Osteomyelitis in a child Flashcards
Define osteomyelitis.
Infection of the metaphysis of long bones. Most commonly occurs in the distal femur and proximal tibia.
How common is osteomyelitis?
More common in men
Incidence is 2% per year
More common in adults due to diabetes related disease
What are the causes of osteomyelitis?
Haematogenous spread of infection - direct inoculation into bone or from contiguous focus of infecion
E.g. can be caused by skin infection leading to bactraemia or from more severe cases like bacterial endocarditis
What is the most common microorganism causing osteomyelitis?
S aureus (in all age groups)
Other:
GBS an E coli (infants), GAS, HiB (children), Pseudomonas (foot puncture wounds), Streptococcus pneumoniae, Kingella kingae(<4yrs)
Intravascular devices: S aureus or candida
IV drug use: S aureus or Pseudomonas aeruginosa
Sickle cell: S aureus or Samonella
A 5-year-old boy fell off his bicycle 2 weeks ago, has stopped walking, and complains of non-specific leg pain. His mother reports that he apparently has had flu, with fever and chills. Diagnosis?
Osteomyelitis
What is the typical presentation of acute osteomyelitis?
<1 week history of:
- limp or reluctance to weight bear
- fever
- bone pain
- local redness
- tenderness
- warmth
- swelling
- reduced range of movement
What is the typical presentation of chronic osteomyelitis?
- vague, non-specific pain
- low grade fever of 1-3 months duration
- lethargy and malaise
- persistent drainage from a wound and/or sinus tract
What should you always suspect in osteomyelitis?
- Malignancy
- Sepsis
- Trauma
Also: TB, and Salmonella infection in sickle cell disease
What do investigations show in osteomyelitis?
- FBC - WCC may be raised
- ESR and CRP - raised or normal in chronic disease
- Blood culture (or bone biopsy) prior to starting antibiotics- positive
- Plain x-ray - initially normal with soft tissue swelling
- CT or MRI - may show subperiosteal pus and purulent debris in the bone
- Bone scans can also be done
Others:
- Mantoux test or CXR if TB suspected
- Echo to check for vegetations
- US may show periosteal elevation at presentation
What are the risk factors for osteomyelitis?
- URTI
- Varicella infection
- Hib unvaccinated
- HIV infection
- Recent surgery
- Distant or local infection
- Sickle cell disease
- Rheumatoid arthritis
- CKD
- Immunocompromise
What is the management of osteomyelitis?
- ‘Could this be sepsis?’ –> sepsis protocol, starting IV antibiotics within 1 hour
-
IV antibiotics - several weeks to prevent bone necrosis, chronic infection with a discharging sinus, limb deformity and amyloidosis. Oral once ESR back to normal.
- +/- Aspiration/surgical decompression - if immunodeficient or presentation is unusual
- +/- Surgical darinage if no rapid response to antibiotics
- Rest affected limb in splint until it can be mobilised
What are the complications of osteomyelitis?
- Where the joint capsule is inserted distal to the epiphyseal plate, as in the hip, osteomyelitis may spread to cause septic arthritis
Long term:
- Growth disturbance from premature physeal closure
- Joint stiffness
- Infection recurrence
- Amputation
What is the prognosis of osteomyelitis?
90% will have infection free limbs at 2 years
What is seen on x-rays in acute osteomyelitis?
X-rays are initially normal, other than showing soft tissue swelling;
it takes 7–10 days for subperiosteal new bone formation and localized bone rarefaction to become visible.
Summarise osteomyelitis.
What is shown?
Sacroileitis - widening and irregularity of the right sacroiliac joint, particularly inferiorly consistent with a unilateral sacroileitis
