Related Experiment Video
Updated: Jun 25, 2026
Individualized Stem-positioning in Calcar-guided Short-stem Total Hip Arthroplasty
Published on: February 27, 2018
Measuring leg length and offset with an imageless navigation system during total hip arthroplasty: is it really
Tobias Renkawitz1, Tibor Schuster, Thomas Herold
1Department of Orthopaedic Surgery, Regensburg University Medical Centre, sklepios Klinikum Bad Abbach, Bad Abbach, Germany. tobias.renkawitz@web.de
Background:
A novel imageless measurement algorithm to assess leg length (LL) and offset (OS) changes during total hip arthroplasty (THA) has been established, the purpose of this study was to describe the process and establish whether or not it is accurate.
Methods:
THA was performed on 17 cadaver hip specimens. LL and OS changes were determined intra-operatively, using an imageless navigation system. Pre- and postoperatively, all specimens had a computed tomography scan (CT) and the LL and OS changes were analysed by two blinded investigators.
Results:
With mean differences of less than 1 mm (LL, 0.74; SD, 2.4 mm; OS, 0.89; SD, 1.8 mm) supported by substantial significant correlations [r = 0.83 (LL) and r = 0.92 (OS)] imageless navigation values demonstrated a high accuracy when compared to CT measurements.
Conclusions:
Intra-operative LL and OS measures are reliable and accurate when using an imageless calculation algorithm which stores the position of the femoral reference frame in relation to the pelvic coordinate system before and after reconstruction.
