Final - Bone Infection Flashcards
4 different types of osteomyelitis
Suppurative
Non-suppurative
Syphilitic
Mycotic
High risk groups of suppurative osteomyelitis
IV drug users Babies Alcoholics Drug Addicts Diabetic
M/C bacteria to cause osteomyelitis?
Staph. Aureus
4 pathways of osteomyelitis infection
Hematogenous
Contiguous (ST to bone)
Direct implantation
Post Op (combo of direct implantation and hematogenous)
Difference in presentation between young and old patients with osteomyelitis
Young: fever, malaise, signs of bacterial infection, pain and swelling at site of infection, loss of limb function, ^ ESR and WBC
Adults: more insidious onset, chronic, fever, malaise, edema, erythema, pain
M/C age group for osteomyelitis?
2-12
Bone development and epiphyseal blood supply
Infant: no vascular barrier at growth plate until 8 months
Child: Physis acts as barrier to vasculature
Adult: Physis ossified and is no longer a barrier vasculature (can lead to septic arthritis because infection can spread to epiphysis)
Pathophysiology of osteomyelitis
Bacteria get into medullary tissue
What causes lytic destruction in osteomyelitis?
Immune system as it tries to kill the bacteria
What is a sequestrum? Involucum? Cloaca?
Sequestrum: dead, necrotic bone tissue
Involucum: new bony collar formation
Cloaca: Drainage sinus formed in bone d/t infx
Complications of osteomyelitis?
Can become chronic Metastatic infection Angular bone deformation (occurs when one part of the physis prematurely ossifies) Pathological fracture Bacteremia, septicemia ST infection and persistent sinuses
Radiologic features of osteomyelitis? Acute vs chronic?
Can be hard to distinguish between osteosarcoma/Ewing’s sarcoma
Signs of osteomyelitis: throughout bone, lamellated periosteal response, sequestrum and involucum (if present)
Chronic has much more sclerosis and will have sequestrum, involucrum, and possibly cloaca
Osteomyelitis in the spine, child vs adult
With child (>20yo) usually starts in disc, in adult starts in anterior vertebral end plate
Pertinent Hx that may indicate spinal infection? PE fx?
Recent trauma, infection, surgery, insidious onset
Warmth/rubor over vertebra, can’t recreate CC pain
Radiographic findings of osteomyelitis of the spine of kids
Abrupt change in disc space
Tx and prognosis of osteomyelitis
The earlier the Dx and Tx the better the prognosis
Surgical drainage and debridement with PROLONGED antibiotic therapy
What is Brodie’s Abscess? Sx?
Localized osteomyelitis
Local pain that is worse at night and relieved by aspirin (DDx OO)
Brodie’s Abscess radiographic findings
Oval lytic lesion with some sclerosis around border, usually in the metaphysis of long bones
T or F: septic arthritis is m/c polyarticular
False AF
Monoarticular
M/C age group for septic arthritis?
<30 yo
Sx of septic arthritis?
One joint that is warm, has limited ROM and is painful. Systemic signs of infection.
How do you diagnose septic arthritis?
With joint aspiration to identify presence of pathogen
T or F: Septic arthritis progresses very rapidly
True AF
Clinical picture of septic arthritis? (3 parts)
- Fever, malaise,
- Painful swelling in one joint (usually)
- Signs of inflammation
What are the two most common sites of septic arthritis?
Knee and hip
ST finding in septic arthritis?
Joint distension
Fat pad displacement
What is a late sequela of septic arthritis?
Osseous or fibrous ankylosis
If patient has acute symptoms and signs of DJD, whats at the top of your DDx list?
Infection, not just DJD
M/C location where nonsuppurative osteomyelitis spreads from?
Lungs
M/C location for nonsup osteomyelitis?
Thoracic and lumbar
T or F: nonsup osteomyelitis is most common in 25 year olds
False
Most common in people who have immunodeficiency (children, elderly, AIDS, alcoholic, drug abuser, serious illness)
Requires “massive” exposure
M/C cause of nonsup osteomyelitis?
TB
Si/sx of skeletal TB
Insidious onset
Few systemic signs
Mild pain
Appendicular
What is Pott’s disease? M/C location? Earliest radiographic sign? How does it affect ST?
Tubercular spondylitis
25-60% of skeletal TB
Lower Thx upper Lx
Disc space loss
Paravertebral soft tissue mass (often calcification)
Radiographic findings for Tubercular Arthritis
Phemister’s traid
- Progressive joint space narrowing
- Juxtaarticular osteopenia/porosis
- Peripheral erosive defects
Fibrous ankylosis at end stage (osseous is rare)
Latent radiographic period for osteomyelitis of the extremity is what? For spine?
10 days
3 weeks
The earliest radiographic changes in bone and joint infection are first seen where?
ST (elevation of fat planes and blurring of fat muscle interface)
