title: Changes in coagulation functions and hemorheological parameters may predict hematoma formation after total knee arthroplasty.
abstract: BACKGROUND
  Hematoma formation around the knee is commonly seen after total knee arthroplasty (TKA) and may cause patient discomfort and worry regarding the success of the surgery. This study aimed to evaluate the coagulation functions and hemorheological parameters in patients undergoing TKA and investigate their associations with hematoma formation.
  
  
  METHODS
  This study prospectively included 146 patients treated for knee osteoarthritis by unilateral TKA between August 2013 and August 2014. Apixaban was administered twice during the 12-24-h period after surgery. Blood coagulation functions were evaluated according to activated partial thromboplastin time (APTT), prothrombin time (PT), thrombin time, and fibrinogen preoperatively and on postoperative days 1, 3, 7, and 14. Hemorheological parameters were also measured. Patients were divided into a hematoma group and a non-hematoma group for comparison.
  
  
  RESULTS
  On postoperative day 1, the hematoma group showed significantly prolonged APTT and PT and significantly decreased hematocrit relative to baseline values (P < 0.05). The whole blood high shear rate, whole blood low shear rate, plasma viscosity, and hematocrit did not differ significantly between the two groups at baseline or from postoperative days 1-14 in (P > 0.05).
  
  
  CONCLUSIONS
  Prolonged APTT and PT on the first day after TKA as well as decreased hematocrit may indicate an increased risk of hematoma formation. Postoperative use of apixaban may promote the formation of ecchymoses but is not a major contributing factor.
authors.affiliation: The First Affiliated Hospital, Jinan University, Guangzhou, 510632, China.|Institute of Orthopaedic Disease Research, Jinan University, Guangzhou, 510632, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Liu
authors.affiliation: The First Affiliated Hospital, Jinan University, Guangzhou, 510632, China.|Institute of Orthopaedic Disease Research, Jinan University, Guangzhou, 510632, China.
authors.forename: Simin
authors.initials: S
authors.lastname: Luo
authors.affiliation: Macau Medical Science & Technology Research Association, Macau, China.
authors.forename: Cheanglek
authors.initials: C
authors.lastname: Hang
authors.affiliation: The First Affiliated Hospital, Jinan University, Guangzhou, 510632, China. zhzgg@vip.163.com.|Institute of Orthopaedic Disease Research, Jinan University, Guangzhou, 510632, China. zhzgg@vip.163.com.
authors.forename: Zhengang
authors.initials: Z
authors.lastname: Zha
authors.affiliation: The First Affiliated Hospital, Jinan University, Guangzhou, 510632, China.|Institute of Orthopaedic Disease Research, Jinan University, Guangzhou, 510632, China.
authors.forename: Jieruo
authors.initials: J
authors.lastname: Li
authors.affiliation: The First Affiliated Hospital, Jinan University, Guangzhou, 510632, China.|Institute of Orthopaedic Disease Research, Jinan University, Guangzhou, 510632, China.
authors.forename: Wenrui
authors.initials: W
authors.lastname: Wu
authors.affiliation: The First Affiliated Hospital, Jinan University, Guangzhou, 510632, China.|Institute of Orthopaedic Disease Research, Jinan University, Guangzhou, 510632, China.
authors.forename: Dabiao
authors.initials: D
authors.lastname: Hou
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects*; D001777:Blood Coagulation / Q000502:physiology*; D004334:Drug Administration Schedule; D065427:Factor Xa Inhibitors / Q000008:administration & dosage / Q000009:adverse effects; D005260:Female; D006400:Hematocrit; D006406:Hematoma / Q000097:blood / Q000209:etiology*; D018056:Hemorheology / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000097:blood / Q000601:surgery; D010314:Partial Thromboplastin Time; D019106:Postoperative Hemorrhage / Q000097:blood / Q000209:etiology*; D011184:Postoperative Period; D011446:Prospective Studies; D011517:Prothrombin Time; D011720:Pyrazoles / Q000008:administration & dosage / Q000009:adverse effects; D011728:Pyridones / Q000008:administration & dosage / Q000009:adverse effects; D012307:Risk Factors
chemical_list: D065427:Factor Xa Inhibitors; D011720:Pyrazoles; D011728:Pyridones; C522181:apixaban
keywords: Activated partial thromboplastin time; Apixaban; Hematoma; Prothrombin time; Total knee arthroplasty