Radiology 2B Week 8

What is the most commonly fractured tarsal?

Calcaneus

What are the functions of the calcaneus?

Bear weight

Serve as a springboard for locomotion

What % of calcaneus fractures involve the processes of the bone?

25%

What % of calcaneus fractures involve the subtler joint and body of calcaneus?

75%

What are the two basic types of calcaneus fracture?

Compressive

Non-compressive

What is the MOIs of compressive calcaneus fracture?

Acute and stress

What is the MOI of non-compressive calcaneal fracture?

Avulsive

What is the most common mechanism of calcaneal compression fracture?

Falling from a height and landing on the feet

What % of compressive calcaneal fracture are bilateral?

10%

What is the normal value of bohler's angle?

28-40 degrees

T or F: smaller decrease in bohler's angle produces a better prognosis

True

What condition is associated with avulsion of the calcaneal tuberosity?

Diabetic peripheral neuropathy

What is the second most commonly fractured tarsal?

Talus

What is the most common talar fracture?

avulsion fracture of the anterior surface of the taller neck at the capsular insertion

How are talar fractures classified?

According to anatomical site

What type of fracture occurs at the talar dome?

osteochondral defects

What type of fracture occurs at the talar body?

Transverse or oblique plane via inversion/eversion

What type of fracture occurs at the talar neck?

"aviator" fracture

What complication occurs from aviator fracture?

AVN

T or F: the Talar head is commonly fractured

False

What is the most common fracture of navicular?

Avulsion at dorsum

What is the Ddx of navicular avulsion fracture?

os supranaviculares

What is the most common cuneiform fracture?

Involved in lisfranc (tarsometatarsal) fracture / dislocation

T or F: Isolated cuneiform fracture is rare

True

T or F: Isolated cuboid fracture is common

False (unusual)

What is the Ddx of cuboid fracture?

accessory ossicles:

os peroneum

os versalium

What is the MOI of aviator fracture and talar neck avulsion fracture?

Severe dorsiflexion

What is the MOI of navicular avulsion?

Plantar flexion

What is the term for reabsorption of the talar dome following a talar neck fracture?

Hawkin's sign (the opposite of AVN)

T or F: Hawkin's sign following a talar neck fracture gives a better prognosis

True

What is the most common MOI of metatarsal fracture?

Dropped heavy objects

What part of the metatarsal's most commonly fractured?

Neck or shaft

Which metatarsals are most commonly fractured?

2nd and 3rd

What are the potential lines of metatarsal fracture?

Oblique

Spiral

Transverse

What is the term for stress fracture of the metatarsal due to increased usage?

March fracture

What demographic is march fracture found in?

Runners (who have just drastically increased their milage)

What does a vertical lucency of the 5th metatarsal styloid indicate?

Normal apophysis

What is the term for an avulsion fracture of the 5th metatarsal styloid, through the articular surface?

Dancer's fracture

What is the term for a fracture of the 5th metatarsal at the metadiaphysis, just distal to the articular surface?

Jone's fracture

What is the most common complication of Jone's fracture?

Non-union of the 5th metatarsal

What is the most common injury of the foot?

Dancer's fracture

What is the MOI of dancer's fracture?

Traction of the peroneus brevis tendon during inversion and plantar flexion?

What is the Ddx of dancer's fracture in children?

longitudinally oriented apophysis

What is the most common location of a crush injury in the foot?

Distal phalanx

What is the most common complication of crush injury of the toe?

Nailbed death

What is the MOI of bedroom fracture?

Direct blow to bare toe

What part of the foot is affected by bedroom fracture?

Proximal phalanx

What is the MOI of chip fracture of the phalangeal articular surface?

Hyperflexion/hyperextension of the foot

What is the most common tarsal to dislocate?

Talus

Which joints of talus can become dislocated?

Talotibial

talocalcaneal (subtalar)

talonavicular

What is the most common complication of talus dislocation?

AVN

What is the term for mid-tarsal fracture/dislocation?

Chopart's dislocation

What joints are affected by chopart's dislocation?

talonavicular and calcaneocuboid joints

T or F: Chopart's dislocation is common for the ankle

False (rare)

What is the lisfranc articulation?

Tarsometatarsal junction

What is the direction of lisfranc dislocation?

Dorsal dislocation of metatarsal bases

What is the most common location of lisfranc dislocation?

second metatarsal

What direction of displacement can occur along with lisfranc dislocation?

lateral displacement

What modality is best for viewing lisfranc dislocation?

CT

What fractures commonly accompany lisfranc dislocation?

base of 2nd metatarsal

lateral cuboid surface

What condition is associated with lisfranc dislocation?

Secondary osteoarthritis

What are the most common causes of lisfranc dislocation?

MVAs

Industrial accidents

Equestrian accidents

T or F: Diabetes can cause lisfranc dislocation

True

What % of all traumatic fractures have an associated rib fracture?

10%

What views should be used to visualize rib fracture?

AP and Oblique views

What % of rib fractures go undetected on x-ray?

50%

What is the best modality for visualizing rib fractures?

Ultrasound

Which modality is best for medicolegal purposes in rib fracture?

Bone scan

What is the orientation of rib fracture line?

Transverse or oblique

What is the Ddx of rib fracture on x-ray?

Bronchial shadow

What is the term for a sharp step effect with rib fracture?

Cortical offset

What is the name sign of a hook-like sharp deviation at the distal end of the rib?

Costal hook sign

What does costal hook sign indicate?

Flail segment

What is the term for localized hematoma displacing the pleura inward in rib fracture?

Pleural deflection

What is the name sign of pleural deflection on x-ray?

Extrapleural sign

What is the term for 2 fractures of the same rib?

Flail chest

What is the most common cause of extra pleural sign?

metastatic disease of the ribs

What is the Ddx of rib fracture in children?

Non-accidental trauma (child abuse)

T or F: The upper 3 ribs common fracture

False (rarely)

What rib can be fractured in weightlifters when doing very heavy bench press?

2nd

What type of athletes can develop stress fracture of rib 1?

Throwing athletes

What structures can be impacted by upper rib fractures?

trachea

aorta

great vessels

brachial plexus

spine

Which ribs are most commonly fractured?

Ribs 4-9

What complication can result from anterior fracture of the middle to lower ribs?

spleen and liver rupture

What is the term for abrupt termination of a golf swing when striking the ground, causing a fracture at the lateral margin of the rib?

Golfer's fracture

What is the term for fracture caused by an aggressive hug in elderly people?

Passion fracture

What is the term for isolated rib fragments moving in opposite directions when breathing?

Paradoxical breathing

How many ribs are usually involved in flail chest?

3 or more (not normally isolated)

What must be evaluated in the (unlikely) event of lower rib fracture?

Kidneys

What is the term for stress fracture of the lower anterior ribs due to coughing?

Post-tussive fracture

Which ribs are most commonly affected by post-tussive fracture?

6-7th

What is necessary to view costal cartilage injuries?

Nuclear bone scan

Which joint of the sternum is most commonly fractured?

Manubriosternal junction

What is the orientation of sternum fracture?

Transverse

What imaging modality is most sensitive for sternum fracture?

Ultrasound

What imaging modality is most commonly used in clinical situations of sternal fracture because it best demonstrates degree of displacement?

Plain film X-ray

What fracture is often associated with sternal fracture?

Thoracolumbar compression

What are the potential pleural complications of sternum fracture?

Traumatic pneumothorax

Hemothorax complications

Chylothorax complications

What are the finding soft hemothrax on x-ray?

blunt costophrenic sulci

widening of the paraspinal space

apical "capping"

What compilation of the lung often accompanies sternum fracture?

Pneumonia