Related Experiment Video
Updated: Jun 25, 2026

Individualized Stem-positioning in Calcar-guided Short-stem Total Hip Arthroplasty
Published on: February 27, 2018
Tailor-made surgical guide based on rapid prototyping technique for cup insertion in total hip arthroplasty
Takehito Hananouchi1, Masanobu Saito, Tsuyoshi Koyama
1Department of Orthopaedic Surgery, Osaka University Graduate School of Medicine, Osaka, Japan. hana-osaka@umin.net
Background:
A surgical guide made by the rapid prototyping (RP) technique for cup insertion in total hip arthroplasty might be useful to avoid malalignment of the cup, which indicates postoperative complications.
Methods:
To address this research question, we applied a RP-based guide to 24 patients with their CT images. We designed it to fit onto the acetabular edge and to insert a Kirschner wire (K-wire) which indicated a planned cup direction. We intraoperatively placed it on the acetabular edge, inserted the K-wire through the guide on the superior acetabulum and implanted the cup while observing the alignment of the K-wire. We also recorded the additional time needed to use the guide.
Results:
The mean cup accuracy between planned and postoperative alignments was 2.8 degrees (SD = 2.1 degrees ) for abduction and 3.7 degrees (SD = 2.7 degrees ) for anteversion. The mean additional time was 3.5 (range 2-6) min.
Conclusion:
We can use this guide with acceptable accuracy and without consuming an excessive amount of time.
