b'AAEP FORUM MATT LESHAW, DVMTheHorse.com/AAEP-ForumUltrasonographys Role in Lameness CasesU ltrasonography has become onesometimes cell- and protein-rich fluid. of the most versatile field imagingEvaluating synovial fluid and lining modalities for evaluating equinecan provide insight into inflammation musculoskeletal injuries because it allowsseverity. Additionally, veterinarians can veterinarians to visualize almost any bodyexamine joint cartilage for defects caused tissue, most importantly soft tissues suchby traumatic injury or OCD. as tendons and ligaments.Almost as important as making a COURTESY DR. JOHANNA REIMERUltrasound uses high-frequency sounddiagnosis with ultrasound is treating and waves to produce images in real time.monitoring injuries with it. For tendon The user holds a sound-wave-emittingor ligament tears, for instance, veterinar-probe against the skin toward the struc- ians can administer regenerative products ture being evaluated. When the wavessuch as stem cells or platelet-rich plasma meet structures or interfaces betweendirectly into the region of fiber disrup-structures, they reflect back to the probeLarge, centrally located regions of tendon fibertion under ultrasound guidance. They like a ships sonar. The more abrupt thedisruption like this one are called core lesions.insert a needle in the ultrasound beam interface or dense the structure, the moreso they can visualize penetration depth waves reflected. The more sound wavesdark area within it. Dark regions repre- and see the therapeutic as it enters the received, the brighter the structure lookssent fiber disruption, or voids, where nospace. Veterinarians can treat other areas, on-screen. We describe brightness insounds waves reflect. Larger, centrallysuch as the sacroiliac, thoracolumbar terms of echogenicity. For example, bonelocated regions of fiber disruption areand cervical facet joints of the spine, with appears bright (echogenic), normal fluidcommonly referred to as core lesions.anti- inflammatory agents via ultrasound is dark (nonechogenic), and all otherViewing this same regions longitudi- guidance, without which theyd be doing structures show up somewhere between.nal axis, with the probe along the lengthit blindly and potentially too distant from With regard to lameness issues, yourof the tendon or ligament, the normallythe pain site to be effective. Ultrasound veterinarian is most likely to use ultra- long, linear fibers might appear short andguidance also ensures the needle doesnt sound to assess tendons and ligaments,choppy or be missing altogether. Abnor- inadvertently penetrate other structures. bone surfaces, synovial fluid, and car- malities are not always as overt, and trueAfter injury or treatment, veterinarians tilage. Think of tendons and ligamentsinjuries could be as subtle as small, darkperform follow-up clinical and ultrasound as ropes made up of many strands orlinear striations or mildly abnormal edges.exams to assess healing. They look for de-fibers. Tendons connect muscles to bones,Ultrasound waves cannot penetratecreases in cross-sectional area, increases while ligaments connect bones. Whenbone, but veterinarians can use them toin echogenicity, and improvements in tendons or ligaments are strained, theirevaluate its surface. Due to bones density,fiber alignment in tendon and ligament fibers might tear. Veterinarians assess theit should look like a bright, white, smoothinjuries. Ultrasonographic improvement extent of tendon or ligament damage byline on the screen. Bone surface changesand clinical improvement together guide evaluating its size, echogenicity, and fiberat tendon or ligament insertion sites orrecommendations to increase the horses pattern. Often, minor tendon or ligamentaround arthritic joints, fractures, or osteo- workload. injuries result in an increase in size, orchondritis dissecans (OCD) lesions causeThe portability, versatility, and accuracy cross-sectional area. In cases of significantthese lines to look disjointed and/or rough.of todays machines make ultrasound an disruption, veterinarians might noticeEvaluating characteristics within sy- incredibly useful tool. With it vets can changes in echogenicity and fiber pattern.novial structures (joints, tendon sheaths,image any tissue to determine diagnosis, Normally, the echotexture or pattern- and bursas) can be similarly useful.while helping owners save money and ing of a tendon or ligament is homog- Normal structures have linings thattime. It can also help guide placement of enous (the same throughout); a perpen- produce a small amount of lubricating,therapeutic agents and allow monitoring dicular view of a normal tendon showsnutrient-rich fluid. With inflammationof recovery. If your practitioner suggests a round or ovoid structure with uniformfrom tendonitis, arthritis, direct trauma,using ultrasound on your horse, knowing shading. A damaged tendon might appearor any other type of irritation, the liningits uses, mechanics, and limitations can round and bright (normal fibers) with aproduces excessive, poor-quality, andhelp provide clarity during the process.hAmerican Association of Equine Practitioners, 4033 Iron Works Parkway, Lexington, KY40511859/233-0147www.aaep.org10December 2019The Horse|TheHorse.comAAEPForum_pg.indd 10 11/4/19 3:11 PM'