25 - Bone and Joint Infection

Question 1

Epidemiology of Septic Arthritis

Answer 1

8 per 100,000 in UK
45% > 65y/o
very young and very old
90% monoarticular

Question 2

What is septic arthritis

Answer 2

Common destructive arthropathy - infection of the joint

Question 3

Presentation of septic arthritis

Answer 3

Fever higher than 39 degrees (1/3rd of cases)
Limitation of joint movement
Swelling

Question 4

Ways for bacteria to accumulate in the joint

Answer 4

Blood supply (haematogenous)
Penetrating trauma - open fractures
Infection in the local soft tissue
Adjacent osteomyolitis

Question 5

Common organisms in septic arthritis

Answer 5

Staphylococcus aureus

Question 6

common bacteria is neonate septic arthritis

Answer 6

Haemophilus influenza

Question 7

What destroys the joint in septic arthritis

Answer 7

the cytokines produced from the immune reaction

Question 8

Predisposing factors to SA

Answer 8

Pre existing arthritis
Previous damage to the joint
Untreated systemic infection
Trauma

Question 9

Most commonly affected joints in SA

Answer 9

Knee
also hip, ankle, elbow
not usually fingers, wrist, shoulder

Question 10

Lab findings for SA

Answer 10

Elevated ESR

Neutrophillia

Question 11

Synovial fluid of SA

Answer 11

Turbid/purulent - lumpy or cloudy due to dead neutrophils

Gram stain positive in 1/3rd

Question 12

Radiology of early stages of SA

Answer 12

Soft tissue swelling

Joint capsule distention

Question 13

Radiology of later stages of SA

Answer 13

Erosion of articular surface
Soft tissue swelling
Osteopenia (loss in joint space)

Question 14

Treatment for septic arthritis

Answer 14

Drainage
Antibiotics IV 3-4 weeks
start with broad spectrum

Question 15

What is reactive/reiter’s arthritis

Answer 15

Post infectious arthritis

preceded by enteric or genitourinary infection (STI)

Question 16

What is potts disease

Answer 16

TB into the vertebrae
Destroy the vertebrae
Pushes onto the spinal cord

Question 17

Where does osteomyelitis usually occur in the bone

Answer 17

Usually at the metaphysis side of the epiphyseal growth plate

Question 18

Predisposing factors of osteomyelitis

Answer 18

Impairment of immune surveillance - malnutrition, extremes of age
Impairment of local vascular supply - diabetes, SCD

Question 19

Clinical features of osteomyelitis

Answer 19

Decreased limb movement
Adjacent joint effusion
High fever
Local non-specific pain 
Elevated ESR
Brodies abcess

Question 20

What can chronic osteomyelitis result in

Answer 20

Local bone loss and persistent drainage through sinus

Question 21

Management of osteomyelitis

Answer 21

Surgical debridement to remove dead bone
Reconstruct bone
Antibiotics for 4-6 weeks (2 wks IV)

Question 22

What is the sequestrum

Answer 22

The dead bone which is attacked by bacteria

Question 23

What is the Involucrum

Answer 23

New bone shell

Question 24

Which antibiotic is recommended to give in osteomyelitis

Answer 24

Vancomycin