Sub-emergency versus emergency or delayed free flap coverage for Gustilo III upper limb fractures: With reduced infection, enhanced limb salvage, and improved functional recovery.

BACKGROUND

Gustilo type III open fractures of the upper extremity present severe soft‑tissue and bony injuries. Free flap reconstruction is standard, but the optimal timing remains debated. This study aimed to assess the association between timing of coverage and postoperative infection rates.

METHODS

In this observational cohort study, 85 patients with upper limb Gustilo III fractures (2018-2024) were allocated to three groups based on clinical decision: emergency (same anesthetic, n = 25), sub‑emergency (within 72 h, n = 26), or delayed (>72 h, n = 34). Demographics, perioperative data, and complications were analyzed. Multivariable logistic regression was performed but limited by low event numbers.

RESULTS

Baseline characteristics were comparable except for higher Injury Severity Score (ISS) in the delayed group (p = 0.001). Infection rates were 4.0% (1/25) in emergency, 3.8% (1/26) in sub‑emergency, and 29.4% (10/34) in delayed group (p = 0.001). Osteomyelitis, flap necrosis, and bone defects occurred almost exclusively in the delayed group. Multivariable analysis (13 total infections) did not identify timing as an independent predictor (p = 0.831); higher ISS, longer operative time, and extended hospital stay showed trends but were not statistically significant. Functional recovery (QuickDASH, SF‑12 PCS) was superior in both early groups. Patient satisfaction was highest in the sub‑emergency group.

CONCLUSIONS

In this observational study, free flap coverage beyond 72 h was associated with higher unadjusted infection rates; however, this finding cannot be interpreted causally due to severe confounding-by-indication, as the delayed cohort sustained significantly higher baseline trauma severity (ISS). Emergency and sub-emergency (<72 h) coverage demonstrated comparable favorable outcomes, suggesting that the sub-emergency window represents a safe, logistically advantageous alternative LEVEL OF EVIDENCE: III; Therapeutic.