Surgical Hardware: The Testing of the Screw
A headless, tapered screw made out of tough, lightweight metal could put a new twist on surgical implants used in pastern arthrodesis.
For years, riders in Western performance events such as reining, cutting, and barrel racing have
- Topics: Article, Other Veterinary Technologies
A headless, tapered screw made out of tough, lightweight metal could put a new twist on surgical implants used in pastern arthrodesis.
For years, riders in Western performance events such as reining, cutting, and barrel racing have encountered a serious problem with their horses’ pastern joints. Thanks to all those quick starts and stops that are required in Western-style events, older horses can develop a condition known as chronic osteoarthritis of the pastern joint.
Much like arthritis in humans, the condition causes chronic inflammation in the pastern joint–the joint that connects the long and small pastern bones. Horses that suffer from chronic osteoarthritis of the pastern joint can experience a great deal of pain, and in many cases, the condition can end a horse’s performance career.
The headless, tapered screw being tested at the University of Saskatchewan. |
Specialists have developed a number of different treatments to help relieve the pain. One of the most successful is arthrodesis (joint fusion), based on techniques used in human medicine. Veterinary surgeons generally use a combination of small screws and plates to fuse the horse’s pastern joint.
However, the exact combination of surgical implants has been the subject of a considerable amount of debate in veterinary surgery circles. “Early on, there really wasn’t any objective biomechanical assessment of these implants available to equine practitioners,” explained David Wilson, DVM, Dipl. ACVS, a professor in the department of Large Animal Clinical Sciences at the Western College of Veterinary Medicine, a part of the University of Saskatchewan.
Wilson is a veteran researcher who has conducted a number of biomechanical studies on surgical implants with research teams in Canada and the U.S.
“We got involved in testing these products because we wanted to shed some objective light on what we can expect mechanically from these different repairs,” Wilson said.
Over the past several months, Wilson and his surgical resident, Ryan Wolker, DVM, have been evaluating the strength and effectiveness of one particular implant: a headless, tapered titanium screw.
With the use of equine cadaver legs and biomechanical testing equipment at the University of Saskatchewan’s College of Engineering, the researchers have been examining whether these new screws are comparable to other screws with heads that are available to surgical specialists. If they stand up to the strain, that could be a good thing for horse owners. Wolker said studies have shown that titanium causes less inflammation inside the body than traditional stainless steel screws. As well, he said headless, tapered screws have been shown to decrease tissue irritation.
“Some reports in the 1980s and mid-1990s have suggested that with the two parallel screw technique (one of the recommended techniques for pastern arthrodesis), you get some irritation of the soft tissues around the joint and that can lead to excess bone deposition,” Wolker said. “Our thought is that if we can bury the headless screws entirely within the bone so there’s nothing exposed, we might be able to avoid those problems. The headless screws might turn out to be a good alternative to the traditional ones.”
Wilson concurred: “Because the screw is buried below the surface of the bone, there may be less potential for the tendon to be interfered with as it passes over the screws. It’s one suggestion that often comes up when people talk about why some horses don’t do well after pastern arthrodesis surgery.”
Large animal surgery resident Dr. Ryan Wolker (left) and Dr. David Wilson with one of the headless titanium screws TheHorse.com is home to thousands of free articles about horse health care. In order to access some of our exclusive free content, you must be signed into TheHorse.com. Already have an account? Written by: Stay on top of the most recent Horse Health news with © 2022 Copyright Statement dolor sit amet, consetetur sadipscing User Terms, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet. You need to be logged in to fill out this form |
