Ankle Fractures Flashcards
age distribution of ankle fractures
bimodal: young, active male 15-24 and elderly females 75-84
percentage of each fracture type:
70% isolated malleolus fx
20% bimalleolar
7% trimalleolar
what type of ankle fractures are most common?
isolated malleolus
risk factors for ankle fractures
male
younger age
obesity
smoking
alcohol consumption
mechanism of injury most common
twisting injury
associated injuries
open fractures
syndesmotic injury
chondral injury
peroneal tendon tears
most common associated injury
syndesmotic injury
osteology of the ankle
modified hinge joint consisting of tibia, fibula, and talus
3 ligamentous complexes that stabilize the ankle
deltoid
lateral ligament complex
syndesmosis
deltoid two components
superficial & deep
superficial deltoid component extends from______
medial malleolus to broad insertion onto navicular, sutentaculum tali, and talus
extends from medial malleolus to broad insertion onto navicular, sutentaculum tali, and talus
superficial deltoid
deep deltoid extends from_____
medial malleolus to talus
extends from medial malleolus to talus
deep deltoid
resists hind foot eversion
superficial deltoid
superficial deltoid resists what motion
hindfoot eversion
deep deltoid resists what motion
ER of talus
resists ER of talus
deep deltoid
lateral ligament complex 3 components
anterior talofibular ligament (ATFL)
calcaneofibular ligament (CFL)
posterior talofibular ligament (PTFL)
anterior talofibular ligament (ATFL)
calcaneofibular ligament (CFL)
posterior talofibular ligament (PTFL)
lateral ligament complex
primary restraint to anterior displacement, IR, and inversion of talus
anterior talofibular ligament (ATFL)
most frequently injured ligament
anterior talofibular ligament (ATFL)
the ATFL is the primary restraint to ____
anterior displacement, IR, and inversion of talus
calcaneofibular ligament is deep to ______ tendons
peroneal
2nd most commonly injured ligament
calcaneofibular ligament (CFL)
deep to peroneal tendons
calcaneofibular ligament (CFL)
strongest ligament of lateral complex
posterior talofibular ligament (PTFL)
least likely ligament to be disrupted
posterior talofibular ligament (PTFL)
5 components of the syndesmosis
anterior inferior tibiofibular ligament (AITFL)
posterior inferior tibiofibular ligament (PITFL)
intraosseous ligament (IOL)
intraosseous membrane
inferior transverse ligament (ITL)
originates from anterolateral tubercle of distal tibia
anterior inferior tibiofibular ligament (AITFL)
inserts anteriorly onto lateral malleolus
anterior inferior tibiofibular ligament (AITFL)
anterior inferior tibiofibular ligament (AITFL) originates from
anterolateral tubercle of distal tibia
anterior inferior tibiofibular ligament (AITFL) inserts anteriorly onto
lateral malleolus
broad origin from posterior tibia
posterior inferior tibiofibular ligament (PITFL)
inserts onto posterior aspect of lateral malleolus
posterior inferior tibiofibular ligament (PITFL)
strongest component of syndesmosis
posterior inferior tibiofibular ligament (PITFL)
posterior inferior tibiofibular ligament (PITFL) has broad origin from
posterior tibia
posterior inferior tibiofibular ligament (PITFL) inserts onto
posterior aspect of lateral malleolus
distal continuation of interosseous membrane
intraosseous ligament
what neurovascular structures are at risk with anterior approach to the ankle
anterior tibial artery and deep peroneal nerve
anterior tibial artery and deep peroneal nerve are at risk with what approach
anterior
course over anterior ankle between EDL and EHL
anterior tibial artery and deep peroneal nerve
anterior tibial artery and deep peroneal nerve course over
anterior ankle between EDL and EHL
posterior tibial artery and tibial nerve course posterior to
medial malleolus between FDL and FHL
posterior tibial artery and tibial nerve at risk with what approach
posteromedial approach
course posterior to medial malleolus between FDL and FHL
posterior tibial artery and tibial nerve
at risk with posteromedial approach
posterior tibial artery and tibial nerve
superficial peroneal nerve crosses anteriorly over
fibula about distal 1/3
superficial peroneal nerve at risk with what approaches
posterolateral
direct lateral
anterior/anterolateral
crosses anteriorly over fibula about distal 1/3
superficial peroneal nerve
at risk with posterolateral, direct lateral, anterior/anterolateral approaches
superficial peroneal nerve
sural nerve at risk with what approaches
posterolateral and direct approach to fibula
at risk with posterolateral and direct approach to fibula
sural nerve
acts as buttress to prevent lateral displacement of talus
fibula
the fibula acts a buttress to prevent what
lateral displacement of talus
dorsiflexion results in what motion of the fibula
ER and lateral translation
plantar flexion results in narrower, posterior aspect of the talus leading to ____
IR of talus
_____ results in narrower, posterior aspect of the talus leading to IR of the talus
plantarflexion
_____ results in fibula ER and lateral translation, accommodating anteriorly wider talus
dorsiflexion
classification of ankle fractures
lauge-hansen
classification for the location of fibular fractures
danis-weber
what is a supination-adduction ankle fracture
- talofibular sprain or distal fibular avulsion
- vertical medial malleolus and impaction of anteromedial distal tibia
