Primary subacute hematogenous osteomyelitis of navicular bone: A rare case report in 7-year-old child

Introduction and importance Navicular bone location of primary subacute hematogenous osteomyelitis uncommon. There are few cases reported in literature. We aim to describe the clinico-radiological features of primary subacute hematogenous osteomyelitis of the navicular bone in a 7-year-old child, to explain our management of this rare disease and demonstrate that medical treatment without surgery is enough. Case presentation A 7-year-old child presented to emergency department. His chief complaint was fever, left limping and foot pain. The positive examination features of were painful palpation of the dorsal side of the foot and a swelling of the homolateral ankle. The erythrocyte sedimentation rate was high. The x-ray revealed a lytic lesion of the left navicular bone. The MRI findings led to the diagnosis of subacute osteomyelitis. Pain relief and normalization of inflammatory markers were obtained after 8 weeks of antibiotic therapy. Complete radiological healing was obtained after 9 months. One year after treatment, the patient was able to practice sports as previously. Clinical discussion Subacute osteomyelitis of the navicular bone in pediatric population is a rare condition. This case shows the importance of early diagnosis thanks to MRI findings and appropriate antibiotic therapy based on the endemic bacteriological profile. Conclusion The navicular bone may develop primary subacute osteomyelitis in immunocompetent child. Early diagnosis is important for prescribing effective conservative treatment.
Highlights • Subacute osteomyelitis of the navicular bone is an etiology of lameness in children. • The penumbra sign on MRI is strongly suggestive of the infectious origin of the bone involvement. • Medical treatment without surgery can lead to a cure. • Antibiotic therapy should be sufficiently prolonged for at least 3 months.