Long-Term Risk of Prosthetic Joint Infection in Patients With Hypoalbuminemia Following Hip or Knee Arthroplasty.

Background: Arthroplasty literature describes preoperative hypoalbuminemia as a risk factor for perioperative complications. A correlation between low postoperative albumin levels and acute infection-related complications has been studied in cardiothoracic and abdominal surgery. We aim to further characterize postoperative hypoalbuminemia, independent of preoperative albumin level, as a risk factor for long-term complications in arthroplasty, specifically knee and hip periprosthetic joint infections (PJIs). Methods: The TriNetX database was queried for patients undergoing primary or revision hip or knee arthroplasty from January 1, 2000 to January 1, 2024. Cohorts were defined as patients with normal postoperative albumin levels (≥3.5 g/dL) and those with postoperative hypoalbuminemia (<3.5 g/dL) on postoperative days 1-3. These cohorts were propensity matched based on demographics, comorbidities, and preoperative albumin level. PJI rates at 3 months, 1 year, and 5 year were compared between cohorts. Results: Low postoperative albumin level following hip arthroplasty was associated with approximately 2.5 times increased risk of PJI within 3 months, and a 2.3 times increased risk at later time points. In patients who underwent knee arthroplasty, postoperative hypoalbuminemia was associated with a lesser but significant PJI risk of 1.4- to 1.5-fold at all time points. Conclusions: Risk for PJI in patients with low postoperative albumin, independent of preoperative albumin level, is substantial, up to 2.5 times in those undergoing hip arthroplasty. This risk is also elevated for knee arthroplasty patients. This likely represents an acute marker of the surgical "hit," underscoring the importance of better defining the underlying mechanisms and associated biomarkers to improve acute care, complications surveillance, and identify therapeutic interventions.