Accuracy of navigation-assisted acetabular component positioning studied by computed tomography measurements: methods and results

J Arthroplasty. 2007 Sep;22(6):812-7. doi: 10.1016/j.arth.2006.10.001.


The postoperative position of the acetabular component is key for the outcome of total hip arthroplasty. Various aids have been developed to support the surgeon during implant placement. In a prospective study involving 4 centers, the computer-recorded cup alignment of 37 hip systems at the end of navigation-assisted surgery was compared with the cup angles measured on postoperative computerized tomograms. This comparison showed an average difference of 3.5 degrees (SD, 4.4 degrees ) for inclination and 6.5 degrees (SD, 7.3 degrees ) for anteversion angles. The differences in inclination correlated with the thickness of the soft tissue overlying the anterior superior iliac spine (r = 0.44; P = .007), whereas the differences in anteversion showed a correlation with the thickness of the soft tissue overlying the pubic tubercles (r = 0.52; P = .001). In centers experienced in the use of navigational tools, deviations were smaller than in units with little experience in their use.

Publication types

  • Comparative Study

MeSH terms

  • Acetabulum
  • Aged
  • Arthroplasty, Replacement, Hip / methods*
  • Female
  • Humans
  • Male
  • Prospective Studies
  • Surgery, Computer-Assisted / methods*
  • Tomography, X-Ray Computed