Radiology (Quiz 3)

Question 1

Femoral Neck Fracture

Answer 1

• occur most commonly in subcapital region
• associated with postmenopausal osteoporosis
• avascular necrosis of femoral head is a complication

Question 2

Posterior Hip Dislocation

Answer 2

• more than 90% of hip dislocations
• MOI: high energy trauma (knees impact dashboard)
• sciated nerve may be injured as well

Question 3

Radiographic featurs of posterior hip dislocation

Answer 3

1. Femoral head lateral and superior to the acetabulum
2. fracture of the posterior rim of the acetabulum in most cases
3. femur in internal rotation and adduction
4. affected femoral head may appear smaller secondary to magnification

Question 4

Sacral Fracture

Answer 4

• commonly missed
• vertical or transverse fracture possible
• most commonly both sacroiliac joints are distrupted, the pubic symphysis is separated and the sacrum is fractured

Question 5

Malgaigne Fracture

Answer 5

• articualr or para-articular fracture of the sacroiliac joint and ipsilateral ischiopubic rami
• unstable pelvis
• shortening of ipsilateral lower extremity

Question 6

Patellar Fracture

Answer 6

• can be caused by direct trauma
• best seen on a sunrise or merchants view

Question 7

Transverse Avulsion Patellar Fracture

Answer 7

• caused by indirected force generated by the quadriceps tendon
• much more common than longitudinal or comminuted fractures

Question 8

Lateral Patellar Dislocation

Answer 8

• most dislocations are in this direction
• typically the result of acute injury

Question 9

Tibial Plateau Fracture

Answer 9

• fender or bumper fracture
• most common fracture sustained at the proximal tibia
• associated with damage to ACL, MCL, and medial meniscus
• posttraumatic arthritis and malunion can result

Question 10

Proximal Tibial Stress Fracture

Answer 10

appears as a band of sclerosis in the proximal tibia on plain film

Question 11

Segnod Fracture

Answer 11

• avulsion of lateral tibia at the attachment of the lateral capsule
• varus stress and internal rotation of the leg that occur when knee is flexed place excess tension on the lateral capsule
• ACL tears are commonly associated

Question 12

Ankle Joint Effusion

Answer 12

• seen as fluid density semicircle anterior to the talotibial joint on the lateral view

Question 13

Calcaneal Fracture

Answer 13

• lovers fracture
• boehler’s angle less than 20 deg
• important to determine whether the fracture line involves subtalar joint
• can be associated with spinal compression fractures and fractures of femoral necks and tibial plateaus

Question 14

Talo-Calcaneal Coalition

Answer 14

• one of most common forms of tarsal coalition
• union of two or more bones that are not normally fused
• very rare and non traumatic

Question 15

Tillaux Fracture

Answer 15

• lateral margin avulsion of distal tibia
• results from injury involving a combinatino of abduction and external rotation
• look for vertica fracture line extending from the distal articular surface upward to lateral cortex of tibia

Question 16

Maisonneuve Fracture

Answer 16

• fracture of the proximal half of the fibula
• results from strong eversion at the ankle joint
• when fracture is more proximal: greater damage to interosseous membrane

Question 17

Jones Fracture

Answer 17

• fracture at base of 5th met
• if not immoblized nonunion may be a complication

Question 18

Lisfranc Injury

Answer 18

• fracture or dislocation at tarsometatarsal joint
• most common mechanism of injury is MVA or mountain bikers who get their feet caught in pedal clips

Question 19

What is the best type of image to evaluate a complex pelvic injury

Answer 19

CT

Question 20

Areas that are high risk for stress fractures

Answer 20

• weight bearing bones of lower extremity espcially the lower leg and the foot
• femoral neck
• transverse patellar fracture
• midshaft anterior tibial
• medial malleolus
• talus
• tarsal navicular
• 5th met
• sesamoid great toe

Question 21

TRUE OR FALSE
Developmental Hip Dysplasia occurs more often in males than females and in the left hip as opposed to the right hip.

Answer 21

FALSE

females more than males

Question 22

Developmental Dysplasia of Hip

Answer 22

• recurrent subluxation or dislation of hip secondary to acetabular dysplasia, abnormal ligamentous laxity or both
• early diagnosis is important

Question 23

Radiograph features of DDH

Answer 23

• shallow acetabulum
• acetabular angle greater than 30 degrees
• small capital femoral epiphysis
• delayed ossification of femoral head
• shenton’s curve
• femoral head lateral to perkins line
• femoral head superior to hilgenreiners line

Question 24

Proximal Femoral Focal Deficiency

Answer 24

• congenital disorder consisting of variable degrees of hypoplasia
• varus deformity and shortened limb
• associated findings include ipsilateral fibular hemimelia (absent fibula) and foot deformity

Question 25

Septic arthritis

Answer 25

• most common in infants and teens
• occurs from infectious extension from adjacent metaphysis
• staphylococcus aureus > Group A streptococci are most common etiologic agents
• asymmetric widening of hip joint spaces

Question 26

Toxic Synovitis

Answer 26

• diagnosis of exclusion
• commonly in children under 10 with no limping and no pain in palpation
• positive joint effusion that is negative for organisms on aspiratiosn that resolves with the rest

Question 27

Legg-Calve-Perthes Disease

Answer 27

• idiopathic avascular necrosis of femoral head
• 5-8 who present with knee or hip pain
• men affected more than girls 5:1