Treatments for joint pain have multiplied as medical technology has advanced. One such advance is the replacement of traditional “blind” or landmark-guided injections (LMG) with innovative ultrasound-guided injections (USG) to treat joint pain and inflammation.
Studies show that USGs provide more accuracy of injection and greater improvement in both pain and joint function than LMGs.
Joint effusion (or swelling) is a common manifestation of a painful joint. The volume of joint fluid itself can cause pain, pressure, and there are substances within the fluid known as mediators of pain. A joint effusion can have many different causes (including synovitis from rheumatoid arthritis: a chronic inflammatory disorder that typically affects the small joints in hands and feet), the most common cause in an active, healthy person, is overuse or the early stages of cartilage degradation.
Effusions often resolve on their own. However, they can reoccur especially if the offending activity is continued. An effusion is often there though it is not necessarily painful. Frequently there is pain even without an effusion.
Doctors frequently find it useful to inject corticosteroid and/or local anesthetic medication directly into the joint or bursa communicating with the joint, in order to mitigate the inflammation and deliver pain relief. As it may make physical therapy more effective, reduction in pain is particularly useful and can likely restore function.
This procedure is most often used in the:
Therapeutic joint injections for pain management have been used for many years. The success rate and clinical improvement depends on the condition of the joint and the medication administered during the injection.
A logical contributor to success is the accurate placement of the medication into the intended location. Immediate benefits are often felt from the numbing medication, both patient and physician gain diagnostic insight before the visit is even over. The cortisone may take several days to build a therapeutic effect. Unfortunately, the duration of pain relief is highly variable. To make a proper diagnosis based off of an injection proper localization is critical, and ultrasound has a proven track record of adding accuracy to common injections.
Traditionally injections had been performed ‘blind’ (without image guidance) in the clinical setting. Some studies suggest (http://www.ncbi.nlm.nih.gov/pubmed/24534099) that even experienced clinicians have a difficult time identifying superficial joints.
These injections are called “landmark guided” because the physician will palpate boney landmarks as means of indirectly finding a joint with a needle.
With the advent of readily available imaging tools such as ultrasound, image-guided injections have become more routine. According to the American Association of Orthopaedic Surgeons, “The use of ultrasound to evaluate musculoskeletal structures was first reported in 1958. Since then, its use has grown exponentially, particularly in the office setting. Ultrasound enables physicians to reliably visualize soft-tissue structures … as well as identify any pathologic changes within these structures.”
In a study of hip joint injections published in The British Journal of Sports Medicine, Ultrasound Guided Injections were 100% accurate and LMGs were only 72% accurate. This disparity is noteworthy, but it isn’t the only study to replicate these results. Most tellingly, a study of cadaveric injection sites found that the landmark-based method was accurate 40 percent to 66 percent of the time, while fluoroscopic guidance and other image guidance yielded accuracy rates of 100 percent. Additionally, in a study of six papers that compared ultrasound guided injections and landmark-guided injections, there was a “statistically significant difference in favor of USG for pain at 6 weeks.”
Ultrasound guided injections have the capability to minimize complications and procedural pain with improved accuracy. Doing an ultrasound guided injection also gives an opportunity to revise the diagnosis prior to injecting as the physician will utilize the ultrasound to identify the optimal needle trajectory. Ultrasound aids in diagnosis, improves injection accuracy, makes for a less painful procedure and often saves a return visit for repeat injections, thus saving money and time resulting in improved patient satisfaction and expedited return to activities.