Infection - Osteomyelitis Flashcards
What is responsible for around 90% of all bone and joint infections?
Staphylococcus
What are the 4 major pathways of spread of suppurative Osteomyelitis?
Hematogenous
Spread from contiguous source of infection
Direct implantation
Postoperative infection (iatrogenic)
What is the most common source of Osteomyelitis and is involved with UTIs and Respiratory infections?
Hematogenous Spread
What age and gender is most susceptible to suppurative osteomyelitis?
2-12 year old males
What type of bones does suppurative osteomyelitis affect?
large tubular bones
What makes the radiologic and pathologic features of osteomyelitis differ in the infant, child, and adult?
blood supply of growth centers
What does periosteal and subperiosteal area results in?
necrosis of cortex
What do Cortical and medullary infarcts result in?
Sequestrum
What is a significant radiographic feature of infection of the periosteum due to infection and pus in the bone causing new bone formation?
involucrum
What is a defect in the involucrum known as?
Cloaca
What is a cloaca commonly associated with?
Chronic Osteomyelitis
What is a malignant degeneration of a chronic wound or scar that is commonly seen in squamous cell carcinoma?
Marjolin Ulcer
What imaging should you order when you suspect infection?
MRI with and without Gadollinum contrast
What percentage of infections involve extremities? Spine?
Extremities: 90%
Spine: 10%
If infection affects the spine, what part of the spine is most commonly affected?
Lumbar Spine
What age is mostly predisposed to spinal infection?
<20 year olds
What does Adult Spondylitis infection most commonly affect in the spine?
anterior vertebral endplate
What part of the spine will you see widening of retropharyngeal and retrotracheal spaces?
Cervical spine
What part of the spine will you see displacement of paraspinal lines?
thoracic spine
What part of the spine will you see paravertebral or psoas abscesses?
Lumbar spine
What is a localized aborted form of suppurative osteomyelitis that is associated with nocturnal limb pain that is relieved by aspirin?
Brodie’s Abscess
Who does Brodie’s abscesses most commonly affect?
male children
Where in the body does Brodie’s abscess most commonly appear at?
Distal and proximal tibia
What bacteria is most commonly associated with Brodie’s abscess?
Staphylococcus aureus
What bacteria is most commonly associated with Chronic Osteomyelitis?
Staphylococcus aureus
In regards to TB, infection of the musculoskeletal system is commonly caused by what?
hematogenous spread of primary pulmonary focus
What is a common characteristic symptom of TB?
Pott’s Paraplegia: sudden onset of lower limb paraplegia
Pott’s Disease
What age does non-suppurative osteomyelitis of TB affect?
<5yo
What is the key characteristic with Pott’s disease?
erosion of anterior vertebral body endplate
How does TB and Pott’s disease spread in the spine?
Batson’s plexus
What part of the spine does Pott’s disease in regards to TB most commonly seen? What specific level?
lower thoracic and upper lumbar spine
MC: L1
What type of deformity can Pott’s disease lead to in children?
Gibbus Deformity
What part of the body does Tubercular arthritis most commonly affect?
hip and knee
Where does Tubercular arthritis begin and spread to?
Metaphysis to adjacent joint
What type of radiographic lesion is associated with Tubercular arthritis?
Moth-eaten lesion
What is the end-stage of Pott’s disease?
fibrous ankylosis of joint
What is another name for Pott’s Disease?
Tubercular spondylitis
Does Pott’s disease usually affect unilateral or bilateral SI joints?
Unilateral
What is a key radiographic feature of Tuberculous Dactylitis?
spina ventosa
