Bone flap osteomyelitis following craniotomy in children: A 20-year audit

Bone flap osteomyelitis (BFO) in the paediatric population following craniotomy is rare but is a cause of significant morbidity. We studied the incidence, microbiological profile and surgical outcomes of children who developed BFO.

A retrospective review of medical records of patients < 18 years of age who underwent supratentorial craniotomy in a single neurosurgical unit between January 2004 and December 2023, for non-traumatic and non-infectious indications, was performed.

Of the 519 children studied, nine (1.7%) developed BFO. These nine patients had a median age of 8 years (range, 2-17 years) with the following primary diagnoses - craniopharyngioma (n = 3), moyamoya disease (n = 3), craniosynostosis (n = 2) and ganglioglioma (n = 1). All underwent repeat surgery to either remove the bone flap (n = 7) or debride the osteomyelitic bone (n = 2) and were also administered 6 weeks of antibiotic therapy based on culture reports. The median interval between initial craniotomy and onset of symptom of BFO was 4 months (IQR, 4-6 months) while the median interval between symptom onset and removal of infected bone was 4 months (IQR, 2-9 months). The most common organism isolated was Staphylococcus aureus (n = 4). Histopathological examination of the bone flap in three (33.3%) among the nine patients revealed necrotizing granulomatous inflammation suggestive of tuberculous osteomyelitis, and these patients additionally received anti-tuberculous therapy. At median follow-up of 14 months (IQR, 8-49 months), none of the patients had recurrence of symptoms.

BFO can occur in up to 2% of children following supratentorial craniotomy. Aggressive debridement of the bone flap and removal of osteomyelitic bone combined with appropriate antibiotic therapy yields good long-term outcomes. It is important to consider Mycobacterium tuberculosis as a possible aetiology of BFO, particularly in regions endemic for tuberculosis.