title: Benefit of intraoperative navigation on glenoid component positioning during total shoulder arthroplasty.
abstract: BACKGROUND
  The objective of this study was to review and synthesize the current best evidence for the use of intraoperative navigation in the implantation of glenoid components in total shoulder prostheses.
  
  
  METHODS
  We conducted a systematic, online search using PubMed, EMBASE, CCTR, and CINAHL using "Arthroplasty, Replacement"(Mesh) AND (shoulder) AND (navi* OR computer). Data on study design and quality as well as accuracy of positioning and complications were extracted independently and in duplicate. After assessment of study heterogeneity, DerSimonian-Laird random effect models were used to pool data from the individual studies.
  
  
  RESULTS
  The systematic search revealed 359 manuscripts in total. After exclusion of duplicates and irrelevant publications, 6 groups of 247 shoulders from 5 studies were included. The pooled weighted mean difference for deviation from neutral version was -6.4° (95 %CI -7.9 to -5.3) in favor of navigation, which is consistent with a statistically significant difference (p < 0.01). In the navigation group, 2 superior glenoid screws were reported as perforating compared to 5 screws (1 inferior, 4 superior) in the control group. There was no difference in tilt at a WMD of 2.7 (95 %CI -1.4 to 6.8, p = 0.192).
  
  
  CONCLUSIONS
  Navigation allows for significantly more accurate glenoid version, but the clinical meaningfulness of the absolute improvement over standard techniques is questionable. However, navigation is a valuable teaching tool that might prove very beneficial not for the patient at hand, but for those treated by the operating surgeon in the future.
  
  
  METHODS
  Level II-meta-analysis of non-homogenous controlled trials.
authors.affiliation: Department of Orthopedic Surgery, Medical University of Graz, Auenbruggerplatz 5, 8036, Graz, Austria, patricksadoghi@gmx.at.
authors.forename: Patrick
authors.initials: P
authors.lastname: Sadoghi
authors.forename: Julia
authors.initials: J
authors.lastname: Vavken
authors.forename: Andreas
authors.initials: A
authors.lastname: Leithner
authors.forename: Patrick
authors.initials: P
authors.lastname: Vavken
mesh_terms: D019643:Arthroplasty, Replacement / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D007432:Intraoperative Period; D007595:Joint Prosthesis; D012540:Scapula / Q000601:surgery*; D012785:Shoulder Joint / Q000601:surgery*; D013238:Stereotaxic Techniques; D025321:Surgery, Computer-Assisted