Does the Timing, Type, and Method of Flap Coverage After Open Tibia Fracture Fixation Influence the Rate of Deep Infection?

Objectives: To evaluate whether the timing of flap coverage following definitive fixation influences deep infection and nonunion in patients with Gustilo-Anderson (GA) Type 3B and 3C open tibia fractures, accounting for flap method (local vs. free) and tissue type (muscle vs. fasciocutaneous).

Methods: Retrospective cohort study of patients with GA 3B and 3C tibia fractures treated at a Level I trauma center (2013-2022) with fracture fixation and soft-tissue reconstruction. Primary outcomes were deep surgical site infection and nonunion, assessed by timing of flap coverage (≤ 72 vs. > 72 h), tissue type, and flap method.

Results: Fifty-one patients (52 extremities) met inclusion criteria. Deep infection was significantly higher after free (13/30, 43%) versus local flaps (0/22; p < 0.001). There was a trend toward increased infection rates when coverage occurred >72 h post-fixation (9/30, 30%) versus ≤ 72 h (4/22, 18%; p = 0.33). Among free flaps, coverage ≤ 72 h had fewer infections (4/13, 31%) than coverage > 72 h (9/17, 53%; p = 0.22). Tissue type and timing had no significant effect: muscle ≤ 72 h (4/20, 20%) vs. > 72 h (8/23, 35%; p = 0.28); fasciocutaneous ≤ 72 h (0/2) vs. > 72 h (1/7, 14%; p > 0.99). Nonunion was more common with free flaps (13/30) than local flaps (2/22; p = 0.007). Free flaps placed ≤ 72 h had fewer nonunions (4/13, 31%) than those placed > 72 h (9/17, 53%; p = 0.22).

Conclusions: Free flaps were associated with higher rates of deep infection and nonunion. Although not statistically significant, there was a trend toward increased complications with coverage > 72 h, especially for free and muscle flaps.