Complication Rates After Hip or Knee Arthroplasty in Morbidly Obese Patients

Abstract

BACKGROUND: Morbid obesity has been shown to be a risk factor for increased complications after THA and TKA; however, large studies that would determine the effect size are lacking. QUESTIONS/PURPOSES: The purposes of this study were to determine whether morbid obesity increased the risk of: (1) venous thromboembolism (VTE), (2) bleeding, (3) other adverse events, and (4) infections during the early postoperative period (up to 6 to 8 weeks) after THA or TKA? METHODS: Data from the REgulation of Coagulation in ORthopaedic surgery to prevent Deep vein thrombosis and pulmonary embolism (RECORD) clinical trial program of rivaroxaban for prevention of VTE after THA or TKA were analyzed retrospectively. Data for 12,355 patients were reviewed to identify complication rates in morbidly obese patients (BMI≥40 kg/m2) compared with patients with a BMI less than 40 kg/m2. Explorative analyses compared the rates of asymptomatic deep vein thrombosis (DVT), symptomatic DVT, symptomatic pulmonary embolism, bleeding, and other adverse events by BMI group. RESULTS: There were no significant differences in asymptomatic DVT, symptomatic DVT, symptomatic pulmonary embolism, or bleeding, but there were increases in other adverse events (including receipt of blood transfusion, erythema, peripheral edema, diarrhea, gastrointestinal or abdominal pain) and infections (including respiratory tract or lung infections, wound inflammation or infection, and extrasurgical-site infections), in patients with a BMI of 40 kg/m2 or greater compared with patients with a BMI less than 40 kg/m2. CONCLUSIONS: After THA or TKA, morbid obesity is not associated with an increased risk of VTE or bleeding but is associated with increased early postoperative complications, including erythema, peripheral edema, diarrhea and gastrointestinal or abdominal pain, wound inflammation or infection, extrasurgical-site infections, and respiratory tract or lung infections. LEVEL OF EVIDENCE: Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.