A rare case report: MRSA osteomyelitis after CRPP for pediatric distal both-bone forearm fracture.

BACKGROUND: Distal forearm fractures are common pediatric injuries. While Closed Reduction and Percutaneous Pinning (CRPP) is a standard treatment with excellent outcomes, subsequent poliomyelitis is a less commonly reported but serious complication. This case highlights the diagnostic and therapeutic challenges of managing Methicillin-resistant Staphylococcus aureus (MRSA) fracture-related infection (FRI), particularly in the presence of subtle initial signs. CASE PRESENTATION: A 9-year-old male underwent CRPP for a right distal forearm fracture (Fig. 1). Intraoperative radiographs confirmed satisfactory alignment and pin placement. Postoperative Day 1 radiograph confirmed satisfactory alignment (Fig. 2). At five weeks postoperatively, he developed persistent pain, wrist swelling, and skin ulceration after K-wire removal. Laboratory results showed elevated inflammatory markers (C-reactive Protein (CRP): 10 mg/L, Erythrocyte Sedimentation Rate (ESR): 52 mm/h) despite a normal white blood cell count. Magnetic resonance imaging (MRI) revealed bone marrow edema and a subperiosteal abscess in the distal ulna and radius. The patient underwent surgical debridement of the distal ulna and implantation of antibiotic-loaded bone cement. Culture of the intraoperative pus confirmed MRSA. Management included a 3-week in-hospital course of intravenous vancomycin, transitioned to oral linezolid and rifampin, guided by susceptibility testing. A second-stage surgery with iliac crest bone grafting was successfully performed after infection control. At the six-month follow-up, radiographic union was achieved, with full functional recovery of the wrist and no signs of infection recurrence. Long-term physeal monitoring is ongoing. The patient remains under annual surveillance, and follow-up will continue until skeletal maturity to monitor for potential growth disturbance. CONCLUSIONS: This case underscores the importance of suspecting FRI in children with persistent pain despite normal radiographs, highlights the diagnostic value of CRP/ESR and MRI, and demonstrates that a guideline-based, multidisciplinary approach can achieve excellent short-term outcomes. Long-term physeal monitoring is essential. The management strategy emphasizes the role of timely surgical intervention, targeted antibiotic therapy, and staged reconstruction in complex pediatric bone infections.