Comparison study of patient demographics and risk factors for infections following primary total hip arthroplasty for femoral neck fractures.

INTRODUCTION While studies have shown favorable outcomes in the treatment of femoral neck fractures with the utilization of total hip arthroplasty (THA), adverse events, such as infections, can still occur. Therefore, the aims of this study were to 1) compare baseline demographics and 2) identify risk factors associated with developing either surgical site infections (SSIs) or peri-prosthetic joint infections (PJIs). MATERIALS AND METHODS A retrospective analysis of patients who underwent primary THA for femoral neck fractures were queried from the Medicare database. The inclusion criteria consisted of patients developing SSIs within 90 days or PJIs within 3 years following the index procedure. The query yielded 2502 patients who developed infections in the form of either SSIs (n = 987) or PJIs (n = 1515) out of 57,191 patients treated for femoral neck fractures with primary THA. Primary endpoints were to compare baseline demographic profiles and determine risk factors associated with developing infections. Multivariate binomial logistic regression analyses were performed to determine the odds (OR) of developing infections. A p value less than 0.001 was considered to be statistically significant. RESULTS Patients who developed either infections were found to be significantly different when compared to patients who did not develop infections. SSI (10 vs. 8, p < 0.0001) and PJI (9 vs. 5, p < 0.0001) patients both had significantly higher mean Elixhauser Comorbidity Index (ECI) scores compared to their counterparts. The regression model found the greatest risks for developing SSIs included hypertension (OR 1.63, p = 0.001), pathologic weight loss (OR 1.58, p < 0.0001), and iron deficiency anemia (IDA) (OR 1.48, p < 0.0001), whereas IDA (OR 2.14, p < 0.0001), pathologic weight loss (OR 1.75, p < 0.0001), and rheumatoid arthritis (OR 1.57, p < 0.0001) increased the odds for PJIs. CONCLUSION This study can be utilized by orthopedic surgeons and other healthcare professionals to adequately educate these patients of the complications which may occur following their surgery.