2. Osteoporosis, Osteopenia, AVN Flashcards
Osteopenia
This just means increased lucency of bones
Osteomalacia
soft bone from excessive uncalcified osteoid
related to vitamin D issues (either renal causes, liver causes, or other misc causes)
you should think about 4 things:
Ill-defined trabeculae.
Ill-defined corticomedullary junction
bowing
“Looser Zones.”
Looser Zones;
wide lucent bands that transverse bone at right angles to the cortex
These things can happen in lots of different locations - but the classic two:
femoral neck and the pubic rami.
+ sclerosis surrounding the lucency.
You should think two things: osteomalacia and rickets.
they are a type of insufficiency fracture.
Osteoporosis
Low bone density - peaks around 30 and decreases
Causes: Age is the big one. Medications (steroids, heparin, dilantin). Endocrine issues (cushings, hyperthryoidism), Anorexia, and Osteogenesis Imperfecta.
Complications: Fractures -
Most commonly of the spine
2nd most common is the hip,
3rd most common is the wrist
Reflex Sympathetic Dystrophy (RSD)
'’Complex Regional Pain Syndrome”
'’Sudeck Atrophy”
history of trauma or infection.
Some people say it looks like unilateral RA, with preserved joint spaces.
Hand and shoulder are the most common sites of involvement.
Transient osteoporosis of the hip
Female + 3rd trimester + LEFT hip
Men = bilateral
Plainfilm shows osteopenia, MRl shows Edema, Bone scan shows increased uptakefocally.
Regional migratory osteoporosis
Idiopathic
history of pain in a joint, which gets better and then shows up in another joint
On radiograph, transient osteoporosis and AVN look totally differen
Transient Osteoporosis is super lucent - so lucent that sometimes you can barely see the femoral head.
AVN on the other hand, will have patchy areas of sclerosis.
Transient Osteoporosis VS AVN vs Insufficiency Fx on MRI
if these assholes want to take it to the twilight zone, they can add “insufficiency fracture” to the list of distractors. This is really a dirty trick as both Transient Osteoporosis and AVN are susceptible to this. The distinction is that this fracture line should be less serpiginous and instead parallel the subchondral bone o f the femoral head.
Osteoporotic Compression Fracture
Super Common.
“band like” fracture line - which is typically T1 dark (T2 is more variable).
The non deformed portions of the vertebral body should have normal signal. Look also for retropulsion of posterior bone fragments.
Neoplastic Compression Fracture
Most vertebral mets don’t result in compression fracture until nearly the entire vertebral body is replaced with tumor.
If you see dark stuff - it might just be red marrow. BUT if it is darker than the adjacent (normal) disc, you have to assume that it’s a bad thing.
Look at the rest of the spine - mets are often multiple.
Osteoporotic Fx Vs NeoplasticFx
The Osteoporotic Fracture would have a T1 dark line.
The Neoplastic Fracture would be diffusely low T1 signal and blobby
Osteochondritis Dissecans (OCD)
aseptic separation of an osteochondral fragment which can lead to gradual fragmentation of the articular surface and secondary OA.
secondary to trauma, although it could also be secondary to AVN.
Classic locations include the femoral condyle (most common site in the knee), patella, talus, and capitellum.
Osteochondritis Dissecans (OCD) Staging
Stage 1: Stable - Covered by intact cartilage, Continuous with host bone
Stage 2: Stable on Probing, Partial discontinuity with host bone
Stage 3: Unstable on Probing, Complete discontinuity of lesion.
Stage 4: Dislocated fragment
Osteochondritis Dissecans (OCD) population and location
< 18
Most common in the lateral aspect of the medial femoral condyle
Osteochondritis Dissecans (OCD)
Capitellum Lesions
