First case of calcaneal Brodie's abscess caused by Fusobacterium nucleatum in an immunocompetent adult

<h2>Abstract</h2> Subacute calcaneal osteomyelitis is a challenging condition with a high relapse rate. This case report presents the first documented instance of subacute osteomyelitis of the calcaneus caused by <i>Fusobacterium nucleatum</i>, manifesting as post-traumatic heel pain in a 24-year-old male. The patient presented with heel pain following a fall, with no history of penetrating injury or immunosuppression. Imaging (Radiograph/CT/MRI) revealed a growing lytic lesion with surrounding bone marrow edema in the calcaneum. Surgical drainage and debridement were performed, and intraoperative cultures identified <i>Fusobacterium nucleatum</i>. The patient was treated with parenteral tazocin and oral metronidazole, followed by six weeks of oral doxycycline and metronidazole. Inflammatory markers normalized over three weeks, and the patient showed satisfactory recovery with follow-up radiographs and clinical reviews. This case highlights the importance of considering <i>Fusobacterium nucleatum</i> in subacute calcaneal osteomyelitis and demonstrates the effectiveness of combined surgical and antibiotic treatment.