A comparison between imageless navigated and manual freehand technique acetabular cup placement in total hip arthroplasty.

The purpose of this study was to compare acetabular component positioning using an imageless system to a matched control group using conventional techniques. Thirty procedures were performed using navigation. A multislice computed tomographic scan was used to assess cup position. There was no significant difference between mean inclination (P = .11) and anteversion (P = .24) but a statistical significant difference for mean deviation from the desired position for inclination (P = .003) and anteversion (P = .007). There was a significant difference in the percentages of correctly placed cups with inclination (P = .046) and with anteversion (P = .006). Combining both anteversion and inclination, there was a significant difference (P = .01). We demonstrated a significant increase in accuracy of placement of acetabular cups within the desired position and safe zone using imageless navigation. Crown