Staged non-bridging circular external fixation with sequential osteoporosis therapy for MRSA-infected distal radius non-union: a case report.

BACKGROUND: Infected distal radius non-union in elderly patients with severe osteoporosis is particularly challenging because infection eradication, stable fixation, and preservation of wrist function must be achieved simultaneously. Conventional internal fixation in an infected osteoporotic field carries a high risk of recurrent infection and fixation failure, whereas bridging external fixation may result in prolonged immobilization and functional deterioration. We report a case of methicillin-resistant Staphylococcus aureus (MRSA)-infected distal radius non-union treated with staged non-bridging circular external fixation combined with sequential osteoporosis therapy. CASE PRESENTATION: An 85-year-old woman with severe osteoporosis developed MRSA-infected distal radius non-union after failed plate fixation. A staged treatment strategy was employed. In the first stage, non-bridging circular external fixation was applied, followed by implant removal, radical debridement, and vancomycin-loaded hydroxyapatite implantation, together with systemic antibiotic therapy. Immediate wrist mobilization and low-intensity pulsed ultrasound therapy were initiated. After infection control, second-stage autologous cancellous bone grafting was performed. Weekly teriparatide therapy had been initiated preoperatively and was continued for 18 months, followed by annual intravenous administration of zoledronic acid. Radiographic union was achieved 3 months after bone grafting. At final follow-up (5 years), the Disabilities of the Arm, Shoulder, and Hand (DASH) score was 10.7, with preserved wrist motion and full functional independence. No recurrence of infection or refracture was observed. CONCLUSIONS: Staged non-bridging circular external fixation combined with sequential osteoporosis therapy may represent a potential salvage approach for infected distal radius non-union in severely osteoporotic elderly patients. This approach enables infection control, stable fixation, and early mobilization while preserving wrist function. However, as this is a single case treated with multiple simultaneous interventions, the findings should be interpreted cautiously and considered hypothesis-generating.