Assessment of phalangeal bone loss in patients with rheumatoid arthritis by quantitative ultrasound

Objective-Periarticular osteopenia is an early radiological sign of rheumat oid arthritis (RA). Quantitative ultrasound (QUS) devices have recently bee n shown to be useful for assessing osteoporosis. In this study the capabili ty of a transportable and easy to use QUS device to detect skeletal impairm ent of the finger phalanges in patients with RA was investigated. Methods-In a cross sectional study 83 women (30 controls, 29 with glucocort icosteroid (GC) treated RA, and 24 with GC treated vasculitis) were examine d. QUS measurements were obtained at the metaphyses of the proximal phalang es II-V and directly at the proximal interphalangeal joints II-IV with a DB M Sonic 1200 (IGEA, Italy) QUS device. Amplitude dependent speed of sound ( AD-SoS) was evaluated. In 23 of the patients with RA, hand radiographs were evaluated. Results-Significant differences between patients with RA and the other grou ps were found for AD-SoS at both measurement sites. Compared with age match ed controls, the AD-SoS of patients with RA was lowered by two and three st andard deviations at the metaphysis and joint, respectively. Fingers of pat ients with RA without erosions (Larsen score 0-I) already had significantly decreased QUS values, which deteriorated further with the development of e rosions (Larsen II-V). Conclusion-This study indicates that QUS is sensitive to phalangeal periart icular bone loss in RA. QUS is a quick, simple, and inexpensive method free of ionising radiation that appears to be suited to detection of early stag es of periarticular bone loss. Its clinical use in the assessment of early RA should be further evaluated in prospective studies.