Development and assessment of inter- and intra-rater reliability of a novel ultrasound tool for scoring tendon and sheath disease – A pilot study

Abstract

Tendon and synovial sheath disease is common. A method of monitoring the status of tendons and sheaths is important for both diagnosis of pathology and evaluation of the efficacy of treatments. For this study, an ultrasound scoring tool was developed and its reliability tested between raters. The tool is novel in that it scores tendons and sheaths separately, an important consideration since disorders of these structures are not necessarily concurrent. Thirty diseased tendons and sheaths were included in this pilot cross-sectional study. Tendon and sheath measurements were taken and the semi-quantitative five-grade score was applied to assess tendon greyscale, tendon Doppler activity and sheath Doppler activity. Inter-rater and intra-rater agreement exercises were undertaken to test the reliability of the scoring tool. The Intra-class Correlation Coefficient values for both the inter-rater and intra-rater reliability tests showed excellent agreement for the tendon and sheath measurements. Unweighted kappa estimations for inter-rater scores showed excellent agreement for tendon Doppler; good agreement was shown for scoring sheath Doppler, while poor agreement was shown for tendon grey-scale scoring. The intra-rater reliability scores demonstrated similar results. Overall, the study strongly supports the use of this scoring tool for the diagnosis and follow-up of tendon and sheath disorders. The results may be used as a starting point from which to base further work in this important area. Future studies should address the limitations found in this research with a strong focus on improving tendon grey-scale measurement accuracy and agreement.