The Dorsal 4-Finger Technique: A New Method to Examine Joints in Rheumatoid Arthritis

The dorsal 4-finger technique (DFFT) is a new and reliable method for examining metacarpophalangeal (MCP) joints in patients with rheumatoid arthritis (RA) and is better correlated with ultrasound than the traditional 2-finger technique (TFT), according to a study published in The Journal of Rheumatology.¹

Joint counts are key in measuring outcomes in RA, and imaging techniques such as ultrasound and magnetic resonance imaging are more sensitive in detecting synovial than clinical examination.^2-7 However, there are limitations in using ultrasound in daily clinical practice⁸; therefore, a novel 4-finger technique of joint examination was developed to improve the detection of swelling in the MCP.¹

To validate this novel clinical examination technique, 4 rheumatologists evaluated 180 MCP joints in 18 patients with RA, using either the TFT or the DFFT, and all patients underwent US examination for greyscale (GSUS) and PDUS by a certified musculoskeletal radiologist.

The researchers found that the mean intraobserver agreement using the DFFT was 80.5% and 86% for the TFT, and the mean interobserver agreements were 84% and 74%, respectively.

Agreement with ultrasound findings was similar for both techniques in tender joints, but was higher for the DFFT in nontender joints, suggesting that in the absence of tenderness, the DFFT might give a more accurate assessment of disease activity. In addition, the DFFT had a higher sensitivity in detecting ballottement by GSUS (P <.001) and PDUS (P <.001).

“The DFFT is a novel physical examination technique for detecting MCP joint swelling characterized by ballotability that is more sensitive than the standard TFT detection technique, and it correlates better with [ultrasound] findings,” concluded the authors.¹

This improved sensitive technique for detecting joint swelling with better ultrasound correlation will provide more clinically relevant information on which clinicians can base their treatment decisions.

References

1. Omair MA, Akhavan P, Naraghi A, et al. The dorsal 4-finger technique: a novel method to examine metacarpophalangeal joints in patients with rheumatoid arthritis. J Rheumatol. 2018;45(3):329-334.
2. Brown AK, Quinn MA, Karim Z, et al. Presence of significant synovitis in rheumatoid arthritis patients with disease-modifying antirheumatic drug-induced clinical remission: evidence from an imaging study may explain structural progression. Arthritis Rheum 2006;54:3761-3773.
3. Szkudlarek M, Klarlund M, Narvestad E, et al. Ultrasonography of the metacarpophalangeal and proximal interphalangeal joints in rheumatoid arthritis: a comparison with magnetic resonance imaging, conventional radiography and clinical examination. Arthritis Res Ther 2006;8:R52.
4. Szkudlarek M, Court-Payen M, Jacobsen S, Klarlund M, Thomsen HS, Ostergaard M. Interobserver agreement in ultrasonography of the finger and toe joints in rheumatoid arthritis. Arthritis Rheum 2003;48:955-962.
5. Rees JD, Pilcher J, Heron C, Kiely PD. A comparison of clinical vs ultrasound determined synovitis in rheumatoid arthritis utilizing gray-scale, power Doppler and the intravenous microbubble contrast agent ‘Sono-Vue’. Rheumatology 2007;46:454-459.
6. Naredo E, Bonilla G, Gamero F, Uson J, Carmona L, Laffon A. Assessment of inflammatory activity in rheumatoid arthritis: a comparative study of clinical evaluation with grey scale and power Doppler ultrasonography. Ann Rheum Dis 2005;64:375-381.
7. Tokai N, Ogasawara M, Gorai M, Matsuki Y, Yamada Y, Murayama G, et al. Predictive value of bone destruction and duration of clinical remission for subclinical synovitis in rheumatoid arthritis patients. Mod Rheumatol 2015;25:540-545.
8. Delle Sedie A, Riente L, Bombardieri S. Limits and perspectives of ultrasound in the diagnosis and management of rheumatic diseases. Mod Rheumatol 2008;18:125-131.