Perioperative Blood Loss During Total Hip Arthroplasty Among Patients With Ankylosing Spondylitis.

Intraoperative blood loss is frequently an overarching concern during total hip arthroplasty (THA) for patients who have ankylosing spondylitis with hip involvement. However, the factors that affect blood loss have not been identified. The goal of this study was to investigate these factors among patients with ankylosing spondylitis. Patients in the authors' department who had ankylosing spondylitis and underwent unilateral THA from 2011 to 2016 were studied retrospectively. Demographic characteristics, perioperative laboratory values, intraoperative data, transfusion rate, transfusion volume, and data on hemostatic use were collected and analyzed statistically. Multiple and univariate linear regression analyses were performed. As a result, 44 patients were eligible for inclusion in the study. Mean age was 31.7±10.6 years, and mean disease duration was 9.7±5.8 years. Mean body mass index was 21.30±3.01 kg/m2. Mean volume of blood loss during THA was 1735.19±756.04 mL. Multiple linear regression analysis showed that perioperative blood loss was positively associated with Ankylosing Spondylitis Disease Activity Score (ASDAS), fibrinogen concentration, and surgical time. Further evaluation with univariate linear regression analysis suggested that ASDAS, red blood cell transfusion, and change of hematocrit concentration from preoperatively to postoperatively were correlated with blood loss. Disease activity, allogeneic blood transfusion volume, and change of hematocrit concentration from preoperatively to postoperatively appeared to be positively associated with perioperative blood loss during THA for patients with ankylosing spondylitis. For these patients, disease activity and the potential for allogeneic transfusion should be considered carefully before surgery. [Orthopedics. 2017; 40(5):e904-e910.].