Date of Award

January 2023

Document Type


Degree Name

Master of Public Health (MPH)


School of Public Health

First Advisor

Windy Tanner


Background: In the past decades, there has been an increase in the proportion of orthopedic surgical site infections (SSIs) caused by gram-negative bacilli in various healthcare settings. SSI prevention guidelines suggest that gentamicin can be added to prophylactic antibiotic treatment to target gram-negative bacilli. However, the effectiveness of this strategy remains to be confirmed in orthopedic surgery.

Methods: A retrospective cohort study was conducted to investigate the association between antibiotic prophylaxis with adjunctive gentamicin and SSI rates in orthopedic surgeries. 5,571 patients who underwent hip, knee, spine, and hip fracture surgeries between January 2019 and July 2021 at Yale-New Haven Hospital (YNHH) were included. Stratified analysis by surgical procedure was conducted to determine the association between SSI rate and receipt of gentamicin or antibiotic compliance, while adjusting for the American Society of Anesthesiologists (ASA) score.

Results: There was a statistically significant association between the development of an SSI and receipt of prophylactic gentamicin among the hip fracture surgery group (p = 0.006). Additionally, there was a statistically significant association between the development of an SSI and antibiotic compliance among the hip (p = 0.026) and hip fracture (p = 0.040) surgery groups.

Conclusion: Prophylactic antibiotic treatment with adjunctive gentamicin may help lower SSI rates for patients undergoing hip fracture surgery. Further studies, especially robust randomized controlled trials, are necessary to confirm the benefit of adjunctive gentamicin for orthopedic surgery.

Key words: surgical site infection, antibiotic prophylaxis, orthopedic surgery, gram-negative bacilli, gentamicin


This thesis is restricted to Yale network users only. It will be made publicly available on 05/10/2024