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 - Zhun Shen Tan; Adzim Poh Yuen Wen; Farzana Ansarutheen; Mohd Yazid Bajuri (Frontiers in Surgery, 2026)