PROGRESSION OF DIGITAL OSTEOARTHRITIS - A SEQUENTIAL SCINTIGRAPHIC AND RADIOGRAPHIC STUDY

Hand radiographs and scintigraphy were obtained initially and at the 4 -year follow-up in 15 patients with symptomatic osteoarthritis (OA) of distal and/or proximal interphalangeal joints. For each joint, a 0-15 score was obtained for the OA radiographic lesions read blind by the same observer. An abnormal isotope retention over a bone reference are a was assessed and quantified. The predictive value of scintigraphy fo r the OA radiographic progression was confirmed and shown to be improv ed by a second investigation. During the study period, the percentage of radiographic OA joints increased from 66.3 to 76.6%, but joints sho wing an abnormal scan decreased from 40 to 22.5%. Progression of the O A radiographic score was closely related to scintigraphic changes. The mean difference between the final and initial OA score was -0.08 in j oints with two normal scans (N=115), +0.73 in joints showing a first a bnormal and a second normal scan (N=94) and +1.8 in joints with two ab normal scans (N=14) or a scan becoming abnormal (N=47). An abnormal sc an appears to represent a transient event, and this event is associate d with a period of progression of digital OA. Potentially, anti-GA the rapies that suppress joint isotope retention might slow down OA progre ssion. The magnitude of joint isotope retention was positively correla ted with the OA radiographic score established at the same time (R=0.6 1 and P <0.001), but showed no predictive value for progression of the latter.