Osteomyelitis

Osteomyelitis is infection of bone. This lesson’s high-yield pathway is acute haematogenous osteomyelitis in children, in which bacteria commonly seed the metaphysis of a long bone. Staphylococcus aureus is the principal target; Kingella kingae is also important in children. The bedside pattern may be subtle: focal bone pain, limp, refusal to use an extremity, or pseudoparalysis may occur with or without fever. The immediate clinical task is to obtain cultures promptly, start appropriate empiric therapy, and use the clinical response, inflammatory-marker trend, and imaging to identify children who need oral step-down, broader treatment, drainage, or debridement. The cefazolin-based 3–4-week pathway described below applies to uncomplicated acute paediatric disease. Chronic infection, vertebral disease, contiguous infection from a diabetic foot or pressure injury, open-fracture infection, and hardware-associated infection require a different risk assessment and often specialist-directed antimicrobial and surgical planning.