Flashcards in AVN Deck (67):
What part of a long bone is likely to be affected by AVN?
Epiphysis (try to remember that suppurative infection SPARES the epiphysis)
What specific bone of the bone is more likely to develop AVN?
Femur head and humeral head
What are some synonyms for AVN?
Osteonecrosis, ischemic necrosis, osteochondrosis
When does epiphyseal necrosis become clinically evident?
With articular surface collapse
What is the clinical latent period of AVN?
Weeks to a year
What is the most common etiology category for AVN?
Spontaneous/idiopathic (others include surgery, trauma, alcoholism, corticosteroid usage)
What causes AVN?
Obstruction of extra- and intraosseous vessels by arterial embolism, venous thrombosis, traumatic disruption, or external compression
What is the time frame from initial infarction to healed deformity for AVN?
What causes of AVN fall under the etiology category of external vessel compression?
Trauma, steroids, infection, gaucher's disease, hyperlipidemia
What causes of AVN fall under the etiology category of vessel wall disorders?
RA, LE, radiation, polyarteritis nodosa
What causes of AVN fall under the etiology category of thrombo-embolic disorders?
Alcoholism, steroid, trauma, sickle-cell, caisson's
What is caisson's disease?
What are the four stages of AVN?
Avascular, revascularization, repair, deformity
What happens in the avascular stage of AVN?
Obliteration of epiphyseal blood supply, altered growth, altered cartilaginous growth
The altered cartilage seen with AVN can lead to what further condition?
Most X-ray findings of AVN are seen during which stage?
What is the term for when deposition occurs and new bone is deposited directly on dead bone therefore thickening the trabeculation and increasing bone density with AVN during the revascularization phase?
What is the radiographic sign that is definitive for AVN?
What is the best procedure of choice to diagnose AVN?
During which phase of AVN can we see the mushroom deformity and sagging rope sign?
What is the major factor in residual deformity following AVN?
How much compressive force is exerted on the necrotic bone during revascularization and repair phases
What is the trabecular pattern seen with AVN?
Mottled appearance: thickened irregular pattern traversing the necrotic areas usually in revascularization and repair phases
What is the name of the condition of AVN in the adult femoral head?
What is most likely the condition at hand with BILATERAL C-shaped lesions all over the distal femur and proximal tibia?
Metaphyseal/diaphyseal infarcts from AVN
What is the gender and age bias for Chandler's disease?
Males ages 30-70
What is the radiographic sign of a necrotic area that tends to be wedged or semilunar shaped with a central apex seen in Chandler's disease?
What are the radiographic signs of AVN?
Snow cap sign, crescent/rim sign, mushroom deformity, hanging rope sign
What imaging study is best to visualize AVN?
What is the condition of AVN of the femoral capital epiphysis before closure?
What is the age and gender bias for Legg-Calve-Perthes Disease?
Males 4-8 YOA
Which ROM are commonly decreased with LCPD?
Abduction and internal rotation
Where is the referred pain in kids with LCPD?
What is unique about the joint space of LCPD?
INCREASED joint space (Kohler's teardrop)
What are the 3 major radiographic findings associated with LCPD?
Soft tissue swelling, small epiphysis, lateral displacement of ossification center
When gender has a worse prognosis with LCPD?
What is osteochondritis dissecans?
Focal subchondral infarction of sub-articular bone
What is the age and gender bias for osteochondritis dissecans?
Males 11-20 YOA
What is the most common location for osteochondritis dissecans?
Osteochondritis will lead to what other condition later on?
What is the specific location of the knee commonly affected by osteochondritis dissecans?
Lateral margin of medial femoral condyle (intracondylar tunnel)
What is the term for osteochondritis dissecans of the capitulum of the elbow?
What is the second most common location for osteochondritis dissecans besides the knee?
What type of injury/alternative name is Osgood Schlatter's Disease?
AKA traction apophysitis
When Osgood Schlatter's Disease also involves the inferior pole of the patella, what is it then called?
Sindig-Larsen-Johanssen disease (ridiculous)
What is the gender and age bias for Osgood Schlatter's Disease?
What is the mechanism of injury for traction apophysitits?
When do the symptoms of localized pain, tenderness, and soft tissue swelling over the tibial tubercle with Osgood's go away?
By 18 YOA
What condition may be related to wearing high heels and involves AVN of the second metatarsal head?
What's the gender and age bias for Freiberg's disease?
What condition represents AVN of the lunate?
What is the gender and age bias for Kienbock's disease?
What usually causes AVN of the lunate?
Kienbock's disease is usually associated with what other radiographic finding?
Negative ulnar variance (75%)
What condition is AVN of the navicular bone?
Is Scheuermann's disease really AVN?
Probably not (likely trauma abnormality of the discovertebral junction)
What age group is usually affected by Scheuermann's disease?
What's another name for Scheuermann's?
Juvenile discogenic disease
What are the signs and symptoms of juvenile discogenic disease?
Chronic back pain, deformity, early DDD
How many contiguous vertebrae must be affected to diagnose juvenile discogenic disease?
3 Schmorl's nodes in a row
What appears to be the cause of juvenile discogenic disease?
Failure of embryologic vascular channels, centrum defects, and notochord clefts to disappear leaving endplate defects
How common is Scheuermann's disease?
20-40% of those presenting to MRI with back pain have it
What condition represents sclerosis and fragmentation of the calcaneal apophysis but it NOT technically a necrosis?
What is Sever's disease without the presence of pain?
A normal varient (pain must be present for Sever's!)
Calcified medullary infarct could be confused with which bone cancer?
Enchondroma or chondrosarcoma
Calcified medullary infarct is usually associated with what other condition?
How can we differentiate between calcified medullary infarct of the proximal humerus and a chondrosarcoma?
Chondrosarcoma would present with pain; calcified medullary infarct would be asymptomatic