Deep infection after acetabular fracture surgery is a serious complication, ranging between 1.2% and 2.5% and has been a challenge for patients and surgeons. It increases length of hospital stay by three to four times due to the need of extra surgeries for debridement, impairs future patient's mobility, and increases the overall costs of care. Aim: We aim to identify pre- and intra-operative risk factors associated with deep infections in surgically treated acetabular fractures.

Methods: In a single-center retrospective case-control study, 447 consecutive patients who underwent open reduction and internal fixation of acetabular fractures were included in the study. Diagnosis of surgical site infections required a combination of clinical signs and positive tissue culture or histological signs of tissue infection according to Lipsky et al (2010) and Fleischer et al (2009). To evaluate risk factors from SSI we performed uni- and multivariate analysis by multiple logistic regression.

Results: Among 447 patients studied, 23 (5.1%) presented diagnosis of postoperative infection. 349 (78.1%) were male with a mean age of 33.3 years old. Posterior wall fractures accounted for 119 cases (26.6%) followed by 102 (22.8%) double column fractures and 57 (12.8%) T fractures. Factors associated with a significantly risk of infection were patient-related: older age and alcoholism (OR = 5.15, 95% CI = 1.06 to 21.98; p=0.036); trauma-related: fractures of the lower limb (odds ratio [OR] = 2.7, 95% confidence interval [CI] = 1.8 to 6.78; p=0.017), comminution (OR = 3.6, 95% CI = 1.19 to 8.09; p=0.009), pelvic ring injuries (OR = 2.89, 95% CI = 1.07 to 7.63; p=0.037); and surgical-related: peri- operative complications (OR = 5.12, 95% CI = 1.85 to 13.8; p=0.001), and dislocation (OR = 0.21, 95% CI = 0.03 to 0.96; p=0.023). Duration of surgery longer than 300 min (p=0.002), and type of surgical approach (p<0.001) were also associated with infection.

Conclusion: Deep infections after acetabular fracture surgery were mainly associated with prolonged duration of surgery and the interrelation with the complexity of the fracture such as double column fractures, combined surgical approach, comminution and intra operative complications. Pelvic ring injuries, lower limb fractures, mean age, no dislocations at the time of accident and alcoholism is others associations.