Ultrasound imaging is used extensively; not only for diagnosing tendon and ligament injuries, but also to assess necks, backs, the pelvis, bone surfaces, joints and monitor a horse’s rehabilitation program. In 2012, Dr. Kleider received his ISELP certification which means that he is internationally accredited in this field of diagnostics, as it pertains to the musculoskeletal system.
Our Mylab30 Gold digital ultrasound is a portable technology with the ability to lower the screen to ground level enabling easier ultrasounds of the foot and pastern. Four different ultrasound probes enable us to view every location of the horse’s body. The addition of a second ultrasound machine enables our clinic to look at several cases at one time and use ultrasound in clinic and on the road.
Diagnostic ultrasound is equivalent to a sophisticated fish finder. Sound waves project through a liquid interface and either rebound or penetrate through various structures depending on their density. The waves are portrayed on a screen with dark areas generally indicating fluid or torn tissue and light areas indicating dense structures such as bone and tendon or ligament. Ultrasound waves do not penetrate through air therefore ultrasound gel or alcohol must be used to provide contact between the scan head and the tissue being examined.
The combination of ultrasound and x-rays is used frequently to provide more information in many areas. In the past bone problems were typically investigated with x-rays and ultrasound was relegated to investigate soft tissue issues. Significant findings on radiographs require 30% to 40% bone loss. We now know that ultrasound is more sensitive for assessing the surface of bone. X-rays do not allow viewing of cartilage and ultrasound can see cartilage even better than MRI!
Ultrasound studies tell us a number of things:
Which structure is involved – this is frequently accomplished by a careful physical exam and comparing with the other limb to look for asymmetrical structures.
The severity of the injury – ultrasounds shows swelling and disruption of tendon and ligament fibers.
The extent of the injury – ultrasound usually confirms the injury in two planes and follows the injury from stem to stern. This allows the owner to better visualize the extent of the problem.
The procedure requires mild sedation to inhibit movement and possible clipping the area if the horses’ hair is too long. Examination times vary depending on area involved. For example, the stifle area has six ligaments, two menisci, three joints and their corresponding articular surfaces which all have to be examined independently and is therefore considered a lengthy procedure. A bowed tendon usually indicates a superficial flexor tendon injury, so identifying the structure is not so much the issue as is quantifying the extent of injury and providing appropriate therapy.
Common Areas for Ultrasound studies:
– Puncture wounds
– Tendon sheaths
– Navicular region
– Pastern region
– High suspensory region
– Flexor and extensor tendons
– Carpal and tarsal sheath
– Chest for respiratory disease
– Skull, neck, back and pelvis
Ultrasound guided nerve, joint and bursa injections are now the standard technique used to ensure proper deposition of anesthetic or treatment solutions. In 2013, Dr. Kleider presented a technique he documented for ultrasound guided inject of the stifle joint at the AAEP annual conference in Nashville TN. The technique ensures that therapy is accurately and consistently injected into joint.