Complex Open Fractures of the Lower Extremity: What is the Optimal Time from Bone Fixation to Flap Coverage?

Area of Science:

• Orthoplastic surgery
• Trauma surgery
• Wound healing

Background:

• Shorter delays to soft tissue coverage for lower extremity open fractures correlate with reduced infection rates.
• Orthoplastic teams need to understand safe flap delay times post-internal fixation (IF), not just post-presentation, due to concurrent critical injuries.
• This study investigated infection rates based on flap coverage delays within 24 hours, 24-72 hours, and over 72 hours after IF.

Purpose of the Study:

• To determine the optimal timing for flap coverage after internal fixation in patients with severe lower extremity fractures.
• To identify predictors of infection following flap coverage in complex fracture cases.
• To evaluate the relationship between the delay of flap coverage and subsequent infection rates.

Main Methods:

• A retrospective cohort study was conducted on 274 adult patients with Gustilo III lower extremity fractures treated at a Level 1 trauma center (2011-2021).
• Patients underwent flap coverage after internal fixation.
• Multivariate logistic regression analyzed infection predictors, including demographics, flap type, fixation method, antibiotics, and timing of coverage relative to presentation and fixation.

Main Results:

• Of 274 patients, 76 (27.7%) developed infections.
• The average time from fixation to flap coverage was 84.9 hours for non-infected patients and 106.6 hours for infected patients (p=0.074).
• Infection rates for flap coverage delays of <24 hours, 24-72 hours, and >72 hours were 23.2%, 25.0%, and 31.5% respectively (p=0.40). Time from fixation to flap coverage was the sole significant predictor of infection (p=0.04).

Conclusions:

• The time interval between internal fixation and flap coverage is a significant predictor of post-operative wound infection.
• While the infection rate for delays over 72 hours did not reach statistical significance in this cohort, larger studies may confirm this trend.
• Soft tissue coverage should ideally be performed within 72 hours of internal fixation to minimize infection risk in lower extremity open fractures.