b'STEP BY STEPdriven by an imbalance of the osteoclastand osteoblast cells, Conway explains. Osteoblasts, which are cells that lay down new bone fibers, are overpowered by the osteoclastic activity in many horses with podotrochlosis. Bisphosphonates work on down-regulating osteoclasts by stopping their energy supply and, thus, encouraging a shift back to an equilib-rium state within bone, he says. The two bisphosphonate products on the North American market are tiludro-nate disodium (Tildren) and clodronate injection (Osphos). Conway says his first experience with bisphosphonates backAs a last resort, veterinarians SHELLEY PAULSONin 2014 was eye-opening. Within threemight perform a palmar digital to four weeks of administering Osphosneurectomy to sever the nerves that sensitize the hoof.to a horse with chronic navicular pain that was consistently mildly lame, he saw a dramatic decrease in lameness grade.Palmar digital (PD) neurectomy Often(anarthroscopic evaluation) gives the Within two months, that horse had re- considered a last resort, a PD neurectomysurgeon a total view of the navicular turned to barrel racing competition.is a procedure to cure lameness inapparatus. Upon visual inspection, the the navicular horse. The palmar digitalsurgeon can debride any adhesions from Joint Injectionsnerves run along both sides of the limb tothe DDFT or navicular bone.The injection of corticosteroids andinnervate the hoof, including the navicu- Bo Brock, DVM, owner of Brock hyaluronate directly into a joint can offerlar apparatus. The procedure is a simpleVeterinary Clinic, in Lamesa, Texas, says comfort to horses of all breeds and disci- transection (cutting) of the PD nerves,patients that were chronically lame and plines, even old pasture pets.essentially desensitizing the entire hoofend-stage have undergone bursoscopies Veterinarians commonly inject thebelow. When other treatments have failedwith great success at his clinic. Some have coffin joint and/or navicular bursa ofto manage the lameness, a neurectomyeven returned to work. Of course, it is not podotrochlosis horses. Coffin joint injec- might be the next best step. However, ita perfect fix. These horses always need to tions help reduce inflammation in thedoes not come without risk.have shoeing manipulations or cortico-joint caused by disruption of the navicu- Andy Kaneps, DVM, Dipl. ACVS,steroid injections, but sometimes theyre lar apparatus. Again, the navicular bursaACVSMR, owner of Kaneps Equinebeing used again for years, he says.acts as a cushion to prevent the DDFTSports Medicine and Surgery LLC, inDiagnostics have improved dramatical-from abrading itself on the bone. WhenBeverly, Massachusetts, has performedly in equine medicine, maybe even faster veterinarians begin to see radiographicmany neurectomies in his decadeslongthan treatment options. For years, weve changes in the navicular bone or DDFT,career.been able to diagnose (podotrochlosis) injecting the bursa with corticosteroidsCommon risks include incompletebetter than we can treat it, says Brock. might provide significant relief.desensitization of the heels and painfulBut with the advent of MRI, surgeons While joint injections can provideneuroma formation, he says. A neuromacan finally recognize and treat early quick relief directly to the diseased area,is a disorganized bundle of nerve fiberssigns of the condition with much more their duration of effect differs in everysecondary to transection that can besuccess. Brock has started performing horse. Some horses relief can last a yearincredibly painful. bursoscopies on horses developing early or more, others six months or less. WhileFurthermore, even if the procedureadhesions seen on MRI. Bursoscopy is injections provide fast and sometimeswas successful initially, the nerve mightthe only thing you can do that separates lasting benefits for lame horses, they doreinnervate the area, once again causingthe adhesion, he says. You have to go in nothing to treat the underlying disease. lameness. The positive effects may lastphysically and cut it.as short as two years, but often last for Surgical Optionsmany years longer, if not indefinitely,Take-Home MessageSurgical options to address soundnesssays Kaneps. While veterinarians canPodotrochlosis is and will continue issues associated with podotrochlosis arerepeat the surgery, the procedure mightto be a frustration for owners, farrier, an ever-growing area of research. Veteri- be less successful the next go-round.and veterinarians. It can be blind to age, narians are publishing new techniquesBursoscopy A relatively novel proce- breed, and discipline. With the advent of every few years. Here well focus on thedure gaining traction in North America isadvanced imaging, promising medical most common and researched techniquesnavicular bursoscopy. Its also consideredmanagement, and new surgical proce-for navicular pain: palmar digital neurec- an end-stage option when all otherdures, however, our hopes for horses with tomy and navicular bursoscopy.therapies have failed. The procedurethe condition have never been higher.h30January 2020The Horse|TheHorse.comSBS_Jan_use.indd 30 12/4/19 1:58 PM'