SNOWMASS, COLO. — You may be confident that you've got great hands for performing joint injections and aspirations, but the scientific evidence shows that unless you're using sonographic needle guidance, you're not nearly as good as you think.
Numerous studies have demonstrated that even skilled rheumatologists and orthopedic surgeons fail to place their needle tip in the intra-articular space 50%-60% of the time when they use palpation to guide injections, Dr. Eric L. Matteson said at a symposium sponsored by the American College of Rheumatology.
To make his point, Dr. Matteson cited data from a recent multicenter randomized trial involving ultrasound- or palpation-guided intra-articular steroid injections of 148 painful joints (mostly knees, wrists, shoulders, hips, elbows, wrists, and ankles). The ultrasound-guided group had 44% less procedural pain and a 59% greater reduction in pain at the 2-week follow-up than did the palpation group. Sonographic needle guidance also resulted in a 337% increase in the volume of aspirated fluid (J. Rheumatol. 2009;36:892-902).
“There's no question that ultrasound-guided injections are more accurate in certain joints, such as the deeper joints like the hips, the small joints of the hands, and the subacromial bursa,” said Dr. Matteson, professor of medicine and chief of the division of rheumatology at the Mayo Clinic, Rochester, Minn.
As a practical matter, he is quick to turn to ultrasound guidance in patients who are obese, have failed prior injections or aspirations, have experienced significant pain with prior injections, or have difficulty assuming the proper position for standard injections.
Since taking up musculoskeletal ultrasound half a decade ago, Dr. Matteson said he has become a huge fan. He uses it not only to guide procedures, but also as a dynamic extension of his clinical examination. Dr. Matteson reported that in his experience, musculoskeletal ultrasound is of great assistance in the diagnosis of tendon ruptures, synovitis and tenosynovitis, bursitis, effusions, soft tissue nodules, erosions, and the assessment of disease activity.
The use of office ultrasound to assess the hip joint is particularly noteworthy. This assessment is something that otherwise would often require a referral to radiology.
Another area in which musculoskeletal ultrasound has been a real breakthrough is in assessing the cause of shoulder pain. Ultrasound can readily visualize impingement, biceps tendon dislocation, acromioclavicular and sternoclavicular joint pathology, synovitis, and bursitis, as well as adhesions, calcifications, and rupture of the rotator cuff.
“Here I think ultrasound is a great boon to us in our practice. Assessing causes of shoulder pain is really a fantastic application,” he continued.
Patients love seeing their anatomy on the ultrasound screen; it turns their office visit into an educational experience, according to Dr. Matteson. Musculoskeletal ultrasound is a great teaching tool for medical professionals, as well.
“It's something that creates excitement among the fellows and medical students and residents who rotate through,” he said.
Indeed, a move is afoot to develop a curriculum for rheumatology fellows that will enable them to demonstrate competence in the technique.
Musculoskeletal ultrasound is rather well reimbursed under CPT billing codes 76880 and 76942, which were set by radiologists. Although it's possible to spend $100,000-$200,000 on an ultrasound machine, doing so is entirely unnecessary. A very good machine can be purchased for $40,000. The major equipment manufacturers typically sell demonstration models after a year's light use for considerably less.
Ultrasound probes that cover 5-13 MHz best serve rheumatologists' purposes, providing the required balance between penetration and resolution that permits the imaging of both deep structures like the hip and superficial ones like fingers.
The U.S. rheumatologist ultrasound interest group is reachable at www.msk-uss.org
Disclosures: Dr. Matteson indicated he has no relevant financial interests.
To view an interview with Dr. Matteson, go to www.youtube.com/rheumatologynews
Ultrasound shows synovial fluid (black) with needle approaching from right in a knee aspiration in an obese patient.
Source Courtesy Dr. Eric L. Matteson