健康な被験者におけるMCPおよび手関節の皮質骨欠損 HR-pQCTによる評価

Evaluation of bone erosion is important in assessing the progression in rheumatoid arthritis (RA). It is known that cortical bone defects also exist in healthy individuals. We examined erosions occurring in the metacarpophalangeal (MCP) and wrist joints of healthy subjects using high-resolution peripheral quantitative computed tomography (HR-pQCT).

Twenty healthy female subjects were included. The second and third MCP and wrist joints were scanned using HR-pQCT. The number, volume, and anatomical distribution of erosions were measured, and the correlation between erosions number and age was analyzed.

An average of 4.0 erosions were found in the MCP joints, 30.8 in the carpal bones, and 7.9 in the distal radius and ulna. Most erosions (69.3%) were smaller than 0.5 mm3. Larger erosions (>0.5 mm3) were mainly seen in the carpal bones, with an average of 12.1 in total, especially the capitate and lunate (3.9 and 2.2, respectively). The number of carpal erosions correlated with age, especially for erosions smaller than 0.5 mm3 (R = 0.48).

Numerous bone erosions were identified in the MCP and wrist joints of healthy individuals. Relatively well-defined erosions measuring ≥0.5 mm3 were frequently observed in specific carpal bones, particularly the capitate and lunate. Additionally, erosions smaller than 0.5 mm3 showed a positive correlation with age, suggesting that numerous small cortical bone defects may represent age-related physiological changes. These findings provide important context when interpreting erosive changes associated with joint diseases in clinical practice.