Correlation between FIHOA and AUSCAN and radiographic damage in patients with osteoarthritis of the hands

Abstract

Objective: To explore the relationship between functionality, assessed by FIHOA and AUSCAN, and radiographic damage. Methods: Seventy persons with osteoarthritis (OA) of the hands completed the AUSCAN and FIHOA. All interphalangeal (IP)(n = 1260) and metacarpal joints (MCP)(n = 700) were characterized as being in the normal (N), stationary (S), loss of joint space (J), erosive (E), remodeled (R) or fused (F) anatomical phase, with a corresponding numerical score. A total score was attributed to each patient for both hands (all IP + MCP) and the dominant hand separately. Besides, separate scores were calculated per hand for the distal IP (DIP), proximal IP (PIP), all IP (PIP + DIP), and MCP joints. The thumb base joints (scapho-trapezial (TS) (n = 140) and trapezio-metacarpal (TMC) (n = 140)) are scored based on the OAC radiographic atlas for OA of the hand. Spearman’s rho correlations were calculated between radiographic scores and functional scores. Results: Correlations between radiographic scores and functionality (FIHOA and AUSCAN) were calculated (table 1). A difference in approaching functionality by either AUSCAN or FIHOA is observed. Correlation between radiographic score and functionality assessed by FIHOA is better than by AUSCAN (r = 0.405 and 0.310), for the total radiographic score, and r = 0.454 vs. 0.361 for the dominant radiographic score). Moreover, the correlation between functional impairment and radiographic score of the dominant hand is slightly better than the total score (both hands). Presence of affected IP joints, especially PIP joints, seems to contribute most to functional impairment (i.e. more than affected MCP and CMC joints). The correlation between functionality and radiographic score of the CMC joints is poor. The correlation between pain or stiffness and the radiographic score is low. Conclusion: The FIHOA seems to correlate better with structural damage than the AUSCAN. The contribution to functional impairment is the largest from affected PIP joints