When microsurgery is not an option: staged delayed reverse sural artery flap with ischaemic preconditioning for limb salvage in an elderly patient with chronic post-traumatic osteomyelitis-a case report.

Lower extremity reconstruction in elderly patients with post-traumatic osteomyelitis presents a formidable challenge. We report a 70-year-old female with hypertension, dyslipidaemia, and bilateral knee osteoarthritis who sustained a Gustilo-Anderson type IIIB open right ankle fracture with exposed calcaneus following a fall. The course was complicated by chronic osteomyelitis, managed with partial talectomy and total calcanectomy, antibiotic-impregnated cement spacer placement, cement exchange and prolonged culture-directed intravenous antibiotics. Following infection eradication, definitive hindfoot fusion using a structural femoral head allograft fixed with a retrograde tibiotalocalcaneal arthrodesis nail and compression screws was performed. However, a persistent soft-tissue defect with exposed bone precluded primary closure. Given her age, comorbidities and compromised local vascularity, free tissue transfer was deemed high-risk. Therefore, a 2-stage delayed reverse sural artery flap (RSAF) was selected. The first stage involved flap elevation with ischaemic preconditioning over 2 weeks via stepwise incremental incisional delay, followed by definitive transposition and inset. The donor site was managed with an ovine tendon collagen (OTC) matrix and split-thickness skin grafts (STSGs), supported by intermittent negative-pressure wound therapy (NPWT). At 6-months of follow-up, the flap remained viable and had fully survived, and the patient achieved partial weight-bearing ambulation. This case illustrates the decision-making framework for complex lower limb salvage, highlighting a staged reconstructive strategy integrating the delay phenomenon and adjunctive wound technologies to achieve durable limb salvage when microsurgical reconstruction is contraindicated.