OR8: PATIENT-SPECIFIC MODELLING FOR ORTHOPAEDICS: OPPORTUNITIES AND CHALLENGES

Abstract

Patient- specific orthopaedic models are currently used in computer navigation. They provide realistic 3-D geometries for assessment of device placement (e.g. tibial trays, hip implants). Models are generated at time of operation by the surgeon. But patient-specific models have other uses. We envisage a future in which realistic 3-D patient models are routinely used for predicting the outcome of surgical procedures and new devices and for general patient health monitoring.

We are currently developing accurate 3-D models directly from CT scan post-operation. They are being used in investigations of the progress of bone remodeling. Such work can provide valuable feedback on the outcome of new procedures and how bone remodels under load. Such models would eventually include other tissue such as muscles and skin.

But there are a number of research and development challenges associated with the creation of patient-specific models. They include

1. minimal use of radiation for data collection;

2. need for an automated method of generating patient specific models as clinicians (not engineers) should be able to create computer models easily and quickly;

3. need for improvements in computational efficiency. An ultimate goal would be to run simulations on computer hardware that is available to the clinician;

4. How to deal with missing data. We need techniques for supplementing patient data with data from a “model library”;

5. Research to provide techniques for dealing with multiple organs (muscles, skin and bone altogether).

We are working to meet these challenges. They include the use of generic data to supplement patient data, efficient ways of morphing models to fit the patient, and multi-scale modeling strategies. Work in progress at the Auckland Bio-engineering Institute will be presented in this talk.