Atopic dermatitis is a novel demographic risk factor for surgical site infection after anterior cruciate ligament reconstruction

Purpose Although various risk factors for surgical site infection after anterior cruciate ligament reconstruction (ACLR) have been reported, the number of studies with large sample sizes on this topic is limited. The aim of the present study was to clarify the risk factors for early surgical site infection after ACLR in a large cohort using a national database in Japan. Methods The data of patients who underwent ACLR from 2010 to 2015 were obtained from the Diagnosis Procedure Combination database, which covers approximately half of all hospital admissions in Japan. The outcome measures were the prevalences of surgical site infection and deep surgical site infection after ACLR during hospitalization. The association between the occurrence of surgical site infection and patients' demographic data, including sex, age, body mass index (BMI), smoking status, preoperative steroid use, and comorbidities such as diabetes, hepatic dysfunction, renal dysfunction, and atopic dermatitis, were examined using a multivariable logistic regression model. Results Among 30,536 patients who underwent ACLR, 288 patients with surgical site infection (0.94%) and 86 with deep surgical site infection (0.28%) were identified. The univariate analysis showed that higher prevalences of surgical site infection and deep surgical site infection were associated with male sex, a higher BMI, atopic dermatitis, and preoperative steroid use. Patients with diabetes or hepatic dysfunction had a significantly higher prevalence of surgical site infection. The multivariable analysis showed that surgical site infection was significantly associated with male sex vs. female sex; odds ratio (OR), 2.90; 95% confidence interval (CI), 2.17-3.89, age of <= 19 vs. 20-29 years; OR, 1.56; 95% CI 1.13-2.15, BMI of >= 30.0 vs. 18.5-22.9 kg/m(2); OR, 1.72; 95% CI 1.16-2.54, diabetes (OR, 2.70; 95% CI 1.28-5.71), atopic dermatitis (OR, 7.19; 95% CI 2.94-17.57), and preoperative steroid use (OR, 6.18; 95% CI 2.32-16.52). Conclusion Atopic dermatitis, preoperative steroid use, young age (<= 19 years), obesity (BMI of >= 30.0 kg/m(2)), male sex, and diabetes were independent demographic risk factors for surgical site infection after ACLR. The present study will be useful when surgeons evaluate the risk of SSI after ACLR in terms of demographic aspects.