Engineers, Vets Take Joint
Look at Horse Knees

November 19, 2003

By Andrew Vowles

Profs. Ludovic Bouré, Clinical Studies, Jeff Thomason, Biomedical Sciences, and John Runciman, Engineering, have joined forces to develop a novel veterinary teaching module designed to give students a three-dimensional virtual look at a horse's knee.

Equine knee ailments are a common and costly affliction, says Bouré, who studies laparoscopy and minimally invasive techniques in large-animal surgery. "It's a joint that gets a lot of injury. It's frequently injured in racing horses."

Yet those injuries are notoriously difficult to diagnose correctly. Holding a skeletal knee, Bouré points out the intricately detailed grouping of small bones. The problem is compounded for veterinary students learning to read a two-dimensional X-ray: Is that hairline a fracture or just a shadow?

The Guelph team's answer: Why not model that 3-D puzzle in three dimensions? And rather than stop at the bones, why not model the surrounding tissues all the way to the skin?

Working with Victor Sprenger, a master's student in biological engineering, the researchers are developing just such a 3-D computer model, one that Bouré plans to use as a module in teaching surgical anatomy and arthroscopic principles to veterinary students.

Work on the module began in 2002 with a two-year $100,000 grant from CANARIE. By fall 2004, the module will be used along with conventional diagnostic images to help students learn to pinpoint ailments accurately, Bouré says. Beyond that, the 3-D computer model might help in surgical training or be used by vets in planning arthroscopic surgery.

He believes building images and simulations of joint injuries is less a clinical problem than an engineering challenge. For his part, Runciman says biological engineers need to have "a little piece of the clinician inside us" to understand the nature of problems like this one. "That's why these collaborative projects work so well."

He and other biomechanical engineers at Guelph have worked with faculty in OVC and the Department of Human Biology and Nutritional Sciences on a number of studies.

In the current project, Sprenger is designing the 3-D computer module, including integrating the structures to enable a user to virtually dissect a horse's knee joint. Also involved are University of Montreal professor André Desrochers and Montreal 3-D artist Félix Roy, who will use colour and texture to make the image surfaces more realistic. (The software for the project was also used to produce animations for the movie The Lord of the Rings.)

On the screen of Sprenger's laptop, a gold-tinted 3-D image shows the joint's bones and ligaments down to a resolution of half a millimetre. He built that image by marrying MRI data acquired at the Lawson Institute in London with information from a technique developed by the Mississauga firm Applied Precision and used mostly by carmakers to provide co-ordinates of millions of points in space down to tenths of millimetres.

Called polarized white light scanning, the technique gave the Guelph researchers a picture of the surface contours of the joint and enabled them to map the motion of individual bones as well as cartilage and ligaments. Undergraduate engineering student Mark Kwiesinski helped process the MRI images and scanning data to pull out useful 3-D information.

They ended up with more data than needed. "It has to look realistic, but it doesn't have to be too realistic," says Sprenger.
He notes that no surgical simulations exist for equine knees. "Surgical simulators for human knees were one of the first to be developed because arthroscopic surgery on that joint is so common."

As an undergraduate, he worked on 3-D motion analysis in Runciman's biomechanical engineering design course, intended to give students a look at the science of medical implants and tools. Sprenger says that work gave him even greater appreciation of the intricacies of biomechanics, especially those of the human body - "the greatest engineering marvel of all."

He's intimately acquainted with the ability of the body to withstand various forces as a former two-time All-Canadian wrestler. On the way to winning the Canadian university championships in 1999 and silver in 2001, he earned his own share of injuries, including torn ligaments in his ankles and shoulders.

Sprenger planned to become a doctor when he entered U of G in 1996 as a President's Scholar. Drawn instead to engineering, he is combining both interests in biological engineering. Glancing at the image on his screen, he says this project has given him a different view of biomechanics. "It's an eye-opener."