Abstract
The aim of this study was to determine the incidence, annual trend, and perioperative outcomes and identify risk factors of early-onset ( ≤ 90 d) deep surgical site infection (SSI) following primary total hip arthroplasty (THA) for osteoarthritis. We performed a retrospective study using prospectively collected patient-level data from January 2013 to March 2020. The diagnosis of deep SSI was based on the published Centre for Disease Control/National Healthcare Safety Network (CDC/NHSN) definition. The Mann-Kendall trend test was used to detect monotonic trends. Secondary outcomes were 90 d mortality and 90 d readmission. A total of 22 685 patients underwent primary THA for osteoarthritis. A total of 46 patients had a confirmed deep SSI within 90 d of surgery representing a cumulative incidence of 0.2 %. The annual infection rate decreased over the 7-year study period ( p = 0.026 ). Risk analysis was performed on 15 466 patients. Risk factors associated with early-onset deep SSI included a BMI > 30 kg m -2 (odds ratio (OR) 3.42 [95 % CI 1.75-7.20]; p < 0.001 ), chronic renal disease (OR, 3.52 [95 % CI 1.17-8.59]; p = 0.011 ), and cardiac illness (OR, 2.47 [1.30-4.69]; p = 0.005 ), as classified by the Canadian Institute for Health Information. Early-onset deep SSI was not associated with 90 d mortality ( p = 0.167 ) but was associated with an increased chance of 90 d readmission ( p < 0.001 ). This study establishes a reliable baseline infection rate for early-onset deep SSI after THA for osteoarthritis through the use of a robust methodological process. Several risk factors for early-onset deep SSI are potentially modifiable, and therefore targeted preoperative interventions of patients with these risk factors is encouraged.