Comparison of cemented vs uncemented acetabular component positioning using an imageless navigation system.

Hip navigation was used as an assessment tool to compare ability to reproduce trial and definitive acetabular placement in total hip arthroplasty, using cemented and uncemented components. We demonstrated a significant difference in reproducibility between components. Of 20 uncemented cups, 4 (20%) deviated from the target inclination by 5 degrees or more compared to none of 21 in the cemented group (P = .048). Of the 20 uncemented cups, 7 (35%) deviated from the target version by 5 degrees or more compared to none of 21 in the cemented group (P = .003). This may explain higher rates of revision for dislocation with uncemented components. There was also a significant difference between the groups with regard to deviation from planned leg length (P < .001).