Computer System Helps in Foot Surgery

Computer-assisted surgery (CAS) with a passive optical tracking system is the new future for repairing internal hoof fractures, providing highly accurate placement of screws and the chance for "perfect" results, according to a new study by Swiss researchers.

Navicular screw

CAS with Vetgate guided veterinary surgeons for the perfect placement of this 3.5 mm screw in a navicular bone.

Equipped with two infrared cameras that capture data coming from light emitted by trackers, "VetGate" is a new CAS system allowing for fine precision when dealing with the delicate bones of the equine foot, said Cornelia Schwarz, DVM, researcher in the department of equine surgery at the University of Zurich. As a result, surgeons are now able to repair navicular and coffin bone fractures with relatively wide screws, thus obtaining better stability of the fracture. For coffin bone fractures, they are also now able to use two screws instead of one.

"Generally, you always want at least two screws to stabilize a fracture because with only one, the fracture is not stable against rotation," Schwarz said during the presentation of her research at the fifth annual Swiss equine research day on April 30. "But in these very small bones, it's already a challenge to apply just one. Placement is extremely tight, and precision is key."

Screws that are set even slightly off the mark could put pressure on the joint or other delicate structures, which could lead to lameness or subsequent arthritis, she added.

During her study, Schwartz investigated the placement of two different sizes of screws into the internal hoof bones of 20 cadaver hooves using the VetGate CAS system. After surgery, the hooves were dissected for the evaluation of placement, pressure, and accidental penetration of other tissues. Results were also compared to a similar 2007 study using the SurgiGate system.

"The results were really amazing," said Schwarz. "We are very happy that we are now able to place one 3.5 mm screw into the navicular bone and two 4.5 mm screws into the distal phalanx without penetration of the joint surface. Placement was essentially perfect." None of these screws caused any pressure or complications to any other tissue and were aligned exactly as intended, she said.

"The Vetgate CAS system was the most precise system we have seen yet," said Schwarz, whose research won an award in the category of equine surgery. "It's far better than the previous methods described in 2007." An added benefit, she said, is that the technique will probably be much less expensive to use.

More from the 2010 Swiss Equine Research Day:

About the Author

Christa Lesté-Lasserre, MA

Christa Lesté-Lasserre is a freelance writer based in France. A native of Dallas, Texas, Lesté-Lasserre grew up riding Quarter Horses, Appaloosas, and Shetland Ponies. She holds a master’s degree in English, specializing in creative writing, from the University of Mississippi in Oxford and earned a bachelor's in journalism and creative writing with a minor in sciences from Baylor University in Waco, Texas. She currently keeps her two Trakehners at home near Paris. Follow Lesté-Lasserre on Twitter @christalestelas.

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