Can the CRP-to-albumin ratio predict infection chronicity in patients undergoing DAIR?

Periprosthetic joint infection (PJI) is a serious complication of joint replacement, with limited consensus on optimal treatment, especially in early infections. Debridement, antibiotics, and implant retention (DAIR) is often used, but determining the true duration of symptoms and infection chronicity can be challenging. CRP levels rise in both early and chronic infections, while albumin levels decline more gradually due to increased vascular permeability in chronic cases. The CRP-to-albumin ratio may serve as a useful marker of infection chronicity, potentially aiding in treatment decisions between DAIR and more aggressive options used for chronic infections. A retrospective longitudinal study was performed on 82 patients, involving 91 DAIR procedures, with analysis of hospital admission CRP and albumin levels alongside patient-reported symptom onset. The study assessed the correlation between these variables and 1-year clinical outcomes following the DAIR procedure. In addition, CRP-to-albumin ratios were analyzed in a separate group of patients with chronic infections undergoing resection arthroplasty to identify potential similarities between these treatment groups. Reoperation for infection was used as the primary clinical outcome. Forty-nine DAIR procedures were performed in patients with acute infections (0–28 days of symptoms), and 24 DAIR procedures were performed in patients with chronic infections (≥ 29 days of symptoms). An additional 18 procedures in patients with symptoms lasting more than 3 months who underwent resection arthroplasty were included for comparison. The median (IQR) CRP-to-albumin ratio was 2.5 in the acute group (CRP 8.2 mg/L, albumin 3.2 g/dL), 1.0 in the chronic group (CRP 3.8 mg/L, albumin 3.8 g/dL), and 7.2 in the resection group (CRP 28 mg/L, albumin 3.8 g/dL). Reoperation due to infection occurred in 38.8% of the acute group, 70.8% of the chronic group, and 55.6% of the resection group. The use of CRP-to-albumin ratio to predict acute versus chronic infection of total joint arthroplasty does not appear to provide any substantial insights for the surgeon providing care. Additional studies are needed to help provide direction in patient management of these difficult complications. C-reactive protein albumin ratio; debridement and implant retention; periprosthetic joint infection; infection chronicity; predictive marker