Beyond a Single Clock: Integrating Injury-to-Flap and Fixation-to-Flap Timing in Severe Open Lower-Limb Trauma

Severe open lower-limb fractures requiring flap reconstruction demand coordinated skeletal stabilization and durable soft-tissue coverage.Injury-to-flap timing remains central to care, and current British guidance recommends definitive coverage within 72 hours, with definitive internal fixation accompanied by definitive coverage.Observational evidence increasingly examines a second interval, from definitive fixation to flap reconstruction, but its incremental value and optimal threshold remain uncertain.This narrative review integrates historical studies, contemporary comparative cohorts, systematic reviews, and guidelines, supplemented by targeted literature verification during revision.Several studies associate shorter injury-to-flap or fixation-to-flap intervals with fewer infections.Other cohorts report nonsignificant timing differences or favorable outcomes after selected staged procedures.These findings address different populations, timing origins, and outcomes; they neither establish equivalent safety of delay nor justify relaxing established standards.Confounding by injury severity, physiological instability, wound preparation, and access to specialist care remains substantial.Negative-pressure wound therapy and local antimicrobial strategies are adjuncts, with no demonstrated capacity to neutralize the consequences of delayed coverage.Both intervals should be recorded within a coordinated orthoplastic pathway.Early coverage remains the goal, while clinically necessary deviations require explicit documentation and prompt reassessment.Fixation-to-flap time may identify additional opportunities for improving coordination, but it is not a validated replacement deadline or an unadjusted institutional performance measure.Prospective studies should capture treatment intent, reasons for delay, granular injury severity, consensus-defined fracturerelated infection, and long-term functional outcomes.