25 - Bone and Joint Infection Flashcards
Epidemiology of Septic Arthritis
8 per 100,000 in UK
45% > 65y/o
very young and very old
90% monoarticular
What is septic arthritis
Common destructive arthropathy - infection of the joint
Presentation of septic arthritis
Fever higher than 39 degrees (1/3rd of cases)
Limitation of joint movement
Swelling
Ways for bacteria to accumulate in the joint
Blood supply (haematogenous)
Penetrating trauma - open fractures
Infection in the local soft tissue
Adjacent osteomyolitis
Common organisms in septic arthritis
Staphylococcus aureus
common bacteria is neonate septic arthritis
Haemophilus influenza
What destroys the joint in septic arthritis
the cytokines produced from the immune reaction
Predisposing factors to SA
Pre existing arthritis
Previous damage to the joint
Untreated systemic infection
Trauma
Most commonly affected joints in SA
Knee
also hip, ankle, elbow
not usually fingers, wrist, shoulder
Lab findings for SA
Elevated ESR
Neutrophillia
Synovial fluid of SA
Turbid/purulent - lumpy or cloudy due to dead neutrophils
Gram stain positive in 1/3rd
Radiology of early stages of SA
Soft tissue swelling
Joint capsule distention
Radiology of later stages of SA
Erosion of articular surface
Soft tissue swelling
Osteopenia (loss in joint space)
Treatment for septic arthritis
Drainage
Antibiotics IV 3-4 weeks
start with broad spectrum
What is reactive/reiter’s arthritis
Post infectious arthritis
preceded by enteric or genitourinary infection (STI)
What is potts disease
TB into the vertebrae
Destroy the vertebrae
Pushes onto the spinal cord
Where does osteomyelitis usually occur in the bone
Usually at the metaphysis side of the epiphyseal growth plate
Predisposing factors of osteomyelitis
Impairment of immune surveillance - malnutrition, extremes of age
Impairment of local vascular supply - diabetes, SCD
Clinical features of osteomyelitis
Decreased limb movement Adjacent joint effusion High fever Local non-specific pain Elevated ESR Brodies abcess
What can chronic osteomyelitis result in
Local bone loss and persistent drainage through sinus
Management of osteomyelitis
Surgical debridement to remove dead bone
Reconstruct bone
Antibiotics for 4-6 weeks (2 wks IV)
What is the sequestrum
The dead bone which is attacked by bacteria
What is the Involucrum
New bone shell
Which antibiotic is recommended to give in osteomyelitis
Vancomycin
