Bone Infection Flashcards
What sex is more likely to be affected by osteomyelitis?
M>F
Give risk factors for acute osteomyelitis?
Open bone fracture/trauma history
Orthopaedic surgery
Immunocompromised
HIV
Sickle cell anaemia
Tuberculosis
DM
Secondary infection
What organisms can cause acute osteomyelitis?
Staph aureus
Group B streptococci
E coli
Strep pyogenes
Haemophilus influenzae
Salmonella species
Mycobacterium tuberculosis
Pseudomonas aeroginosa
What organism is the most common cause of osteomyelitis?
Staph aureus
What organism is associated with acute osteomyelitis in patients with sickle cell disease?
Salmonella species
How does acute osteomyelitis present?
Refusing to move limb/weight bear
Pain
Swelling
Tenderness
Low grade fever
What is the imaging modality of choice in osteomyelitis?
MRI
What investigations are used in acute osteomyelitis diagnosis?
FBC
- Increased WCC
>ESR and CRP
Blood cultures X3, at peak of temperature
Xray or bone scan
Bone marrow aspiration or bone biopsy
What acute osteomyelitis signs are seen on xray?
Normal in the first 10-14 days
Sequestrum/late osteonecrosis
Involucrum/late formation of new bone in response to injury
Regional osteopenia
Focal corticol loss
Periosteal changes
Give complications of acute osteomyelitis
Septicemia, death
Metastatic infection
Pathological fracture
Septic arthritis
Altered bone growth
Chronic osteomyelitis
Give the complication of sub-acute osteomyelitis
Brodie’s abscess, well defined cavity in cancellous bone
How is acute osteomyelitis managed?
Supportive
- Fluids
- Analgesia
- Rest and splintage
Antibiotics
- 4-6 weeks
- Flucloxacillin plus fusidic acid, clindamycin if penicllin allergic
- Start IV and switch to oral when stable
Extensive surgical cleaning
What is the most common location of osteomyelitis in children?
Metaphysis
What is the most common location of osteomyelitis in adults?
Epiphysis
What causes chronic osteomyelitis?
May follow acute osteomyelitis, but is much rarer in children
De novo/new onset
- Following operation
- Following open surgery
- Immunosuppressed, diabetics, elderly, drug abusers etc
Repeated breakdown of healed wounds
What organisms cause chronic osteomyelitis?
Often mixed infection
Usually same organism each flare up
Staph Aureus
E Coli
Strep Pyogenes
Proteus
How does chronic osteomyelitis present?
Chronically discharging sinus and flare-ups
Ongoing/metastatic infection causing abscesses
Pathological fracture
Growth disturbance and deformities
Squamous cell carcinoma
How is chronic osteomyelitis managed?
Antibiotics
- At least 12 weeks, usually 3-6 months
- Treatment is usually delayed until culture and sensitivity results are obtained
Surgical debridement
What is septic arthritis?
Bacteria causing rapid irreversible cartilage destruction resulting in monoarthritis, presenting as a hot, swollen and tender joint
Give risk factors for septic arthritis
IVDU
Age >80
Comorbidities
- DM, RA
Endocarditis due to septic showers
Surgery/dental work
Immunocompromised
What organisms cause septic arthritis?
Staphylococcus aureus
Haemophilus influenzae, children
Streptococcus pyogenes
Neisseria Gonorrhoea, young sexually active adults
Staph epidermis, prosthesis
E-coli, IVDU
Pseudomonas, IVDU
Salmonella, sickle cell disease
What organism is the most common cause of septic arthritis?
Staphylococcus aureus
How does septic arthritis present?
Tender swollen joint
Reduced range of movement
Effusion
Erythema
Systemic features such as fever and lethargy
What investigations are used in septic arthritis diagnosis?
Joint aspiration prior to antibiotic therapy
- Sent for gram stain, culture and crystal examination
- Purulent
- In ED if native joint or in surgery if replacement joint
