title: Imageless navigation versus traditional method in total hip arthroplasty: A meta-analysis.
abstract: OBJECTIVE
  Accuracy of acetabular component orientation is improved with computer navigation in THA. In recent years, imageless navigation has become more commonplace, whereas there still exist different arguments about this technique.
  
  
  METHODS
  We conducted a meta-analysis to assess the accuracy of imageless navigation for acetabular implantation in total hip arthroplasty. The computer based online search strategy covered the major medical databases (Cochrane Library, Medline, Pubmed, and EmbaseI) from January 2004 to December 2014. Data of selected clinical trials were analysed using Revman 5.1 software.
  
  
  RESULTS
  7 clinical trials enrolling 485 patients were included. Mean cup inclination and anteversion were not statistically significantly different between the conventional groups and the imageless computer navigated groups (P = 0.83 and P = 0.89 respectively). Deviation from the desired position of inclination shows no significant differences (P = 0.06), whereas deviation from the desired position of anteversion was smaller in computer navigated group (P<0.0001). Only one study gave useful information about operation time which is significantly increased (MD = 23.00, P = 0.001).
  
  
  CONCLUSIONS
  Current literature generally hold the opinion that navigation is a reliable tool to optimize cup placement, but still there are some different voices about imageless navigation system. This meta-analysis emphasizing more on the accuracy of cup-positioning with imageless navigation reveals that imageless navigation is preferable compared with traditional method.
authors.affiliation: Department of Orthopedics, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, 430000, PR China.
authors.forename: Zhengye
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Department of Radiology Oncology and Medical Oncology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, 430000, PR China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Gao
authors.affiliation: Department of Orthopedics, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, 430000, PR China. Electronic address: guke3559@aliyun.com.
authors.forename: Lin
authors.initials: L
authors.lastname: Cai
mesh_terms: D019644:Arthroplasty, Replacement, Hip / Q000379:methods*; D006801:Humans; D061646:Operative Time; D025321:Surgery, Computer-Assisted / Q000379:methods*
keywords: Computer navigated; Imageless navigation; Meta-analysis; RCTs; Total hip arthroplasty