Risk Factors for Infection in Severe Open Tibial Shaft Fractures

Saturday, October 21, 2023

11:43 AM – 11:49 AM PST

Location: 4B

Presenting Author / Corresponding Author(s)

Daniel Johnson, MD

Orthopaedic Trauma Fellow
Baltimore, Maryland, United States

Disclosure(s): No financial relationships to disclose

Co-Author(s)

LR

Lisa Reider, PhD

Johns Hopkins University
Johns Hopkins Bloomberg School of Public Health
William T. Obremskey, MD, MPH, FIOTA (he/him/his)

Director Orthopedic Trauma Fellowship and Research
Vanderbilt University Medical Center
Vanderbilt Ortho Inst
Nashville, Tennessee, United States
Joshua L. Gary, MD

Chief of Orthopaedic Trauma Service
Keck School of Medicine of the University of Southern California
Los Angeles, California, United States
Stephen M. Quinnan, MD

Director of Orthopaedic Trauma and Amputee Reconstruction
Paley Orthopedic & Spine Institute
West Palm Beach, Florida, United States
PT

Paul Tornetta, III, MD, PhD, FIOTA

Professor and Chairman
Boston University Medical Center
Chestnut Hill, Massachusetts, United States
Heather A. Vallier, MD, FIOTA

Case Western Reserve University
Metrohealth Med Ctr
Cleveland, Ohio, United States
EC

Eben Carroll, MD
RO

Robert V. O'Toole, MD

Professor, Orthopaedic Surgery
University of Maryland School of Medicine, R Adams Cowley Shock Trauma Center
Baltimore, Maryland, United States
Nathan N. O'Hara, PhD

Assistant Professor
University of Maryland School of Medicine, R Adams Cowley Shock Trauma Center
Baltimore, Maryland, United States

Group Author(s)

GM

Group METRC

Purpose: The rate of infection in Gustilo-Anderson Type III tibial shaft fractures ranges from 20%s to 50%. Considering the significant morbidity associated with infection in this injury, our study sought to identify risk factors for infection in patients with severe Type IIIA and Type IIIB (requiring soft-tissue flap if limb was left at anatomic length and rotation) tibial shaft fractures. By better understanding factors associated with infection, we hope to identify those who may most benefit from additional preventative or therapeutic measures.

Methods: This is a secondary analysis of the FIXIT trial, a multicenter, randomized controlled trial of severe Type IIIA or IIIB open tibial shaft fractures treated with either internal fixation or ring external fixation. The primary outcome of this secondary study was deep surgical site infection, defined as an infection necessitating surgical debridement within 1 year of the index surgery. An observational cohort of patients that declined randomization was also included in this study. We considered 14 baseline demographic and injury characteristics as potential risk factors. These factors were identified to be studied based on existing literature on orthopaedic trauma-related infection. The multivariate logistic regression model used forward stepwise elimination to select a final set of risk factors. The model was internally validated and the estimates were optimism-corrected using repeated 10-fold cross-validation.

Results: The study cohort for this secondary analysis included 430 patients. Deep surgical site infection requiring reoperation occurred in 108 patients (25%). Our final model identified 4 risk factors for infection and included: age >40 years (odds ratio [OR] 2.00; 95% confidence interval [CI] 1.27-3.13), Gustilo-Anderson Type IIIB (OR 1.80; 95% CI 1.09-2.96), embedded wound contamination (OR 1.69; 95% CI 1.05-2.72), and wound length (OR 1.02 per cm; 95% CI 1.00–1.05).

Conclusion: Based on this secondary analysis of high-quality prospective trial data, surgeons can now counsel patients over 40 years in age as well as those with Type IIIB fractures, longer wound lengths, or embedded wound contamination that they are at markedly higher risk of infection. This may influence treatment decisions and better prepare patients for poor outcomes. Additionally, these risk factors now allow us to begin to better direct future research on how to mitigate the risk in this patient population.

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