Use of Imageless Navigation in the Conversion of Hip Fusion to Total Hip Arthroplasty.

Conversion of hip arthrodesis to total hip arthroplasty is associated with significant challenges, including accurate restoration of leg length and proper orientation of the acetabular component. Computer-assisted navigation provides real-time data on these parameters that may be a useful augment during hip fusion takedown surgery. Here, we present the case of a 64-year-old woman who presented with symptoms related to a left hip arthrodesis. The patient underwent a left-sided hip arthrodesis takedown and conversion to a total hip arthroplasty (THA). Due to the altered anatomical architecture of the fused hip, imageless navigation was used to assist with the conversion to THA. This case demonstrates that in complex hip arthroplasty procedures, where anatomical morphology is altered, navigation technology can be beneficial in addressing the challenges of achieving optimal placement of acetabular components and establishing appropriate leg length and offset.