles tendon contracture
release of the plantar fascia can cause
obviously will stress the longitudinal arch, but can also overload the lateral column and lead to dorsolateral foot pain
muscle and nerve involved with Baxter’s neuritis
baxter’s nerve, obviously, which is the first branch of the lateral plantar nerve. Pain is located more medial than plantar fasciitis, over abductor hallucis
motor neuropathy of this is most common in diabetics
common peroneal nerve, which leads to footfrop (loss of AT) and the intrinsics which causes clawtoes and toe ulcers
minimum ABI for healing in diabetics
0.45mmHg
in diabetics these are lab values indicative of poor healing potential
total protein
swelling and redness of charcot compared to osteo
charcot is better in the morning, after it hasn’t been dependent all day
when can custom braces be done for charcot
after the warmth and swelling subsides
what technical step must be done in both lisfranc and chopart amputations
both need tendon transfers, but also need achille’s lengthenings, which prevent equinus
tendon transfer done after lisfranc amputation
to prevent varus you have to transfer the peroneal tendons to the cuboid
tendon transfer done after chopart amputation
to prevent varus you have to transfer the anterior tibialis tendons to the talus
foot amputation with lowest energy expenditure
transmet
foot amputation with second lowest energy expenditure
Syme
indications for fxs of 2-4 MT
more than 10* sagittal plane deformity or if all 3 are fxd.
purely ligamentous Lisfranc fx disloc’n
primary fusion
typical location of navicular stress fxs
central 1/3rd
gold standard for navicular stress fx diagnosis
CT scan
screw placement for navicular fxs
only done for displaced or evidence of nonunion, and placed from dorsolateral to plantarmedial
three blood supplies to the talus
body supplied by artery to the tarsal canal (deltoid br of posterior tibial), the neck supplied by dorsalis pedis and peroneal perforators
talus fxs with comminution in this location have this characteristic deformity
medial neck comminution leads to varus deformity
Varus malunion of a talus fx leads to
cavovarus deformity, which limits hindfoot eversion, and causes lateral foot pain
talar neck fxs: Hawkins good, Hawkins bad?
The subchondral lucency of the talus, or Hawkin’s sign, indicative of revascularization. GOOD…
laterality of the wound in open calcaneal fxs, with respect to complication rate
medial wounds do not increase the complication rate as much as lateral wounds
at risk during placement of lateral to medial screws while ORIF of calc fx
FHL, where it courses past the sustentaculum
obstacles to reduction in medial subtalar disloc’n
EDB, peroneal tendons, capsule
obstacles to reduction in lateral subtalar disloc’n
posterior tib, FHL
mechanism and location of lateral OCD talar lesions
dorsiflexion, inversion. Anterior.
mechanism and location of medial talar OCD lesions
plantarflexion, inversion, located posteriorly. Deeper, and occur spontaneously
full thickness P brevis tear
transfer peroneus longus
these peroneus brevis tears can be repaired
partial longitudinal tears
this treatment for OCD lesions results in hyaline cartilage formation
autologous osteochondral transplant
most common complication after Morton’s neuroma injection
hammertoe
mgmt of hallux varus that is passively correctable
split EHL transfer, MT osteotomy, medial capsule release. If it is not flexible, fuse it…
FHL transfers are done for this type of Achille’s tendon injury
chronic tears more than 5cm
only proven risk factor for mortons neuroma
female gender
