title: Computer navigation is effective in reducing blood loss but has no effect on transfusion requirement following primary total knee arthroplasty: a meta-analysis.
abstract: OBJECTIVE
  This meta-analysis was designed to evaluate the effects of computer navigation on blood conservation after total knee arthroplasty (TKA) by comparing postoperative blood loss and need for allogenic blood transfusion in patients undergoing computer navigation and conventional primary TKAs.
  
  
  METHODS
  Studies were included in this meta-analysis if they compared change in haemoglobin concentration before and after surgery, postoperative blood loss via drainage or calculated total blood loss, and/or allogenic blood transfusion rate following TKA using computer navigation and conventional methods. For all comparisons, odds ratios and 95 % confidence intervals (CI) were calculated for binary outcomes, while mean difference and 95 % CI were calculated for continuous outcomes.
  
  
  RESULTS
  Twelve studies were included in this meta-analysis. The change in haemoglobin concentration was 0.39 g/dl lower with computer navigation than with conventional TKA (P = 0.006). Blood loss via drainage was 83.1 ml (P = 0.03) lower and calculated blood loss was 185.4 ml (P = 0.002) lower with computer navigation than with conventional TKA. However, the need for blood transfusion was similar for the two approaches (n.s.).
  
  
  CONCLUSIONS
  The primary TKA with computer navigation was effective in reducing haemoglobin loss and blood loss, but had no effect on transfusion requirement, compared with conventional primary TKA. These findings suggest the importance of analysing several blood loss parameters, because each may not always accurately reflect true postsurgical bleeding.
  
  
  METHODS
  Meta-analysis, Level III.
authors.affiliation: Department of Orthopaedic Surgery, College of Medicine, Anam Hospital, Korea University, Seoul, South Korea.
authors.forename: Seung-Beom
authors.initials: SB
authors.lastname: Han
authors.affiliation: Department of Preventive Medicine, College of Medicine, Korea University, Seoul, South Korea.
authors.forename: Hyun-Jung
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Department of Orthopaedic Surgery, College of Medicine, Seoul National University Bundang Hospital, Seoul National University, Seongnam, South Korea.
authors.forename: Tae-Kyun
authors.initials: TK
authors.lastname: Kim
authors.affiliation: Department of Orthopaedic Surgery, College of Medicine, Seoul St. Mary's Hospital, Catholic University, Seoul, South Korea.
authors.forename: Yong
authors.initials: Y
authors.lastname: In
authors.affiliation: Department of Orthopaedic Surgery, Konkuk University Hospital, Konkuk University School of Medicine, Seoul, South Korea.
authors.forename: Kwang-Jun
authors.initials: KJ
authors.lastname: Oh
authors.affiliation: Department of Orthopaedic Surgery, College of Medicine, Seoul St. Mary's Hospital, Catholic University, Seoul, South Korea.
authors.forename: In-Jun
authors.initials: IJ
authors.lastname: Koh
authors.affiliation: Department of Orthopaedic Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Ilwon-ro, Gangnam-gu, Seoul, 135-710, South Korea. eoak22@empal.com.
authors.forename: Dae-Hee
authors.initials: DH
authors.lastname: Lee
mesh_terms: D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D016063:Blood Loss, Surgical / Q000517:prevention & control*; D001803:Blood Transfusion / Q000706:statistics & numerical data*; D004322:Drainage; D006801:Humans; D019106:Postoperative Hemorrhage / Q000517:prevention & control* / Q000628:therapy; D025321:Surgery, Computer-Assisted / Q000379:methods*
keywords: Blood loss; Computer-assisted; Navigation; Total knee arthroplasty; Transfusion