Clinicians injecting or aspirating joints of the upper extremities should know that imaging is a more precise guide to the target than palpation—and that ultrasound offers potential advantages over other imaging modalities used as guides.
Researchers at UC-San Francisco make both cases in a literature review posted online Aug. 13 in Skeletal Radiology [1].
Corresponding author Rina Patel, MD, senior author Tara Morgan, MD, and colleagues present evidence supporting, for example, the superiority of ultrasound guidance over guidance with fluoroscopy because of ultrasound’s potential to identify effusions, soft tissue abscess or bursitis.
The team focuses on five clinical targets in which ultrasound deserves consideration for guiding injections of corticosteroids and contrast agents, as well as for joint aspiration in cases of suspected infection.
The specific joints they take up:
Glenohumeral (GH) joint. Both posterior and anterior approaches to ultrasound guidance for MR arthrography have proven successful for contrast injection, the authors show, suggesting the only point of dispute is which angle stands to bring more benefits. More:
In one comparison of ultrasound-guided anterior and posterior approaches for arthrography, the anterior approach was more successful with the first attempt and had shorter mean procedural time. In another study, there was no significant difference in procedural time comparing the anterior and posterior approach, although fewer incidences of contrast extravasation occurred with the posterior approach. Given the potential for contrast extravasation, a tailored approach depending on the indication for arthrography may be the best method.”
Acromioclavicular (AC) joint. Access of the AC joint using palpation and anatomic landmarks alone has variable accuracy and can be as low as 36.5%, Patel and co-authors state, citing two studies. By contrast, image-guided AC joint injections “are significantly more accurate … [and] ultrasound guidance significantly improves accuracy to 96%.”
Another comparison of AC corticosteroid injection by ultrasound guidance versus palpation showed significantly greater improvement in functional status and decrease in pain when ultrasound guidance was used. There has been no direct comparison of ultrasound versus fluoroscopic-guided AC joint interventions, although there are [several] benefits to using ultrasound guidance for joint aspiration.”
Sternoclavicular (SC) joint. Sternoclavicular joint intervention by palpation and anatomic landmarks “can be accurate,” Patel and colleagues point out. They write, “One study of injections in cadavers showed an overall accuracy of 78%, although accuracy of ultrasound-guided injections is up to 100%.”
Studies directly comparing different methods of intervention at the SC joint are limited. Image-guided SC joint interventions have been described by CT, fluoroscopic or ultrasound guidance.”
Elbow joint. The accuracy for ultrasound-guided injection ranges from 91% to 100%, the authors show, citing studies showing accuracy as low as 64% and as high as 100% for elbow injections performed without imaging guidance.
Ultrasound is well-suited to detect elbow joint effusion, and at least one study that included elbow and small joints found that ultrasound-guided aspirations were more successful than non-image guided aspiration (97% success versus 32% for palpation-guided).”
Wrist/hand joints. One cadaver study showed thumb carpometacarpal joint injections were significantly more accurate with ultrasound guidance (38% without vs. 72% with ultrasound, the authors report. In addition, ultrasound has proven a worthwhile guide when injecting contrast ahead of MR arthrograms of the wrist.
One study of contrast injections found that ultrasound-guided injections were significantly more accurate than those done by palpation (100% vs 72%). Although ultrasound and fluoroscopy had similar accuracy of 100%, ultrasound-guided injections were significantly shorter and less painful than fluoroscopic-guided injections. Ultrasound guidance may also be advantageous in patients with significant deformity or narrowing of the joint space from underlying arthritis.”
In concluding their report, Patel and co-authors acknowledge that injections of small joints may be performed safely and accurately without image guidance. However, they underscore, ultrasound guidance provides for “significantly higher accuracy at multiple joints of the upper extremity.”
“Furthermore, ultrasound has many potential advantages over other forms of imaging guidance, especially in the setting of possible joint infection,” they add.
For these reasons, they state:
Fully understanding and appreciating the many utilities of ultrasound for image-guided interventions of the upper extremity is crucial for the practicing radiologist.”
The study is posted in full for free.
Dave P. has worked in journalism, marketing and public relations for more than 30 years, frequently concentrating on hospitals, healthcare technology and Catholic communications. He has also specialized in fundraising communications, ghostwriting for CEOs of local, national and global charities, nonprofits and foundations.