Because it is relatively inexpensive, inherently safe, and seems to work, musculoskeletal ultrasound (MSUS) has been widely adopted in rheumatology without high-quality evidence to demonstrate its effectiveness. Now the American College of Rheumatology (ACR) has issued an evidence-based review of 14 scenarios in which MSUS is “reasonable,” and one scenario in which it is not.
MSUS can reduce the need for plain radiographs, CT and MRI scans, the recommendations say. Sometimes, as in evaluating the parotid and submandibular glands in Sjögren’s disease, MSUS is preferable. The recommendations are published in Arthritis Care & Research.
A review panel headed by Timothy McAlindon, MD, MPH, of Tufts Medical Center, Boston, used the RAND/UCLA methodology, designed to evaluate medical technologies where the literature base is incomplete. Dr. McAlindon and John FitzGerald, MD, PhD, of the University of California, Los Angeles, who also served on the panel, will be giving presentations on the new standards in a clinical symposium (“Should Ultrasound Be Used in Rheumatology Practice?”) next Tuesday at the ACR annual meeting.
The panel didn’t evaluate costs, but noted a few cost/benefit studies demonstrating MSUS to be less expensive. MSUS-guided knee injections are less expensive than palpation-guided injections, and diagnostic MSUS is often less expensive than MRI.
Evidence deemed Level A was supported by at least two randomized clinical trials or at least one meta-analysis of randomized trials. Level B evidence was supported by one randomized trial, non-randomized studies or meta-analyses of non-randomized studies, and expert consensus opinion, case studies, or standard of care were rated as Level C. Among the recommendations, the panel deemed it “reasonable” to use MSUS for:
• further elucidating diagnosis for a patient with articular pain, swelling or mechanical symptoms in the absence of definitive diagnosis on clinical exam, for the following joints: glenohumeral, acromioclavicular, sternoclavicular, elbow, wrist, metacarpophalangeal, interphalangeal, hip, knee, ankle, midfoot and metatarsophalangeal. (Evidence level B)
• assessing inflammatory disease activity for a patient with diagnosed inflammatory arthritis and new or ongoing symptoms but no definitive diagnosis on clinical exam. MSUS can detect erosions, synovitis, and enthesitis that was not evident on plain radiographs. (Evidence level B)
• facilitating clinical assessment when evaluation is complicated by adipose or other local derangements of soft tissue, for patients with symptoms in the regions of the following joints: glenohumeral, acromioclavicular, elbow, wrist, hand, metacarpophalangeal, interphalangeal, hip, knee, ankle/foot, and metatarsophalangeal joints. (Evidence level C. )
However, MSUS should not be used to evaluate giant cell arteritis. The sensitivity is only 68-75%, the use is too infrequent to develop proficiency, and the consequences of missing a diagnosis are too great.
The recommendations assumed that ultrasound will be performed by trained operators, but the certification process for these skills is only beginning in the US. The American Registry for Diagnostic Medical Sonography is setting up a certification program, but not one that is focused specifically on point-of-care MSUS, and not one specially designed for rheumatologists. So the panel recommended creating a certification process focused on those issues.