Radiographic hand osteoarthritis: patterns and associations with hand pain and function in a community-dwelling...

Area of Science:

• Rheumatology
• Orthopedics
• Epidemiology

Background:

• Radiographic osteoarthritis (ROA) of the hand is common, but patterns, especially involving thumb joints, are inconsistently studied.
• Understanding ROA patterns is crucial for defining subgroups and their impact on patient outcomes.

Purpose of the Study:

• To determine relationships of ROA at different hand joints.
• To define radiographic subgroups of hand OA based on these patterns.
• To investigate associations between these subgroups and pain/function.

Main Methods:

• Principal components analysis (PCA) was used to analyze ROA patterns in 16 hand joints from 592 adults aged 50+ with hand pain.
• Participants were categorized into four radiographic subgroups: no OA, finger only OA, thumb only OA, and combined thumb and finger OA.
• Pain and function were assessed using the Australian/Canadian Osteoarthritis Index (AUSCAN), Grip Ability Test (GAT), and grip/pinch strength.

Main Results:

• PCA identified four main components of ROA: DIPs, PIPs, MCPs, and thumb joints.
• Four distinct radiographic subgroups of hand OA were defined.
• Statistically significant differences in AUSCAN function and grip/pinch strength (in women) were observed between subgroups, with combined thumb and finger OA exhibiting the worst outcomes.

Conclusions:

• Individual thumb joints can be effectively grouped together when analyzing ROA.
• Four distinct radiographic subgroups of hand OA can be identified.
• Combined thumb and finger OA is associated with the highest levels of pain and functional impairment.