b'YOUR GUIDE TO THE 2017 AAEP CONVENTION SPONSORED BYGrade 1 to 3 lame (out of 5) on one leg.All horses had MRI evidence of aA B Csagittal groove injury, Gold said, but the characteristics varied:Three had osseous cystlike lesions (a bone defect or abnormality); Eight had subchondral (the layer below the joint cartilage) bone loss;Four had incomplete midsagittal frac-tures (cracks), near the center of the bone; andFour had high fluid signal intensity (lighter color on MRI) of the grooves subchondral and trabecular bone (indi-cating fluid in the bone).COURTESY DR. SARAH GOLDVets took radiographs in 13 horses to In Dr. Sarah Golds study, some osteochondral cystlike lesions in the subchondral bone of the sagit-compare results to the MRI, she said.tal groove were less visible on radiographs (left, center) than on MRI (right).They found apparent abnormalities in just six horses radiographs. Gold said 15cystlike lesion in the groove, and threeResearchers on previous studies saw horses had fetlock joint osteoarthritis. persistently lame horses had subchondralbetter outcomes for sagittal groove Practitioners had treated 18 horses con- bone osseous cystlike lesions.injuries in racehorses, she said, but this servatively and sent one horse to surgery. In eight horses diagnosed initially withcould indicate these horses experience a At follow-upon average, 29 monthsabnormal pastern signal, lesions weredifferent pathologic (disease or damage) after diagnosisGold said six horsessmaller, but only two of these animalsprocess than sport horses. Horses in this (31.5%) had returned to their prior usewere sound at follow-up. In horses withstudy might have experienced chronic and 13 (68.5%) remained unsound. All un- ill-defined subchondral bone loss at thejoint trauma and a delayed diagnosis sound horses blocked to the fetlock joint.sagittal groove, lesions were smaller inor might have had arthritis prior to the Two horses with incomplete fracturesfive horses, unchanged in two, and moresagittal groove trauma, Gold said. Both had healed and their lameness resolved.extensive in one. Concurrent fetlock jointcould have complicated healing.Two of the lame horses fractures hadosteoarthritis was worse in three horsesBased on this sample, the prog-not healed or they developed an osseousand remained unchanged in 12. nosis for performance soundness in Which PSD HorsesSciences, in College Station, saidinclude neurectomy of the deepultrasound two months after vets have a better understandingbranch of the lateral plantarsurgery to look for iatrogenic Are Good Hind- of the disease and diagnosticnerve (cutting the nerve) and(inadvertently caused by the Limb Neurectomyblocks than they had historically,fasciotomy (ligament splitting). clinician) lesionswhich can along with access to improvedWatts shared these tips foroccur but dont appear to affect prognosisand/or new injury. This Candidates? imaging (ultrasound and MRI). selecting surgical candidates:Proximal suspensory desmitisEven when equipped with Ensure an accurate diagnosis.exam also affords an opportunity (PSD) can sideline horses forthese advances, selecting theBe sure the suspensory injuryto get new baseline images.months. Hind-limb cases canright patients for surgery doesntis chronic. Performing surgeryWhen cases are selected be especially challenging tocome without challenges. Wattson acute cases leaves horsesappropriately, the complication reviewed which horses shouldat risk for developing veryrate is very low and the prognosis manageconservative treatment has a poor prognosis, and whileand shouldnt go under the knife. severe, chronic PSD afterward.for a full return to work is very surgery generally produces betterProximal suspensory desmitis Do not send horses withgood, with approximately 80% of results, not all horses are candi- is inflammation and tissue dam- hyperextended hind-limb andhorses returning to the previous dates. The good news? Vets canage in the upper part of the sus- hock conformation to surgery.level of work for at least one carefully select surgical cases topensory ligament that connectsThis conformation is knownyear, Watts said. It has been our improve outcomes.to the top back of the cannonto significantly increase theexperience and that of others Ashlee Watts, DVM, PhD, Dipl.bone and the proximal sesamoidrisk of catastrophic failure ofthat when the horse responds ACVS, an assistant professor ofbones at the back of the fetlock.the suspensory apparatusfavorably to fasciotomy and neu-large animal surgery at the TexasTraditional treatment involves stallfollowing fasciotomy andrectomy, the long-term outcome A&M University College of Vet- or pasture rest with or withoutneurectomy, Watts said.beyond one year is excellent.erinary Medicine & Biomedicalmedical therapies.SurgeriesVets should conduct a recheckErica LarsonA18 TheHorse.com/AAEP2017 AAEP Wrap-Up THE HORSEMarch 2018'