What Are the Risk Factors for Infection in Hemiarthroplasties and Total Hip Arthroplasties?

Background Late infection is the second most frequent early complication after total hip arthroplasty (THA) and the most frequent after hemiarthroplasty. Known risk factors for infection after THA include posttraumatic osteoarthritis, previous surgery, chronic liver disease, corticoid therapy, and excessive surgical time. However, risk factors for hemiarthroplasty are not clearly established. Questions/purposes We therefore determined the preoperative and intraoperative risk factors for late infection (more than 3 months after surgery) in patients with hemiarthroplasties and THAs. Methods We retrospectively compared 47 patients with a hip arthroplasty (23 hemiarthroplasties, 24 total hip arthroplasties) and late infection with 200 randomly-selected patients with primary arthroplasty (100 hemiarthroplasties, 100 total hip arthroplasties) during the same time period of time without any infection during followup. Potential risk factors were identified from medical records. Minimum followup was 12 months (mean, 27 months; range, 12-112 months) for the study group and 18 months (mean, 84 months; range, 18-144 months) for the control group. Results The following factors were more frequent in late infected hemiarthroplasties: female gender; previous surgery; obesity (body mass index greater than 30 kg/m(2)); glucocorticoid and immunosuppressant treatments; prolonged surgical time; inadequate antibiotic prophylaxis; prolonged wound drainage; hematoma; dislocation; and cutaneous, urinary, and/or abdominal infections. The following were more frequent in infected total hip arthroplasties: posttraumatic osteoarthritis; previous surgery; glucocorticoids; chronic liver disease; alcohol and intravenous drug abuse; prolonged surgical time; prolonged wound drainage; dislocation; subsequent surgery; and cutaneous, urinary, respiratory and abdominal infections. Diabetes did not appear to be a risk factor. Conclusions Our data suggest there are specific risk factors for infection in hemiarthroplasties. The major risk factors for late infection in hip arthroplasty must be recognized so they can be minimized or controlled if not possible to employ prophylactic measures.