Research article

Childhood osteomyelitis-incidence and differentiation from other acute onset musculoskeletal features in a population-based study

Øystein Rolandsen Riise^1,2 , Eva Kirkhus³ , Kai Samson Handeland² , Berit Flatø² , Tor Reiseter⁴ , Milada Cvancarova⁵ , Britt Nakstad^6,7 and Karl-Olaf Wathne^1,8

¹Department of Paediatrics, Ullevål University Hospital, Oslo, Norway

²Department of Rheumatology, Rikshospitalet Medical Centre, Oslo, Norway

³Department of Radiology, Rikshospitalet Medical Centre, Oslo, Norway

⁴Department of Radiology, Ullevål University Hospital, Oslo, Norway

⁵Department of Biostatistics, Rikshospitalet Medical Centre, Oslo, Norway

⁶Department of Paediatrics, Akershus University Hospital, Nordbyhagen, Norway

⁷University of Oslo, Akershus Faculty Division, Nordbyhagen, Norway

⁸Ministry of Health and Care Services, Oslo, Norway

author email corresponding author email

BMC Pediatrics 2008, 8:45doi:10.1186/1471-2431-8-45

Published:	20 October 2008

Abstract

Background

Osteomyelitis can be difficult to diagnose and there has previously not been a prospective approach to identify all children in a defined geographic area. The aim of this study was to assess the annual incidence of osteomyelitis in children, describe the patient and disease characteristics in those with acute (< 14 days disease duration) and subacute osteomyelitis (≥ 14 days disease duration), and differentiate osteomyelitis patients from those with other acute onset musculoskeletal features.

Methods

In a population-based Norwegian study physicians were asked to refer all children with suspected osteomyelitis. Children with osteomyelitis received follow-up at six weeks, six months and thereafter as long as clinically needed.

Results

The total annual incidence rate of osteomyelitis was 13 per 100 000 (acute osteomyelitis 8 and subacute osteomyelitis 5 per 100 000). The incidence was higher in patients under the age of 3 than in older children (OR 2.9, 95%: CI 2.3–3.7). The incidence of non-vertebral osteomyelitis was higher than the incidence of vertebral osteomyelitis (10 vs. 3 per 100 000; p = .002). Vertebral osteomyelitis was more frequent in girls than in boys (OR 7.0, 95%: CI 3.3–14.7). ESR ≥ 40 mm/hr had the highest positive predictive laboratory value to identify osteomyelitis patients at 26% and MRI had a positive predictive value of 85%. Long-bone infection was found in 16 (43%) patients. ESR, CRP, white blood cell count, neutrophils and platelet count were higher for patients with acute osteomyelitis than for patients with subacute osteomyelitis. Subacute findings on MRI and doctor's delay were more common in subacute osteomyelitis than in acute osteomyelitis patients. Blood culture was positive in 26% of the acute osteomyelitis patients and was negative in all the subacute osteomyelitis patients.

Conclusion

The annual incidence of osteomyelitis in Norway remains high. ESR values and MRI scan may help to identify osteomyelitis patients and differentiate acute and subacute osteomyelitis.