Injections are commonly utilized in sports medicine and orthopedics to aid in the diagnosis and treatment of a variety of musculoskeletal conditions. Commonly injected medications include cortisone, local anesthetics, and other products like hyaluronic acid or platelet rich plasma (PRP). In many cases, delivering an injection accurately to the target site is not as easy as it sounds. Just as people come in all shapes and sizes, our joint anatomy can be variable and sometimes difficult to accurately localize by visualization or palpation alone. Many times, the slimmest margin of error can determine if an injection works or doesn’t.
Traditionally, injections were given based on palpation guidance. This is sometimes considered “blind” because the absence of imaging guidance requires a doctor to have a great degree of experience and anatomical knowledge. Even with that training and skill, there was still for certain joints especially medium and small joints no guarantee of success.
Now with ultrasound for image guidance, an injection can be performed much more accurately and carefully placed into the correct joint or soft tissue. Ultrasound uses a live image to track the needle and allows direct guidance of the needle to the target while avoiding other nerves and blood vessels resulting in less risk of damage to those structures. Additionally, ultrasound can allow for greater effect with lower doses of medications like corticosteroids because of the enhanced precision.
Providing ultrasound guided injections requires a knowledge of the individual's anatomy and understanding the two-dimensional anatomy on ultrasound. A highly skilled medical professional trained in ultrasound guided injections can carefully deliver a targeted injection to superficial small joints like fingers and deep large joints like the hip.
Depending on the location, some studies have shown palpation injections to only be accurate 40% of the time, while ultrasound guided injections to be accurate 99% of the time. Another great benefit of ultrasound guided injections are that many studies have also shown ultrasound guided injections to be less painful.