Chronic Thrombocytopenia and In-Hospital Outcomes After Primary Total Hip and Knee Arthroplasty

There is a lack of data on the influence of chronic thrombocytopenia (cTCP) on clinical outcomes following primary total hip arthroplasty (THA) and total knee arthroplasty (TKA). Limited studies mainly focused on postoperative heparin-induced TCP from single centers with small sample sizes. This study aims to describe the characteristics, trend, and outcomes of cTCP in patients undergoing THA and TKA from a nationally reprehensive perspective.We identified THA and TKA patients with and without cTCP from the 2005 to 2015 Nationwide Inpatient Sample. Annual percent changes were calculated to reflect cTCP trends. Multivariable regression and propensity score analyses were conducted to investigate the association of cTCP and mortality, preoperative complications, cost as well as length of stay.In total, 578,278 and 1,237,331 patients underwent primary THA and TKA, respectively. Proportion of cTCP annually increased by 6.95% in THA and 6.66% in TKA. Patients with cTCP were associated with higher risk of medical (odds ratio [OR] 2.00, 95% confidence interval [CI] 1.89-2.11) and surgical complications (OR 2.72, 95% CI 2.55-2.90) in THA, and higher risk of mortality (OR 1.68, 95% CI 1.22-2.31), medical (OR 1.94, 95% CI 1.85-2.03) and surgical complications (OR 2.55, 95% CI 2.38-2.73) in TKA. Additionally, higher cost and longer length of stay were observed in patients with cTCP for both surgical procedures.Patients with cTCP had higher risk of mortality for TKA, more perioperative complications for both TKA and THA. Further studies are warranted to improve the preoperative management and to prevent worse outcomes associated with cTCP.