Diagnostic utility of strain elastography in assessing median nerve changes among rheumatoid arthritis patients without symptoms of carpal tunnel syndrome: An analytical observational study

Abstract

Background: The elastography measurements in rheumatoid arthritis (RA) without carpal tunnel syndrome (CTS) are the least studied. Hence, the present study assessed the role of elastography in detecting the median nerve changes before the development of CTS in subjects with RA. Methodology: A prospective observational study was conducted from January 2020 to July 2021 among 112 patients with and without RA. They were divided into Group A cases and Group B controls of 56 each. The patients underwent ultrasonography and strain elastography. Changes in median nerve stiffness were the primary outcome variable. P < 0.05 was considered significant and was analyzed using CoGuide software. Results: The mean age of the patients was 48.5 ± 13.31 years, and most of them were females (64.29%) in both groups. The cross-sectional area (CSA) of median nerve at carpal tunnel inlet in cases and controls was 0.110 (0.105–0.116 cm2) and 0.090 (0.083–0.095 cm2) in right hands, respectively, and 0.109 (0.104–0.116 cm2) and 0.089 (0.082–0.093 cm2) in left hands, respectively. The mean strain ratio (SR) of the median nerve in cases and controls was 2.84 (2.41–2.98) and 1.65 (1.41–1.94) in right hands, respectively, and 2.76 (2.45–3.04) and 1.66 (1.43–1.93) in left hands, respectively. The difference in means of CSA and SR was significant across the groups (P < 0.001). Conclusion: The use of elastography in evaluating the median nerve changes in RA subjects without CTS was useful as changes in the CSA and SR were significant in cases compared to controls.

Keywords

• carpal tunnel syndrome
• elastography
• median nerve
• rheumatoid arthritis
• strain ratio