Preoperative Platelet and International Normalized Ratio Thresholds and Their Impact on Complications Following Revision Total Joint Arthroplasty.

Background: Traditional thresholds of platelet counts ≥50,000/μL and international normalized ratio (INR) < 1.5 may not adequately capture the risks of mild coagulopathy. This study evaluated complication rates across varying preoperative platelet and INR values in patients undergoing revision total joint arthroplasty. Methods: Patients undergoing revision total knee or hip arthroplasties were retrospectively identified from a health care database. Patients were stratified by preoperative platelet counts (50,000 to 100,000/μL, 100,000 to 150,000/μL, >150,000/μL) and INR (<1.0, 1.1 to 1.5, 1.6 to 2.0, >2.0) recorded within 30 days of surgery. Following 1:1 propensity score matching to adjust for confounders, evaluated outcomes included transfusions, bleeding, thromboembolic events, wound complications, periprosthetic joint infection (PJI), reoperation, and mortality up to 2 years. Results: Platelet counts of 50,000 to 100,000/μL were associated with increased transfusions, greater 90-day bleeding, and higher 2-year PJI and mortality. Counts of 100,000 to 150,000/μL were similarly linked to higher transfusions, PJI, and mortality. An INR of 1.1 to 1.5 correlated with increased 90-day transfusions, wound complications, and thromboembolic events, alongside higher 2-year PJI, reoperation, and mortality. INR levels >1.5 were consistently associated with elevated 90-day thromboembolic events and increased 2-year PJI, with levels of 1.6 to 2.0 also linked to higher mortality. Conclusions: The findings from this study indicate that preoperative platelet counts below 150,000/μL and INR values above 1.0 were associated with higher rates of complications following revision total joint arthroplasty. These results suggest stricter optimization of hematologic parameters preoperatively may reduce complications.