Certain abnormalities, particularly those in the hands, may suggest a specific disorder: (bony overgrowths at the distal interphalangeal joints) or (bony overgrowths at the proximal interphalangeal joints): Osteoarthritis Subluxation of the metacarpophalangeal joints with ulnar deviation of the fingers: Chronic rheumatoid arthritis (hyperextension of the proximal interphalangeal joint with flexion of the distal interphalangeal joint) and (hyperextension of the distal interphalangeal joint with flexion of the proximal interphalangeal joint): Rheumatoid arthritis These deformities may interfere with functioning or usual activities.