Project

Hip Replacement Surgery Simulator

A bimanual VR simulator for total hip arthroplasty that renders the high forces of reaming and broaching with haptic feedback, so orthopedic residents can practice before they operate on patients.

The patented hammering force feedback device in action at DIVR 2023

01Overview

Total hip arthroplasty is one of the most successful orthopedic procedures, but the forces involved — the hammering, reaming, and broaching of bone — are difficult to practice safely. HIPS simulates the full procedure in virtual reality with two haptic devices, one for each hand, delivering realistic high-force feedback in real time.

The simulator builds on a cadaver-based biomechanical model of acetabulum reaming, so the haptic sensation reflects measured, real-world tissue behavior. High-force haptic rendering that stays stable at bimanual interaction rates was a central research challenge.

Part of the CGVR research program at the University of Bremen: project page at Uni Bremen →

02The procedure, step by step

Since 2023 the simulator covers all five steps of hip arthroplasty, each with its own haptic challenge:

Cutting off the head of the femur

Osteotomy with a powered saw and high, constant cutting force.

Reaming the acetabulum

The most difficult step — surgeons rate it hardest to learn, because the right amount of force and duration can only be felt. Ream too far and you damage bone or, worse, major arteries.

Implanting the hip socket

Hammer impact with the patented force feedback device — impact force and bone contact must be felt precisely.

Rasping a cavity into the femur

Hammer-driven broaching until the rasp fits the medullary cavity.

Implanting the joint

Final hammer impact to seat the femoral implant firmly.

03Videos

The DYNAMIC HIPS research project, in brief.

Rigid-body-based simulation of hip reamer and pelvic bone with material removal.

An orthopedic surgeon trying out the simulator.

Recording of the first working version, with English subtitles.

04The technology

Real surgeon tool mounted to the KUKA iiwa robot

Up to 137 N of force

A KUKA LBR iiwa robot renders extremely hard contacts. Real surgeon tools mount directly to the end-effector.

Density distribution in the acetabulum

Cadaver-based model

The haptic model reflects measured tissue behavior: density maps from cadaver acetabulums, red parts hard, green parts soft.

Visualization of a poorly reamed hip socket

Inner sphere trees

A novel collision detection structure based on sphere packings keeps haptic rendering stable at high forces and interaction rates.

05Awards

DIVR-Award for best tech

Among 100+ participants from all over Europe.

DIVR-Award for best tech

Among about 50 participants.

IEEE VR Honorable Mention

For the HIPS journal paper presented at IEEE VR 2025.

Best Application Paper Award

EuroVR 2020, for the review of haptic rendering techniques.

06Gallery

Receiving the DIVR-Award 2023 — Receiving the DIVR-Award 2023 for best tech. (Photo: divr.de)

Receiving the DIVR-Award 2019 — Receiving the DIVR-Award 2019 for best tech. (Photo: Mediennetzwerk.NRW / Juliane Herrmann)

Demo setup in Chemnitz with real surgeon tool — Evaluation with experienced surgeons in Chemnitz, May 2018 — real surgeon tool on the KUKA iiwa.

Surgeon testing the simulator — A surgeon testing the simulator in Chemnitz, May 2018.

Demonstration at the European Robotics Forum 2018 — Demonstration at the European Robotics Forum 2018 in Tampere, sponsored by KUKA.

The demo setup presented at IEEE VR 2018 — The same setup was presented at IEEE VR 2018 in Reutlingen.

Visualization of the density distribution in the acetabulum — Density distribution in the acetabulum — red is hard, green is soft.

Visualization of a poorly reamed hip socket — Visualization of a poorly reamed hip socket; colored parts are errors.

Under-reamed material in blue — Blue parts visualize under-reamed material — unhealthy bone or cartilage.

Over-reamed material in red — Red translucent parts show over-reamed material that weakens the bone.

07Key Results

Over a dozen surgeons confirmed the realism of the haptic sensation, and nearly all who tried it recommend the simulator for training students and resident surgeons.
Presented at IEEE VR 2025 with an Honorable Mention; journal version published in IEEE Transactions on Visualization and Computer Graphics (2025).
The underlying haptic rendering methods were validated in a replication study of perceived realism for bimanual high-force tasks (Scientific Reports, 2023).

08Related Research

09Press & reports

Interview "Hüftendoprothesen: OP virtuell und mit Gefühl trainieren", MEDICA online magazine, 2021
"OP-Training dank VR", MDR, 2020
Hip implant simulator for virtual surgery training, Tectales