- talofibular sprain or distal fibular avulsion
- vertical medial malleolus and impaction of anteromedial distal tibia
supination-adduction
- anterior tibiofibular ligament sprain
- lateral short oblique fibula fracture
- posterior tibiofibular ligament rupture or avulsion of posterior malleolus
- medial malleolus transverse fracture or disruption of deltoid ligament
supination-external rotation
supination-external rotation type
- anterior tibiofibular ligament sprain
- lateral short oblique fibula fracture
- posterior tibiofibular ligament rupture or avulsion of posterior malleolus
- medial malleolus transverse fracture or disruption of deltoid ligament
- medial malleolus transverse fracture or disruption of deltoid ligament
- anterior tibiofibular ligament sprain
- transverse comminuted fracture of the fibula above the level of the syndesmosis
pronation-abduction
pronation-abduction type
- medial malleolus transverse fracture or disruption of deltoid ligament
- anterior tibiofibular ligament sprain
- transverse comminuted fracture of the fibula above the level of the syndesmosis
- medial malleolus transverse fracture or disruption of deltoid ligament
- anterior tibiofibular ligament disruption
- lateral short oblique or spiral fracture of fibula
- posterior tibiofibular ligament rupture or avulsion of posterior malleolus
pronation-external rotation
pronation-external rotation type=
- medial malleolus transverse fracture or disruption of deltoid ligament
- anterior tibiofibular ligament disruption
- lateral short oblique or spiral fracture of fibula
- posterior tibiofibular ligament rupture or avulsion of posterior malleolus
Danis-weber type A=
infrasyndesmotic
Danis weber type B=
transsyndesmotic
Danis weber type C=
suprasyndesmotic
curbstone fracture=
avulsion fracture of posterior tibia resulting from tripping
avulsion fracture of posterior tibia resulting from tripping
curbstone fracture
AITFL avulsion off anterior fibular tubercle usually seen with SER-type fracture patterns
LeFort-Wagstaffe fracture
LeFort-Wagstaffe fracture
AITFL avulsion off anterior fibular tubercle usually seen with SER-type fracture patterns
AITFL avulsion of anterior tibial margin
Tillaux-Chaput fracture
Tillaux-Chaput fracture
AITFL avulsion of anterior tibial margin
on exam, palpate proximal fibula for ____
Maisonneuve fracture
physical exam:
ecchymosis and swelling around the ankle
deformity
soft tissue assessment
recommended Xray views
ankle series-AP, lateral, mortise
dynamic stress views
full length tibia radiographs
manual stress view is the most appropriate stress radiograph to assess competency of _____
deltoid ligament
Xray findings indicative of syndesmotic injury
decreased tibiofibular overlap
increased medial clear space
increased tibiofibular clear space
decreased tibiofibular overlap
increased medial clear space
increased tibiofibular clear space
syndesmotic injury
normal tibiofibular overlap on AP
> 6 mm
medial clear space of >______ mm with external rotation stress applied to a dorsiflexed ankle is predictive of deep deltoid disruption
5
normal tibiofibular overlap on mortise view
> 1 mm
medial clear space of >5 mm with external rotation stress applied to a dorsiflexed ankle is predictive of____
deep deltoid disruption
normal medial clear space on mortise or stress view
<4 mm
normal tibiofibular clear space on both AP and mortise views
<6 mm
bisection of line through tibial anatomical axis and line through tip of both malleoli
talocrural angle
talocrural angle=
bisection of line through tibial anatomical axis and line through tip of both malleoli
shortening of lateral malleoli fractures can lead to increased ____
talocrural angle
double contour sign
misty mountains sign
spur sign
posterior malleolus fracture
signs suggestive of posterior malleolus fracture
double contour sign
misty mountains sign
spur sign
CT indications
trimalleolar fracture operative planning
assess morphology of posterior malleolus
supination adduction injury
most useful CT views to assess posterior malleolus
axial and sagittal views
CT findings
size and shape of posterior malleolus fragment
entrapped loose fragments
impaction
comminution
MRI indications
evaluate soft tissue or cartilaginous injuries
MRI findings
deltoid injury
syndesmotic injury
lateral ankle ligament complex
peroneal tendon injury
chondral lesions of talus
may be able to bear weight
positive anterior drawer or talar tilt test
XR shows no fracture
ankle sprain
positive Hopkin’s squeeze test
increased medial clear space or tibiofibular diastases on stress view
syndesmotic injury
palpable gap over achilles
inability or weakness with plantar flexion
increased resting dorsiflexion when prone with knees bent
positive Thompsons test
achilles tendon rupture
high energy, axial load
significant articular involvement
chaput fragment, volkmann fragment, medial malleolus, central impaction
pilon fracture
high energy with extensive soft tissue injury
XR shows dislocation of talus from calcaneus or navicular bone
subtalar dislocation
indications for nonoperative treatment
stable ankle fracture
isolated stable medial malleolus fracture
isolated stable lateral malleolus fracture
avulsion tip fractures of medial or lateral malleolus
posterior malleolar fracture with < 25% joint involvement or < 2mm step-off
unfit for surgery
stable ankle fracture op or non op?
