EARLY AND MODERATE HAND INVOLVEMENT

The joints of the hands and wrists are among the most frequent sites of involvement (see Plate 5-2). In the fingers, some or all of the proximal interphalangeal joints are often bilaterally affected whereas the distal interphalangeal joints are seldom involved. Because the inflammatory swelling occurs only at the middle joints, the affected fingers become fusiform in the early stages of disease. The metacarpophalangeal and wrist joints may also become inflamed. At first, there is little restriction of motion in the involved joints, but stiffness, swelling, and pain prevent the patient from making a tight fist, thus weakening grip strength. Except for soft tissue swelling, radiographs reveal no abnormalities.

ADVANCED HAND INVOLVEMENT

As the disease progresses and the inflammation invades the joints, destroying articular cartilage and bone, joint motion becomes severely limited and joint deformities develop (see Plate 5-3). Flexion deformities frequently occur at the proximal interphalangeal and metacarpophalangeal joints. The patient cannot fully extend or flex the fingers, and the grip becomes progressively weaker. Radiographs reveal cartilage thinning, manifest as joint space narrowing, bone erosions at the joint margins, and metaphyseal (periarticular) osteoporosis. After years of chronic inflammation, joint damage becomes severe; the joint capsule stretches; muscles atrophy and weaken; and tendons stretch, fray, and even rupture. All of these changes result in severe, incapacitating deformities.