Clinical and radiographic distribution of structural damage in erosive and nonerosive hand osteoarthritis

Objective To characterize the clinical and radiographic joint phenotype in erosive hand osteoarthritis (EHOA) and non-EHOA. Methods A total of 446 patients with HOA (233 with EHOA and 213 with non-EHOA) were evaluated. Demographic (sex and age at disease onset), clinical (body mass index and distribution of nodes), and radiographic features (Kellgren/Lawrence and Kallman's scores obtained from radiographs of both hands) from all patients were recorded. Results Patients with EHOA had a significantly earlier disease onset. Clinical and radiographic distribution of structural damage in the distal interphalangeal (DIP), proximal interphalangeal (PIP), and first carpometacarpal joints was similar in EHOA and non-EHOA. EHOA patients showed higher percentages of nodes and more severe radiographic scores; the more severe radiographic score of joints with nodes was due to both osteophytes and joint space narrowing (JSN). A direct correlation between osteophytes and JSN scores was observed. Central erosions (CE) were more prevalent in the DIP joints than in the PIP joints. Gull-wing pattern of CE was prevalent in the DIP joints, whereas saw-tooth pattern was prevalent in the PIP joints. Marginal erosions (ME) were present in 100% of EHOA patients and in 80% of non-EHOA patients. An ordinal correlation between the presence of ME and osteophyte score was found. Conclusion We found quantitative, but not topographic, differences in structural damage between EHOA and non-EHOA. Heberden's nodes, severe radiologic scores, and CE were concentrated in the second, third, and fifth DIP joints of both hands. ME were also present in the majority of non-EHOA patients.