# Implementation of an Intraoperative Augmented Reality Environment for Custom-Made Partial Pelvis Replacements—A Proof of Concept and Initial Results

## TL;DR

This study shows that using augmented reality during surgery for custom-made pelvis replacements can improve accuracy, though it increases stress for the surgical team.

## Contribution

The first intraoperative use of AR for custom partial pelvis replacements in revision arthroplasty is demonstrated.

## Key findings

- AR enabled implantation in all 11 cases with a mean COR deviation of 4.2 mm.
- The cup plane deviation angle averaged 4.4°, and the implant superimposition scored 0.69 (Dice-Score).
- AR improved intraoperative feedback but increased stress for the surgical team.

## Abstract

Background: The use of augmented reality (AR) in orthopaedics is growing rapidly but is mainly limited to pre-operative planning and teaching. This study is one of the first to describe the intraoperative application within revision arthroplasty for the positioning of customised partial pelvic replacements. Methods: In a proof-of-concept study an AR environment was used during surgery in 11 cases to enhance implant positioning. Postoperatively, a voxel-based CT deviation analysis was carried out to determine the COR deviation and the cup plane deviation angle. Additionally, digital implant superimposition was conducted. Results: Implantation was possible in all cases with a mean COR deviation vector of 4.2 (SD 2.5; 1.2–9.3) mm and a cup plane deviation angle of 4.4 (SD 2.5; 0.7–8.1)°. The implant analysis showed a superimposition of 0.69 (SD 0.15; 0.38–0.88) (Dice-Score calculation). Conclusions: This study is able to report promising results for AR in orthopaedic surgery, showing improved intraoperative feedback in complex operations, resulting in increased accuracy. However, the integration of AR poses a new challenge to the surgical team, especially because the AR users are facing a significantly increased level of intraoperative stress. Further development of this auspicious tool, as well as a conceivable combination with navigation, is necessary to facilitate broader usage.