Acute osteomyelitis and septic arthritis in children

To review the clinical presentation, clinical management and organisms responsible for acute haematogenous osteomyelitis (AHO) and septic arthritis (SA) in the post Haemophilus influenzae type B (Hib) vaccine era and to evaluate current Australian antibiotic guidelines for these conditions.

A retrospective chart review of children less than 16 years of age presenting to The Children's Hospital at Westmead in the period from January 1998 to July 2002 with an ICD discharge code consistent with AHO or SA.

During the 4 1/2-year period 120,511 children were admitted to The Children's Hospital at Westmead. There were 102 cases of AHO and 47 cases of SA during this time. An organism was identified either by blood culture or tissue biopsy in 45% of children with AHO and 38% with SA. Staphylococcus aureus was the most common identifiable causative organism accounting for 76% of isolated organisms in AHO and 39% of isolated organisms in SA. Methicillin-resistant S. aureus (MRSA) was responsible for 9% of AHO and 6% of SA cases. There were no cases due to Haemophilus influenzae or Kingella kingae during the study period. The majority (66%) of children with AHO were managed non-operatively with intravenous and then oral antibiotics. Thirty-five (34%) children had operative treatment to drain pus. In contrast, 74% of the patients with SA had one or more surgical procedures performed to drain pus from involved joints.

Staphylococcus aureus remains the most common organism causing AO and SA; however, community-acquired methicillin-resistant strains are now occurring. Haemophilus influenzae is no longer a common cause of SA. Our study supports the current Australian antibiotic guidelines that recommend flucloxacillin alone as the empiric treatment of choice of both AHO and SA in children fully immunised against Hib. However the possibility of community-acquired MRSA should be considered, particularly in high risk groups such as indigenous Australian children or children from regional areas with a high rate of community-acquired MRSA.