Chronic Sclerosing Osteomyelitis of Garré of the Femur in a 4-Year-Old Girl Caused by Coagulase-Negative Staphylococci: A Case Report.

Background: Chronic sclerosing osteomyelitis of Garré (CSO) is a rare, non-suppurative form of primary chronic osteomyelitis characterized by reactive periosteal bone formation and cortical thickening. It most commonly involves the mandibular bones, whereas long-bone localization is uncommon. Material and Methods: We report a 4-year-old girl who developed progressive right thigh pain and limping six months after receiving intramuscular ampicillin injections. Subsequent evaluation revealed femoral changes consistent with chronic sclerosing osteomyelitis. Surgical decompression and targeted antimicrobial therapy were performed. Results: Microbiological analysis of intraoperative specimens obtained prior to antibiotic therapy yielded Staphylococcus epidermidis (S. epidermidis) and Staphylococcus capitis (S. capitis). After three years of follow-up, the patient exhibited no functional impairment or growth disturbance of the affected limb. Conclusions: Although coagulase-negative staphylococci (CoNS) are commonly regarded as skin commensals, their repeated isolation from deep surgical specimens, together with clinical findings and response to treatment, raises the possibility of their involvement in the disease process in this case.