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Updated: Apr 3, 2026

Individualized Stem-positioning in Calcar-guided Short-stem Total Hip Arthroplasty
Published on: February 27, 2018
Precision of acetabular cup placement in robotic integrated total hip arthroplasty
Leah Elson1, Jon Dounchis2, Richard Illgen3
1Harris Orthopaedic Laboratory, Massachusetts General Hospital, Boston, Massachusetts - USA.
Aims:
The aim of this study was to assess the efficacy of stereotactic-arm assisted acetabular component placement during total hip arthroplasty (THA).
Methods:
120 patients underwent primary THA at 4 different medical centres. A preoperative pelvic CT protocol was used to plan socket placement followed by robotic-arm assisted acetabular preparation and cup insertion. Intraoperative cup position was recorded and postoperative placement measured using Martell suite analysis software.
Results:
Using a 95% predictive intervals, robotic-arm cup placement was within +/-4 degrees of planned position in 95% of cases. Applying these data to the so-called safe zone, 96% of sockets were within the defined safe zone. Our data confirms that intraoperative robotic assistance improves the precision of preparation and position of the acetabular cup during total hip arthroplasty.