non op
isolated stable medial mall op or non op?
non op
isolated stable lateral mall op or non op?
non op
avulsion tip fractures of medial or lateral malleolus op or non op?
non op
posterior malleolar fracture with < 25% joint involvement or < 2mm step-off op or non op?
non op
non op modalities:
CAM boot
short leg splint
short leg cast
ORIF indications
any talar displacement
bimalleolar or bimalleolar-equivalent fracture
posterior malleolar fracture with > 25% or > 2mm step-off
Maisonneuve fracture
Bosworth fracture-dislocations
open fractures
symptomatic malleolar nonunions
any ____ displacement -> ORIF
talar
bimalleolar or bimalleolar-equivalent fracture op or non op?
op
posterior malleolar fracture with > 25% or > 2mm step-off op or non op?
op
Maisonneuve fracture op or non op?
op
Bosworth fracture-dislocations op or non op?
op
open fractures op or non op?
op
symptomatic malleolar nonunions op or non op?
op
goal of treatment is stable anatomic reduction with restoration of ______
mortise
approach options
direct lateral
posterolateral
posteromedial
direct medial
direct lateral approach ->
common approach for fibula ORIF syndesmotic fixation
syndesmotic fixation
common approach for fibula ORIF syndesmotic fixation
syndesmotic fixation
direct lateral approach
posterolateral approach ->
concomitant access to posterior fibula and posterior malleolus
prone or lateral
concomitant access to posterior fibula and posterior malleolus
prone or lateral
posterolateral approach
access to medial malleolus and posterior malleolus
posteromedial approach
common approach for medial malleolus ORIF
direct medial approach
considered most important factor for satisfactory outcome
anatomic reduction
1 mm shift of talus leads to ____% decrease in tibiotalar contact area
42
______ mm shift of talus leads to 42% decrease in tibiotalar contact area
1
worse outcomes associated with:
decreased level of education
smoking
alcohol use
presence of medial malleolar fracture
restoration of ______ in SA ankle fracture leads to optimal functional outcomes
marginal impaction of tibial plafond
improved incisional perfusion with _______ sutures
Allgöwer-Donati
proper braking response time (driving) returns to baseline at _____ weeks after surgery
9
braking travel time is significantly increased until _____ weeks after initiation of weight bearing in both long bone and periarticular fractures of lower extremity
6
indications for ex fix
severe open fractures with gross contamination
poor soft tissue requiring close monitoring
unstable reduction
ex fix has lower risk of ______ versus a splint
redislocation and skin complication
non op indications for isolated medial mall fracture
isolated medial malleolus fracture without talar shift
avulsion tip fracture
non op technique for isolated medial mall fracture
NWB for 4-6 weeks
outcomes of isolated medial mall fracture non op treatment
good outcomes with >95% union rate for isolated injury
indications for ORIF of isolated medial mall fx
any talar shift
ORIF techniques for isolated medial mall fx
lag screw
antiglide plate with lag screw
tension band fixation
lag screw fixation stronger if placed _____
perpendicular to fracture line
antiglide plate with lag screw
best for ______ isolated medial mall fractures
vertical shear
tension band fixation for isolated medial mall is useful when
fragment too small
poor bone quality
non op indications of isolated lateral mall
stable mortise with no talar shift
> ______mm of medial clear space widening on stress views considered unstable in isolated lateral mall fx
4-5
isolated lateral mall non op techniques
immediate WBAT in CAM boot
brief period of immobilization in splint
ORIF indications of isolated lateral mall fracture
presence of talar shift on static or stress view (bimalleolar equivalent)
>3 mm displacement
isolated lateral mall ORIF techniques
plate
retrograde intramedullary fixation
stiffest fixation construct for the fibula is a ____ plate
locking
one-third tubular or anatomic distal fibular plate
stiffest fixation construct for the fibula is a locking plate
lateral plate
one-third tubular plate (antiglide mode)
posterior antiglide plating is biomechanically superior to lateral plate
disadvantage of peroneal tendon irritation if plate too distal
posterolateral plate
when is retrograde intramedullary nailing of isolated lateral mall useful
poor soft-tissue envelopes or high risk for wound-healing complication
what is a bimalleolar equivalent?
