Bone and joint infection Flashcards
What is the likely diagnosis: acute, severely painful, red hot swollen joint. What is the likely causative organism?
Septic arthritis
Staph aureus
What is the “best guess” antibiotic treatment for septic arthritis?
Flucloxacillin
Why might a patient with rheumatoid arthritis be more likely to get septic arthritis?
Immunosuppressed, usually older patients, abnormal joint structure/physiology
If more than one joint is affected by septic arthritis, what possibility should be considered?
Septic emboli from endocarditis
What is osteomyelitis?
Infection of bone
What is osteomyelitis usually caused by?
Inoculation by penetrating injury or recent surgery
When does acute osteomyelitis occur in the absence of surgery?
Children or immunocompromised adults
Why are children more prone to osteomyelitis?
Metaphyses of long bones contain abundant tortuous vessels which can accumulate bacteria
What is a Brody abscess?
Walled-off abscess seen in children resulting from a subacute insidious osteomyelitis
What is the treatment of acute osteomyelitis? If the infection does not resolve what procedure should be performed?
Best guess flucloxacillin. Bone biopsy for culture and sensitivities
What may develop within the bone structure in chronic osteomyelitis?
Sequestrum- area of dead/dying bone
Involucrum- new bone surrounding the necrosed area
How is chronic osteomyelitis managed?
May need tp perform surgery as well as antibiotics- debride any sequestra, infected bone, and may need to stabilise bone with external/internal fixation
What other surgical strategies may be used in chronic osteomyelitis?
Local antibiotic delivery systems, bone grafting, plastic surgery to ensure skin and soft tissue coverage of bone
How can arthroplasties become infected?
Usually perioperatively- commensals, or wound infection
Which organisms cause a) early and b) late arthroplasty infections?
a) Usually s.aureus b) staph epidermidis (coagulase -ve staph)
