BONE AND JOINT INFECTION Flashcards
What do we call infection of the bone?
Osteomyelitis
What is the usual source of infection in osteomyelitis cases?
Haematogenous spread - often secondary to infected wound
Where in the bone does osteomyelitis usually start?
In the metaphysis, where there is relative stasis of blood
Which bones are most often affected by osteomyelitis?
2/3rds of cases occur in femur or tibia
What is the peak age of incidence for osteomyelitis?
Neonatal period
9-11 year children
What is the pathogen most commonly responsible for osteomyelitis?
S. aureus
Other than s. aureus, what pathogens are known to commonly cause osteomyelitis in children?
Group B streptococcus
E. coli - neonates only
Should also consider M. tuberculosis
Which group of patients are more at risk of developing osteomyelitis?
Sickle cell disease
Osteomyelitis caused by what other pathogen are children with sickle cell disease particularly prone to?
Salmonella osteomyelitis
What are the clinical features of osteomyelitis in a child?
Fever
Pain
Limp
Refusal to move affected limb
Exquisite tenderness over affected bone
Red, warm area
What are the investigations that should be done in someone who presents with signs and symptoms consistent with osteomyelitis?
FBC - raised WCC
CRP - raised
ESR - raised
Blood cultures
Bone aspiration for culture and antibiotic sensitivity
Imaging
What imaging should be done for a child who presents with osteomyelitis?
MRI, USS and bone scans are more sensitive in the early phase of illness (24-48 hours)
X-rays tend to be normal for the first 10 days
How do we manage a child with osteomyelitis?
Urgent IV antibiotics until clinical improvement and normalising of acute phase reactants.
Oral antibiotics for several weeks after coming off IV.
Surgical drainage may be indicated if non-adequate response to antibiotics.
What antibiotics should be used in the treatment of osteomyelitis?
Flucloxacillin and sodium fusidate
What antibiotics should be used in the treatment of osteomyelitis in a patient who is allergic to penicillin?
Clindamycin
What antibiotics should be used in the treatment of osteomyelitis where salmonella is suspected as the causative organism?
Ceftriaxone
What are the complications of osteomyelitis?
Chronic osteomyelitis
Septic arthritis
Growth disturbance and limb deformity - especially if infection affects epiphyseal plate)
Which is more common in kids: osteomyelitis or septic arthritis?
Septic arthritis
In what age group is the incidence of septic arthritis highest?
Younger than 3 years old
What is the main source of infection for septic arthritis?
Haematogenous spread
What is the most common site of septic arthritis in infants?
Hip
What is the most common site of septic arthritis in older children?
Knee
What is the pathogen most commonly responsible for septic arthritis?
S. aureus
What are the clinical features of septic arthritis in a child?
Fever
Irritability
Refusal to weight bear
Infants will often hold limb rigid (pseudoparalysis)
Tenderness over joint
Red, hot and swollen
