T&O: Bone Infections

Question 1

Acute osteomyelitis: sources and organisms

Answer 1

Can be local (from surgery) or haematogenous

Organisms: staph aureus (main one), strep, E. coli, pseudomonas, salmonella

Question 2

Acute osteomyelitis: risk factors

Answer 2

vascular disease, trauma, immunosuppression, children (rich blood supply to growth plate)

systemic disease

Question 3

Acute osteomyelitis: signs and symptoms

Answer 3

Pain, tenderness, erythema, warmth, decreased ROM

Effusion in neighbouring joints

Signs of systemic infection/coryzal symptoms

Question 4

Acute osteomyelitis investigations

Answer 4

Raised ESR/CRP/WCC

Positive blood cultures in 60% of pts

X-ray: haziness + decreased bone density, sub-periosteal reaction

MRI: sensitive and specific

Question 5

Acute osteomyelitis management

Answer 5

IV ABX Vanc+cefotaxime (check local trust guidelines!)

may take several weeks

Drain abscess and remove sequestration

Analgesia

Question 6

Septic arthritis: source, differential and organisms

Answer 6

Source: local or haematogenous

Differential: crystal arthropathy, reactive arthritis

Organisms: staph (60%), streps, gonococcus, gram -ve bacilli

Question 7

Septic arthritis: risk factors and symptoms

Answer 7

Risk factors: joint disease (RA), chronic renal failure, immunosupression, prosthetic joints

Symptoms: acutely inflamed, tender, swollen joint, decreased ROM, systemically unwell

Question 8

Septic Arthritis investigations

Answer 8

Joint aspiration for MCS

Raised ESR/CRP, blood cultures

X ray

Question 9

Septic arthritis: Mx and complications

Answer 9

IV ABX

Consider joint washout under GA

Splint joint

Physio after infection resolved

Complications: osteomyelitis, Arthritis, ankylosis (fusion)

Question 10

Avascular necrosis: pathophysiology

Answer 10

Disruption of blood supply either due to interruption of arterial inflow (fracture) or blockage of venous outflow (infiltrative disorders)

Question 11

Avascular necrosis: causes

Answer 11

Fracture/dislocation

Sickle cell disease: clumping of RBCs leads to diminished capillary flow - infarcted areas of bone become infected with unusual organisms such as salmonella

Decompression sickness/Caisson disease/Bends

Gaucher’s disease: rare familial disorder of lipid metabolism - blocks venous outflow

Drug induced: esp corticosteroids

Idiopathic