imaging interp 2 foot and ankle

what is the most common location of degenerative joint disease in the foot and ankle

first metatarsal phalangeal joint

what can degenerative joint disease in the first metatarsal phalangeal joint result in

hallux valgus deformity

what causes hallux rigidus syndrome

degenerative changes with associated dorsal osteophyte causing pain

pressure from shows

loss of motion at first metatarsal phalangeal joint

what kind of deformity can be seen with degenerative joint disease and a hallux valgus deformity of the first metatarsal phalangeal joint

bunion deformity

is the ankle a common site for degenerative joint disease

no

usually secondary to trauma or other pathological processes

what is coalition of the tarsals associated with

degenerative joint disease in the mid//hind foot

what are the radiographic features associated with degenerative joint disease in the foot/ankle

early on nonuniform loss of joint space

subchondral sclerosis

subchondral cysts

osteophytes

thickening of lateral cortex of distal first metatarsal

what are the general features of rheumatoid arthritis in the ankle/foot

changes in both the feet and hands

bilaterally symmetrical

what are the radiographic features of rheumatoid arthritis in the ankle/foot

primarily affects the metatarsal joints and proximal interphalangeal joints (spares DIPS)

affects first IP and fifth MTP then works back from 5th digit

fibular deviation of the digits at MTP

retrocalcaneal bursitis w/ adjacent bony erosion

plantar fasciitis

does rheumatoid arthritis affect the DIPS

not usually

what is the appearance of rheumatoid arthritis in the foot/ankle when it is affecting first IP and 5th MTP and working back towards first digit

periarticular osteopenia

marginal erosions (more prominent medial except 5th MTP head)

uniform loss of joint space

what is a fibular deviation of the digits at the MTP called

lanois deformity

what are the general features of psoriatic arthritis

feet affected in a similar fashion as the hands

may see ray pattern

diffuse soft tissue swelling (sausage finger)

what are the psoriatic arthritis radiographic features

swelling, erosion, periostitis

osteolysis, metatarsal heads, distal tufts (pencil in cup)

achilles, plantar inserts get erosions

asymmetric erosive arthropathy w/ boney proliferation

DIP>PIP>MCP

tuft changes, resorption of sclerosis, may result in ivory phalanx

what can the appearance of psoriatic arthritis be if there is swelling, erosion, and periostitis

juxta-articular bone density often normal

may demonstrate generalized osteopenia from disuse

what are the general features of gout

males over 40

asymmetric

starts monoarticular progresses to periarticular over time

most commonly involved 1st MTP joint

what are the radiographic features of gout

juxta-articular erosions

no joint space narrowing until late in disease

soft tissue masses

no juxta-articular osteopenia

what are the general features of neuropathic arthropathy

destructive articular disease secondary to a loss or impairment in joint proprioception

hypertonic pattern or mixed hypertrophic/atrophic most common in ankle and foot

what causes neuropathic arthropathy

diabetes

syringomyelia

amyloidosis

alcoholism

syphilis

leprosy

what are the 6Ds of hypertrophic pattern

dense bone

debris or loss bodies

destruction of articular cortex

disorganization of joint

dislocation

distension of joint

what are the basic classifications of ankle/foot trauma

unimalleolar

bimalleolar

trimalleolar

how can stability of ankle injuries be thought of

as a ring

formed by talus, tibia, fibula, and connecting ligamentous structures

single break in ring is stable

more than one breaks in the ring is unstable

how can ligamentous stability be assessed on radiographs

stress views

what is a cotton fracture

trimalleolar fractures

what are pott’s and dupuytrens fractures

(terms are labeled as obsolete in slidesbut it was included in lecture?)

distal fracture typically 2-3 inches proximal to distal tip of fibula

disruption of distal tibial/fibular syndesmoses

not used to describe bimalleolar fractures

why are the potts and dupuytrens fractures seem to be the source of confusion

assocaited disruption of the deltoid ligament resulting in lateral displacement of the talus

what is a maisonneuve fracture

fracture of proximal fibula with complete tear of distal tibial fibular syndesmoses and interossesous ligament

could also be a fracture of the medial malleolus

what is a possible reason why a maisonneuve fracture could be missed

patients often complain of severe ankle pain so the proximal fibular fracture is missed

what is a pilon fracture

fracture of tibial plafond due to compressive forces

usually accompanie other fractures

what is a tillaux fracture

avulsion of a fragment of bone at tibial attachment of anterior tibiofibular ligament

if a tillaux fracture occurs in an adolescent what is it

type 3 salter harris injury

during what stage of the lauge-hansene classification can a tillaux fracture occur

stage 1 SER

what are the planes associated with a triplane fracture

transverse fracture- through growth plate of dist tibia

sagittal fracture- through epiphyses

coronal fracture- distal posterior tibial metaphysis

what are weber and lauge hansen classifications based on

location of fibular fracture in relation to ankle mortise joint

the higher it is the worse the prognosis

what is a limitation of the weber and lauge-hansen classifications

doesn’t address MOI hence association of other fractures

what does the first term describe in the lauge-hansen classification system

position of foot in relation to leg

what does the second term describe in the lauge-hansen classification system

motion of talus relative to the leg

what is SER and what percent of ankle fractures is it responsible for

supination-external rotation

60% of ankle fractures

what is SAD and what percent of ankle fractures is it responsible for

supination-adduction

20% of ankle fractures

what is PER and what percent of ankle fractures is it responsible for

pronation-external rotation

20% of ankle fractures when combined with PAB

10% alone

what is PAB and what percent of ankle fractures is it responsible for

pronation-abduction

20% of ankle fractures when combined with PER

10% alone

what is PDF and does it commonly occur

pronation-dorsiflexion

rare

what is a metatarsal fatigue fracture called

march fracture

what bones are commonly invovled in a march fracture

2nd and 3rd metatarsals

what are metatarsal fatigue fracture radiographic features

focal cortical thickening/solid periosteal reaction

may progress to outright fracture

usually invovles mid to distal shaft

what is a lisfranc fracture

fracture dislocation of metatarsal heads

what is the MOI of a lisfranc fracture

plantar hyperflexion w/ forced supination or pronation

forced abduction of forefoot

what is the 2nd metatarsal head key for

proper location of the remainder of metatarsals

what are the radiology fractures of a lisfranc fracture

medial aspect of 2nd metatarsal align with medial aspect of current cuneiform

homolateral or divergent patterns of metatarsal displacement

amount of displacement does not correlate with severity of injury or symptoms

what is cellulitis usually

result of stasis ulcers and vascular insufficiency

complication of diabetes mellitus

what are teh general features of osteomyelitis/septic arthritis

usually result from cellulitis spread

complication of diabetes mellitus

septic arthritis starts monoarticular but spreads to become polyarticular

what are the general features of regional osteoporosis

loss of bone density confined to a region

what are the 3 main causes of regional osteoporosis

disuse

complex regional pain syndrome (RSDS, sudecks, causalgia)

transient regional osteoporosis of hip/regional migratory osteoporosis

what are the radiographic features of regional osteoporosis

aggressive regional osteopenia

cortical tunneling

irregular endosteal/periosteal resorption

spotty and/or band-like bone loss

what are the general features of freiberg disease

affect metatarsal heads, most commonly 2nd

13-18 year olds, females more common that males

usually secondary to trauma

what are the radiographic features of freiberg disease

flattened

irregular

sclerotic metatarsal head