Although image-guided placement of corticosteroid injections is more accurate than the use of anatomic landmarks, such guidance may add minimally, if at all, to treatment outcomes, according to an editorial by Australian researchers that appeared in the September issue of Annals of Rheumatic Diseases.

"Any added benefit in patient outcome achieved by a radiologically guided approach will need to be considered in light of the added expense of the imaging modality used," the authors wrote. "Although some rheumatologists may use office ultrasound, it is likely that in community practice it will be radiologists who employ ultrasound and other imaging techniques to administer injections." Adding the radiologist to the mix "may be associated with significant increase in overall health costs," they added.

To determine whether image-guided injections produce a superior outcome, the authors called for data from well-designed, randomized, controlled trials with long-term follow-up.

"Needle placement is more accurate, but it is still not clear whether it improves outcomes and whether it is cost-effective in comparison to anatomically guided injection," corresponding author Rachelle Buchbinder, MD, told CiaoMed. "We should be cautious in advocating image-guided needle placement over anatomic landmark placement for most procedures until we have proof that it is more effective and more cost-effective."

Dr. Buchbinder is an Associate Professor of Clinical Epidemiology at Monash University in Melbourne, Australia, where she is the Director of the Monash Department of Clinical Epidemiology at Cabrini Hospital. She noted that in some situations, such as intra-articular injection of the hip, an anatomical landmark is not appropriate; in such settings, image-guided placement would be preferred.

She and her co-author pointed out that corticosteroid injections have been used to treat arthritic joints since 1950. However, for the first 40 years that the injections were utilized, investigators did not methodically study the accuracy of needle placement. Since the 1990s, computed tomography (CT), ultrasound, and magnetic resonance imaging (MRI) have been used to guide needle placement, after investigators found that a high rate of injections intended to be intra-articular were, in fact, extra-articular, with such inaccuracies estimated to occur in 20% to 50% of cases.

The improvement in accuracy associated with image guidance is unquestioned. However, "the question arises as to whether guided injection produces a significantly different result from injections administered using anatomical landmarks," they wrote. They cited several studies, some of which showed an advantage to image guidance and others that demonstrated similar results in patients in which anatomic landmarks guided needle placement.

"It remains for proponents of imaging guided injections to demonstrate that employing this approach does more than improve short term outcomes, but makes a real difference over the longer term sufficient to justify the extra cost," the authors wrote. "Until such data are available, it seems reasonable to conclude that while some joints such as the hip and midtarsal joints demand imaging for any accuracy of steroid placement…imaging guided injection should be reserved for those cases who have not responded to injection following anatomical landmarks."

Reference

Hall S, Buchbinder R. Do imaging methods that guide needle placement improve outcome? Editorial. Ann Rheum Dis. 2004;63:1007-1008.