Exploring the Connection between Flap Type and Infection in Lower Extremity Fractures

Muscle flaps were historically considered superior to fasciocutaneous (FC) flaps for coverage of open fractures and exposed hardware. However, both flap types are now commonly used in modern lower extremity (LE) reconstruction, and it remains unclear whether postoperative infections rates differ. This study compares postoperative infection rates between muscle and FC flaps in free flap reconstruction following open LE fractures.A retrospective review was conducted on patients aged ≥18 years treated from 2011 to 2021 for open LE fractures requiring flap reconstruction after internal fixation. Demographics, injury characteristics, and perioperative factors were collected. The primary outcome was postoperative infection that could not be treated with antibiotics alone and required an unplanned return to the operating room for washout within 9 months of reconstruction. Univariate and multivariate analyses compared outcomes between muscle and FC flaps in free flap reconstruction.Of 164 patients, 86 (52.4%) had muscle flaps and 78 (47.6%) had FC flaps. Muscle flaps were more commonly used in patients with higher injury severity scores and injuries involving the knee/lower leg. The overall postoperative infection rate was 23.2%, with no significant difference between muscle or FC flaps (25.6 vs. 20.5%, <i>p</i> = 0.56). On multivariate analysis, muscle and FC flap types were not predictors postoperative infection. Other outcomes, including reoperation, length of hospital stay postreconstruction, time to ambulation, and secondary amputation rates, were similar between flap types.In reconstruction of open LE fractures, muscle and FC flaps yield comparable infection rates and complication profiles. Therefore, flap selection should be guided by injury characteristics, patient factors, and reconstructive goals.