SÃO PAULO, Brazil—New research shows that the overwhelming majority of blind intra-articular injections (IAIs), done without ultrasound guidance, in rheumatoid arthritis (RA) patients are accurate when performed by a trained rheumatologist. The new study appears online in Rheumatology.1

“The present study demonstrates that a trained rheumatologist can successfully perform blind [IAIs] in most peripheral joints of patients with RA.”—R.V. Lopes, MD
“The present study demonstrates that a trained rheumatologist can successfully perform blind [IAIs] in most peripheral joints of patients with RA,” concluded the study authors led by R.V. Lopes, MD, of the Universidade Federal de São Paulo in Brazil. “…however, optimization in the training of this procedure is a necessary part of the education of rheumatologists.”

The new study of 96 RA patients showed that the accuracy of blind IAIs varies by joints. Specifically IAIs in the elbow, wrist, metacarpophalangeal joints (MCP), and knees were more accurate than in the shoulder and the ankle. A trained rheumatologist performed the blind IAIs using triamcinolone hexacetonide. X-rays were taken before and after each injection using a contrast agent. Two “blinded” radiologists then classified the images according to the intra-articular or extra-articular localization of the contrast agent to determine accuracy.

A total of 232 IAIs were performed. The percentage of accuracy observed for the shoulder, elbow, wrist, MCP joints, knee, and ankle were 82%, 100%, 97%, 97%, 100%, and 77%, respectively. Blinded rheumatologists examined patients at baseline and at 1 and 4 weeks postinjection and found significant improvements in the visual analog scale for pain at rest, during movement, edema, and morning stiffness. The blind injections were also safe, the study showed.

The authors point out that the accuracy is higher than generally reported. Such factors may include that, unlike the present study which looked at multiple joints, most studies of blinded IAIs only assess a single joint. Furthermore, the new study comprised RA patients and the injections were performed by a well-trained rheumatologist with 10 years’ experience.

Translating research into practice

“Training in blind [IAI] is standard training for rheumatologists,” said Eric Matteson, MD, professor of medicine at the Mayo Clinic in Rochester, Minnesota. “Competence in this procedure is expected for completion of rheumatology fellowship training; [hence] most rheumatologists [in the United States] are trained in, and routinely perform, these procedures.”

Ultrasound and other imaging technologies do have a role in some injections, Dr. Matteson added.

“There is increasing use of ultrasound to better localize the injection site, a technique that is especially valuable for injecting ‘difficult’ joints like the shoulder and ankle, as well as the hip (not evaluated in the study). In addition, we perform a wide range of soft tissue injections [with ultrasound guidance], such as injection of bursae and tendon sheaths, which have poor accuracy when done blinded.”

“The yield of joint aspiration procedures is enhanced by use of ultrasound, and as well, using ultrasound helps to define pathology such as rotator cuff tears, bursitis, and the like. Blind injection of the joints that can be routinely accurately injected is effective therapy. Certainly, doing the procedure with imaging enhances the value of the procedure and the therapeutic results for the [above noted] circumstances,” he said.

Reference
1. Lopes RV, Furtado NV, Parmigiani L, et al. Accuracy of intra-articular injections in peripheral joints performed blindly in patients with rheumatoid arthritis.  [published online ahead of print September 27, 2008]. 2008. http://rheumatology.oxfordjournals.org/cgi/content/abstract/ken355v1.