Abstract
Background
Acetabular cup malpositioning during total hip arthroplasty (THA) is known to lead to impingement, instability, wear-induced osteolysis, and increased rates of revision surgery. The purpose of this study was to independently evaluate the accuracy of acetabular cup orientation using a novel mechanical navigation device.
Methods
Postoperative acetabular cup orientation was reviewed in 47 primary THAs using the HipSextant mechanical navigation device. Angles were measured with a validated two-dimensional/three-dimensional matching application. An outlier was defined as +/− 10 degrees outside of the preoperative plan for inclination and anteversion.
Results
Of the 47 THAs, 47 (100%) met our inclination target, 46 (98%) met our anteversion target, and 46 (98%) simultaneously met both targets. There were no outliers for inclination and one outlier (−12.7°) for anteversion (Figure 1). The absolute errors for both inclination and anteversion were significantly less than 10° (p<0.001). There were no intraoperative complications related to the use of this mechanical navigation system.
Conclusions
The HipSextant reliably navigates acetabular cup inclination and anteversion according to a preoperative plan that is individualized for each patient. This should decrease the risk of postoperative complications related to acetabular component malposition during THA. Further research is warranted to assess the clinical impact of reducing outliers using this device.
