Infection SKEL B Flashcards
Osteomyelitis definition:
Infection of bone and bone marrow
3 categories of Osteomyelitis
Acute - developing w/in 2 weeks of disease onset
Subacute - developing w/in one to several months
Chronic - developing after several months
90% of Suppurative Osteomyelitis is due to ___________ _____________
Staphylococcus Aureus
Typical Non-suppurative Osteomyelitis typically involves what organism?
Mycobacterium tuberculosis
Syphilitic (LUES) congenital/acquired osteomyelitis typically involves what organism?
Treponema pallidum
List 4 principle mechanisms of osseous and articular contamination.
- Hematogenous. - Via bloodstream
- Spread from a contiguous source - cutaneous, sinus and dental infections
- Direct Implantation - penetrating injuries (usually feet)
- Postoperative infection. - contamination of surgical sites
MC age group of Osteomyelitis
2-12 years old
Gender Ratio of Osteomyelitis?
3:1 Male
MC sites of Osteomyelitis?
Large tubular bones: femur, tibia, humerus, and radius most often
Late Stage patients with Osteomyelitis will typically reveal involucrum, cloaca, and sequestra on plain-film radiographs. What do these words mean?
Involucrum - A thick sheath of periosteal new bone around a sequestrum. (Periosteal Rx) “bony Collar” continuation of periosteal response. Will eventually represent the new periosteum.
Cloaca - the draining sinus (the occurrence of a defect that may develop in the involucrum)YR 1375
Sequestra - Segments of necrotic bone separated from living bone by granulation tissue. Chalky, white area representing dead bone
Found in chronic Osteomyelitis, what radiographic sign may be present after 20-30 years with chronic disease, a rare, but significant complication of the draining sinus.
Marjolin’s Ulcer - epidermoid carcinoma occurring at a sinus tract
Brodie’s Abscess, a low-grade infection usually seen in children, may mimic _______________.
Osteoid Osteoma
what percent of skeletal infectious disease with involve the spine?
10%
Definition of Tom Smith Arthritis:
The spread of metaphyseal osteomyelitis to the adjacent joint when the metaphysis is intracapsular.
I.e. proximal/distal femur and humerus
Distal tibia
Septic Arthritis Definition
Infection of joint (synovial tissue, articular surfaces)
Osteitis Definition
Inflammatory condition usually confined to cortex
Suppurative Osteomyelitis definition
Bone marrow infection by (pyogenic) non-tubercular organism
Staph. Aureus
Strep. Pneumoniae
E. Coli
Pseudomonas
The latent (hidden) stage of Suppurative OM lasts how long?
1-10 days
How long and what findings occur radiographically with the early stage of Suppurative OM?
Days 10-21,
Decreased bone density + soft tissue
The middle stage radiographically associated with a patient who has had Suppurative OM for weeks would show __________ + __________________.
Moth-eaten destruction + periosteal reaction
Septic Arthritis is most common in joints in which _______________.
The capsule covers metaphysis
In a pediatric patient with loss of disc space we think _________. Never ___________.
Infection!, never DDD Degenerative disc disease
The most common cause of infection-related death worldwide?
Tuberculosis
King of disease (very prevalent)
Disease of kings (no one spared)
Clinical Features of Non-Suppurative OM?
Respiratory symptoms weight loss Night sweats Vague joint/ back pain Persistently elevated ESR Erythrocyte Sedimentation Rate
TB Septic Arthritis PHEMISTER’S TRIAD:
Juxtarticular osteporosis
Marginal erosions
Slow joint space loss
Radiographic feautures of TB, Non-Suppurative OM:
Similar to OM in the spine but add:
Multiple Levels
Paraspinal cold abscesses with Ca+
