When a horse has a severe case of laminitis with marked instability of the coffin bone, cutting the deep digital flexor tendon (DDFT) is a treatment that veterinarians often recommend. This surgical procedure is commonly done halfway down the back of the cannon with the horse standing and sedated, but researchers recently described a modified technique that is performed behind the pastern.
R. Wayne Waguespack, DVM, MS, Dipl. ACVS, assistant professor of clinical sciences at Auburn University, discussed the modified deep digital flexor tenotomy technique at the 2009 American Association of Equine Practitioners convention, held Dec. 5-9 in Las Vegas, Nev.
"Regardless of the site, the purpose of the tenotomy procedure is to remove the force that is primarily responsible for rotation of the distal phalanx (coffin bone) and pain associated with the laminar separation," he explained. The laminae attach the hoof wall to the coffin bone.
It's not uncommon for chronic laminitis cases to require another tenotomy, and having an alternate location free of scar tissue for the second procedure would be beneficial.
"The midpastern approach was first described in the literature in 1986, and (it was) done under general anesthesia through a 3-cm incision," he said. "The advantages of that technique are that you get good visualization of the tendon and about 10 cm of tendon release, but the disadvantages are general anesthesia and the size of the incision leads to concerns about sepsis (blood infection). The midcannon technique can be done with the horse standing and also has good visualization of the tendon, but the incision is small