DELTOID LIGAMENT TEAR WITH FIBULAR FRACTURE
bimalleolar fracture non op indications
low demand and unable to undergo surgical intervention
ORIF indications in bimalleolar fractures
any displacement or talar shift (static or stress view)
bimalleolar ORIF fibular techniques
lateral plate
posterolateral plate
retrograde intramedullary fixation
bimalleolar fracture medial mall techniques
antiglide plate
tension band wiring
lag screws
posterior malleolus fracture non op indications
< 25% of articular surface involved
size should be calculated on CT since plain radiographs are unreliable
< 2 mm articular stepoff
stable syndesmosis
ORIF indications of posterior malleolus fracture
> 25% of articular surface
2 mm articular stepoff
syndesmotic instability
posterior subluxation of talus
ORIF posterior mall approaches
posteromedial
posterolateral
percutaneous
interval for posterolateral approach to isolated medial mall
between FHL and peroneal tendons
posterior malleolus fixation methods
antiglide plate
percutaneous A to P lag screws
stiffness of syndesmosis restored to ________% normal with isolated fixation of posterior malleolus vs 40% with isolated syndesmosis fixation
70
_____ may remain attached to posterior malleolus and syndesmotic stability may be restored with isolated posterior malleolar fixation
PITFL
stress examination of _______ still required after posterior malleolar fixation
syndesmosis
40-90% of distal third spiral tibia fractures have an associated ______ fracture
posterior malleolus
40-90% of _______ fractures have an associated posterior malleolus fracture
distal third spiral tibia
rare fracture-dislocation of ankle where fibula is entrapped behind tibia and is irreducible
Bosworth fracture dislocation
what is a Bosworth fracture
rare fracture-dislocation of ankle where fibula is entrapped behind tibia and is irreducible
Bosworth fracture treatment
ORIF
posterolateral ridge of the distal tibia hinders reduction of the fibula
Bosworth fracture dislocation
fracture-dislocation of the ankle due to hyperplantarflexion
hyperplantarflexion variant
main feature is a vertical shear fracture of the posteromedial tibial rim
hyperplantarflexion variant
hyperplantarflexion variant main feature
vertical shear fracture of the posteromedial tibial rim
“spur sign” is pathognomonic
hyperplantarflexion variant
hyperplantarflexion variant pathognomonic feature
spur sign
double cortical density at the inferomedial tibial metaphysis
spur sign
what is the spur sign?
double cortical density at the inferomedial tibial metaphysis
hyperplantarflexion variant treatment
ORIF of posterior malleolus with antiglide plating
open ankle fracture operative options
emergent operative debridement and ORIF
ex fix
open ankle fracture ex fix indications
significant soft tissue compromise
unstable fracture in splint/cast
_____% of all ankle fractures have associated syndesmotic injury
10%
higher incidence with higher fibula fractures
syndesmotic injury
syndesmotic injury higher incidence with _____ fractures
higher fibula
fixation of associated syndesmotic injury usually not required when fibula fracture within ______ cm of plafond
4.5
Weber A fracture has <______% associated syndesmotic injruy
10
Weber B fracture has ______% associated syndesmotic injury
40-50%
Weber C fracture has ______% associated syndesmotic injury
> 80%
static views of ankle with associated syndesmotic injury shows what?
tibiofibular clear space
tibiofibular overlap
medial clear space
dynamic views of syndesmotic injury
gravity stress
manual external-rotation stress
cotton/hook test
how do you get a manual external-rotation stress view?
