T/F: Brodie’s abscess formations may be sterile with no mcroorganisms cultured.
True
What is the main way to differentiate infections from tumors on xray?
infections do not respect growth plates or joint spaces
What is the proper treatment for bone infections?
coffee enemas
…jk it’s antibiotics.
Joint effusion, juxtaarticular osteoporosis, erosions, joint space loss, and lytic destruction that CROSSES THE JOINT space…what is this?
septic arthritis
How many mm is the teardrop distance?
> 11mm and >2mm difference from the opposite joint
unilateral sacroilitis
think infection
Where do spinal infections begin in adolescents?
In adults?
in the disc (still vascular);
anterior endplates then disc then soft tissue (paraspinal mass)
Where are spinal infections most common?
lumbars
What joints have a higher incidence of infection in IV drug users?
SI joints
What are some early radiographic features of bone infection?
rapid disc space loss and/or endplate destruction
T/F: Osteomyelitis typically shows up in the first week on plain films.
False;
t/F: Osteomyelitis may show up on bone scintigraphy within hours.
True
What type of imaging gives a direct view of intramedullary disorders and may precede bone scan findings?
MRI
T/F: Osteomyelitis findings on MRI will show increased (white) signal intensity on T1 and decreased on T2.
False; white is right on T1 so pathology findings are dark or decreased on T1, increased on T2
What is the classic finding associated with osteomyelitis in the spine?
disc space loss with endplate destruction
Word association: Nonsuppurative osteomyelitis, Pott’s disease, and mycobacterium
Tuberculosis
What is the most common cause of infection-related death in the world, with 15 million people infected in the US?
Tuberculosis
T/F: Only 1-3% of TB cases involve the skeleton, but this is the most common secondary form of TB
true
TB in the skeleton usually involves weight-bearing joints and multiple levels. What is the most common area for TB in the skeleton?
TL junction
How does TB of the spine look different than osteomyelitis?
multiple level involved and paraspinal cold abscesses with Ca+
Word association: weight loss, fever, chills, night sweats, Gibbous formation and granulomas on chest film in 50%
TB
What is the Phemister’s Triad?
sign of tuberculosis septic arthritis:
Juxtarticular osteoporosis, marginal erosions, and slow joint space loss
What is the term for death of osseous cellular and marrow components of bone with an epiphyseal predispostion, especially of the femur head and humeral head?
Avascular Necrosis
What are some synonyms for avascular necrosis (AVN)?
osteonecrosis, ischemic necrosis, or osteochondrosis
When does epiphyseal necrosis (AVN) become clinically evident?
with articular surface collapse
Surgery, trauma, alcoholism, and corticosteroid use are common etiologies for AVN but what is the most common etiology?
spontaneous/idiopathic
What is the term for AVN in children?
Legg-Perthes disease
The acronym PLASTIC RAGS is used to list the different causes of AVN. What does it stand for?
Pancreatitis/pregnancy Legg-Perthes disease/Lupus Alcoholism/Atherosclerosis Steroids Trauma Idiopathic/Infection Caisson disease/Collagen disease Rheumatoid arthritis/Radiation treatment Amyloid Gaucher disease Sickly cell disease/spontaneous
What is the time frame from initial infarction to healed deformity with AVN?
2-8 years
During the revascularization phase of AVN, new bone is deposited directly onto dead bone, thickening the trabeculation and increasing bone density. What is this termed?
“creeping substitution”
What are some general radiological feature of epiphyseal infarction?
mottled trabecular pattern fragmentation collapse of articular cortex sclerosis subchondral cysts subchondral fracture
When are mottled trabeculation patterns associated with AVN most commonly seen?
during the revascularization and repair phases
“Rim Signs” or “Crescent Signs” are aunt minnie signs associated with AVN. What do these signs indicate?
subchondral fractures separating articular cortex from cancellous bones