foot and ankle Flashcards
where does the spring ligament run?
calcaneus to navicular, supports talar head
primary stabilizer of longitudinal arch
interosseous ligaments
what is an Akin for?
increased HVI
IMA < 13 and HVA < 40
distal metatarsal osteotomy (chevron)
IMA > 13 or HVA > 40
proximal metatarsal osteotomy
risk factors for hallux valgus recurrence
undercorrection of IMA, isolated soft tissue reconstruction, isolated resection of the medial eminence
what does dorsal malunion after bunion surgery cause?
transfer metatarsalgia
risk factors for hallux varus after bunion surgery
resection of fibular sesamoid, overresection of the medial eminence, excessive lateral release, overcorrection of IMA
action of lumbricals
flex MTP, extend PIP and DIP
what causes a floating toe deformtiy
plantar translation of the metatarsal head after a distal osteotomy places the intrinsics dorsal to the MTP joint axis so lumbricals extend MTP instead of flex
deformity in hammer toe
PIP flexion
treatment for flexible hammertoe
non op - protective padding, tall-toe box shoes, splints
operative - flexor tenotomy or flexor to extensor tendon transfer
treatment for fixed hammertoe
operative - PIP arthroplasty or arthrodesis
deformity in claw toe
PIP and DIP flexion, fixed MTP hyperextension
operative treatment for flexible claw toe
flexor to extensor tendon transfer of FDL (makes FDL function as an intrinsic), lengthening of EDL and EDB
operative treatment for fixed claw toe
PIP arthroplasty or arthrodesis + MTP joint capsulotomy and extensor lengthening. dislocated MTP requires Weil/distal MT shortening osteotomy to reduce joint
deformity in mallet toe
DIP flexion
treatment for flexible mallet toe
flexor tenotomy
treatment for fixed mallet toe
DIP arthroplasty or arthrodesis
what is the key component of a crossover toe
disruption of plantar plate
which sesamoid is more frequently involved in trauma?
tibial
most common location of interdigital neuroma
interdigital nerve usually between third and fourth MT (where medial and lateral plantar nerves meet)
where does the medial plantar nerve frequently get compressed?
knot of henry (junction of FHL and FDL tendons)
what are the deforming forces in CMT?
PL>TA - first ray plantarflexion, PT>PB - hindfoot varus, extrinsics>intrinsics - claw toe
position for first MTP fusion
neutral rotation, 10-15 degrees dorsiflexion, 5 degrees valgus
position for triple fusion
0-5 degrees hindfoot valgus, neutral abduction/adduction, plantigrade
position for tibiotalar fusion
neutral dorsiflexion, 0-5 degrees hindfoot valgus, 5-10 degrees external rotation
what is a Cotton osteotmy?
plantarflexion osteotomy - dorsal opening wedge of the cuneiform
what is a Dwyer osteotomy?
lateral calcaneal closing wedge osteotomy for hindfoot varus
how do medial talar OCDs differ from lateral?
usually more posterior, larger, deeper, more common
how do lateral talar OCDs differ from medial
usually related to trauma, more central or anterior
structure at risk with anteromedial ankle arthroscopy portal
saphenous nerve and vein
structure at risk with anterocentral ankle arthroscopy portal
DP artery
structure at risk with anterolateral ankle arthroscopy portal
dorsal intermediate cutaneous branch of SPN
structure at risk with posterolateral ankle arthroscopy portal
sural nerve, short saphenous vein
structure at risk with posteromedial ankle arthroscopy portal
posterior tib artery
what tendinous procedures need to be done in a Chopart amputation
tib ant transfer to talar neck and TAL to prevent equinus
what is Bohler’s angle and what’s a normal value?
line from highest point on calc anterior process to highest point on posterior facet, line tangential to superior edge of tuberosity, normal 20-40 degrees
what is the angle of Gissane and what’s a normal value?
angle formed by intersection of a line drawn along the dorsal aspect of the anterior process of the calc and along the dorsal slope of the posterior facet, normal 120-145
most common complication in operative treatment of Morton’s neuroma
formation of stump neuroma
complication in dorsal approach to Morton’s neuroma
failure to excise neuroma
complication in plantar approach for Morton’s neuroma
wound healing problems
anatomy of lisfranc ligament
between medial cuneiform and base of second metatarsal
main blood supply to talar body
artery of the tarsal canal from posterior tibial artery
what is the remaining blood supply in type 2 talar neck fractures
medial from deltoid artery (branch of posterior tibial artery)
what movement stresses the Lisfranc ligament?
pronation and abduction
when is primary arthrodesis indicated in lisfranc injuries?
purely ligamentous high energy injury
what deformity is seen after excision of both sesamoids?
cock up deformity/claw toe
which intrinsic is not innervated by the tibial nerve?
EDB (DPN)
most common complication of medial/tibial sesamoid excision
hallux valgus
nerve injury in lateral/fibular sesamoid excision
first common digital nerve
repair technique for chronic Achilles with 2-5 cm gap
VY lengthening +/- FHL transfer
operative treatment for all stage 2 PTTI
FDL or FHL tendon transfer to navicular
PTTI stage 2a + treatment
arch collapse, flexible hindfoot, normal forefoot. add medial slide calc osteotomy
PTTI stage 2b + treatment
arch collapse, flexible hindfoot, abducted forefoot (>40% TN uncoverage), lateral column lengthening +/- medial calc slide
treatment when forefoot remains supinated in PTTI
Cotton osteotomy (dorsal opening wedge of cuneiform to plantarflex first ray)
stage 3 PTTI + treatment
arch collapse, rigid hindfoot and forefoot, subtalar arthritis. -> triple
hallux valgus treatment when DMAA > 10, IMA < 13, and HVA < 40
distal MT biplanar closing wedge osteotomy
hallux valgus treatment when DMAA > 10 and IMA > 13 or HVA > 40
proximal MT osteotomy and distal MT medial closing wedge osteotomy
what is calcaneus gait
weak toe off and dorsiflexed ankle due to weak GSC
what is steppage gait?
increased hip and knee flexion to clear foot, foot slap, due to weak TA
what is the main muscle action during heel strike?
eccentric contraction of the anterior compartment
what is the main muscle action during foot flat?
eccentric contraction of posterior compartment
what is the main muscle action during toe off?
concentric contraction of the posterior compartment
what is the main muscle action in swing phase?
concentric contraction of the anterior compartment
what ABI is needed for wound healing?
0.45
what absolute toe pressure is needed for healing?
40
what transcutaneous oxygen measurement (PO2) of the toes is needed for healing?
40
what nutritional measurements predict healing?
protein > 6, WBC > 1500, albumin > 2.5
what tendinous procedure needs to be done in a lisfranc amputation?
transfer peroneals to cuboid to prevent varus
what two things are required for a syme amputation?
stable heel pad and patent PT artery
amputation with lowest energy expenditure
TMA
