Atypical Presentation of Post-sternotomy Sternal Osteomyelitis: The Role of Multimodal Imaging in Community Hospital Diagnosis

Sternal osteomyelitis is an uncommon but serious complication of median sternotomy and may present with atypical manifestations that delay diagnosis.It is considered a form of deep sternal wound infection (DSWI) that extends beyond the deep fascia and may involve the sternal bone and adjacent mediastinal tissues.We report a case of delayed post-sternotomy sternal osteomyelitis presenting four months after coronary artery bypass grafting.A 70-year-old woman with obesity and poorly controlled diabetes mellitus presented with atypical chest pain and a localized mid-sternal rash first noticed less than one week prior.Acute coronary syndrome was ruled out on admission.Laboratory evaluation was significant for markedly elevated inflammatory markers (CRP 134.1 mg/L, ESR 101 mm/hr).Contrast-enhanced computed tomography of the chest and bone scintigraphy revealed supportive findings consistent with active sternal infection.The diagnosis of sternal osteomyelitis was made based on a compatible clinical presentation following prior sternotomy, markedly elevated inflammatory markers, and concordant multimodal imaging evidence of sternal involvement.Given the absence of hemodynamic instability, mediastinal extension, sternal instability, or purulent discharge, the patient was managed medically with intravenous, followed by oral, antimicrobial therapy.Her clinical status and laboratory findings improved, and surgical debridement was not required.This case highlights an atypical presentation of delayed post-sternotomy sternal osteomyelitis and the diagnostic value of multimodal imaging in community hospital settings when tissue confirmation is deferred.It further supports conservative medical management with close monitoring in selected patients without features of mediastinitis or structural compromise.