CLINICAL AND DIAGNOSTIC FEATURES OF OSTEOMYELITIS OCCURRING IN THE FIRST 3 MONTHS OF LIFE

We report a retrospective study of 94 infants, ages <4 months, who und erwent investigation for possible osteomyelitis during a 9-year period . Of the 30 babies with proven osteomyelitis (radiographic changes or positive bone cultures or positive blood cultures plus a compatible cl inical picture), 17 were preterm artificially ventilated babies and 4 were full term infants receiving intensive care. An etiologic organism was isolated from 28: methicillin-susceptible Staphylococcus aureus, 16; methicillin-resistant S. aureus (MRSA), 7; Escherichia coli, 3; an d group B Streptococcus, 2. MRSA occurred exclusively in the preterm g roup. Osteomyelitis was multifocal in 40% and associated with septic a rthritis in 47%. The long bones were frequently affected (80%) whereas the flat bones were often sites of clinically silent disease. Twenty- five (83.3%) of the 30 babies with proven osteomyelitis had focal clin ical signs or evidence of disseminated staphylococcal disease. Only 10 were febrile. Four of 27 babies investigated because of positive bloo d cultures for S. aureus but no focal signs had osteomyelitis, as did only 1 of 27 babies with suspected sepsis but no focal signs. The sens itivity of Tc-99m bone scanning was 84%, specificity 89%, positive pre dictive value 79% and negative predictive value 92%. The addition of g allium scanning (in 39 of the 94 infants) improved the respective figu res to 90, 97, 93 and 95% and was useful in interpreting equivocal bon e scans.