abduction/external rotation stress of dorsiflexed foot
instability of the syndesmosis is greatest in the _______ direction
anterior-posterior
how to get a gravity stress test
patient placed in lateral decubitus position
similar effectiveness to manual ER stress test
how to get a cotton/hook test?
intraoperative assessment
bone hook around fibula used to pull while placing counter traction on tibia
intraoperative assessment
bone hook around fibula used to pull while placing counter traction on tibia
cotton/hook test
treatment of syndesmotic injruy
syndesmotic screw or suture fixation
indications for syndesmotic screw fixation of associated syndesmotic injruy
widening of medial clear space
tibiofibular clear space (AP) greater than 5 mm
tibiofibular overlap (mortise) narrowed
syndesmotic fixation: length and rotation of _____ must be accurately restored
fibula
“Dime sign”/Shentons line to determine ______
length of fibula
syndesmotic fixation outcomes are strongly correlated with ______
anatomic reduction
syndesmotic fixation: placing reduction clamp on _______ (1-2 cm proximal to mortise) will achieve reliable anatomic reduction
middle medial tibial ridge and the lateral fibular ridge at the level of the syndesmosis
syndesmotic fixation: one or two cortical screw(s) or suture-button devices 2-4 cm above joint angled posterior to anterior _______ degrees (fibula posterior to tibia)
20-30
suture button or screws have lower rate of malreduction and reoperation rate in syndesmotic fixation?
suture button
syndesmotic screws should be maintained in place for at least ____ weeks
8-12
syndesmotic injury post op: must remain _____, as screws are not biomechanically strong enough to withstand forces of ambulation
non weightbearing
any postoperative malalignement or widening after syndesmotic fixation should be treated with
open debridement, reduction, and fixation
diabetic ankle fracture pathophysiology
poor circulation impairs wound and fracture healing
loss of protective sensation
poor bone quality
non op management of ankle fractures in diabetic patients can lead to what complications
loss of reduction (greatest risk)
Charcot arthropathy
malunion
nonunion
non op indications for diabetic ankle fractures
stable isolated unimalleolar fracture
risks of operative treatment of diabetic ankle fractures
prolonged healing
high risk of hardware failure
high risk of infection
lower functional outcomes
need for future amputation
how to enhance fixation in diabeticc ankle fractures
multiple quadricortical syndesmotic screws (even in the absence of syndesmotic injury)
tibiotalar Steinmann pins or hindfoot nailing
ankle spanning external fixation
augment with intramedullary fibula K-wires
stiffer, more rigid fibular plates
maintain non-weightbearing postop ankle fractures in diabetics for ____ weeks
8-12 weeks
how long to maintain non weight bearing in diabetics versus normal patients
8-12 weeks in diabetics vs 4-8 weeks in normal patients
complications of non op ankle fracture management
ulceration from cast
delayed union or nonunion
malunion
post-traumatic arthritis
DVT (5%)
ankle stiffness
complications of operative management of ankle fractures
wound problems (~5%)
deep infections (1-2%)
post op stiffness
posttraumatic arthritis
neurologic injury
hardware irritation
complex regional pain syndrome
deep infections occur in diabetic patients up to ____%
20
largest risk factor for deep infections in diabetic patients is presence of ______
peripheral neuropathy
_______ of tibial plafond in SAD injuries should be addressed at time of surgery
articular impaction
post-operative stiffness-can have
loss of dorsiflexion with _____ fixation
posterior
post traumatic arthritis very common in _____ type injuries
log splitter in which trans-syndesmotic fracture-dislocations in which the talus is driven into the distal tibiofibular articulation)
log splitter injuries aka trans-syndesmotic fracture-dislocations in which the talus is driven into the distal tibiofibular articulation) are associated with what complication
posttraumatic arthritis
At risk with lateral approach to distal fibula, posterolateral, and anterior/anterolateral approaches
superficial peroneal nerve
risk factors for hardware irritation
younger age
women
longer operative time
posterolateral plating of fibula
risk factors
distal placement of fibula plate
protruding screw head in most distal hole of fibula plate
peroneal tendonitis
risk factors for peroneal tendonitis
distal placement of fibula plate
protruding screw head in most distal hole of fibula plate
at risk with posterior medial malleolus screw placement
posterior tibial tendonitis
risk for posterior tibial tendonitis
posterior medial mall screw placement
risk factors for adverse outcomes
older age
osteoporosis
diabetes
peripheral vascular disease
female
higher ASA
smoking
alcohol use
lower level of education
positive predictors for good outcomes
age <40
male
ASA 1 or 2
absence of diabetes
