Association of Clinical Assessments of Hand Function and Quantitative Ultrasound Metrics in First Carpometacarpal Osteoarthritis.

Abstract

Thumb carpometacarpal (CMC) osteoarthritis (OA), a degenerative condition affecting hand use, is typically evaluated through radiographs and clinical examination. Although this can determine treatment, it is difficult to evaluate functional limitations. Shear wave elastography (SWE) is a quantitative ultrasound technique that characterizes tissue stiffness. This pilot study aimed to establish data of the SWE findings in the thenar eminence muscles in patients with first CMC OA and correlate these findings with the clinical tests of hand function. This cross-sectional study correlated the SWE stiffness of thenar eminence muscles to clinical tests of hand function in patients with first CMC OA and in asymptomatic control subjects, using Spearman's correlation coefficient. Mean SWE values of the thenar eminence muscles in patients were compared with those in control subjects. The study was performed in a non-profit tertiary care hospital setting. Patients and control subjects were recruited on a volunteer basis. SWE values in the abductor pollicis brevis and flexor pollicis brevis muscles showed moderate to very strong correlation with multiple measures of hand function. Mean SWE values of the thenar eminence muscles in first CMC OA patients were lower than those in asymptomatic control subjects. Correlations between mean SWE values in the thenar eminence muscles and clinical measures of hand function suggest decreased function in subjects with less stiff thenar eminence muscles.