FEET AND ANKLES.

The MTP joints are the most commonly involved sites. Subluxation of the metatarsal heads into the soles, often with cock-up and valgus deformities of the toes, results in painful walking and difficulty with footwear. Ankle and/or tarsal collapse may result in painful valgus deformity and/or pes planus.

NECK.

Neck pain and stiffness are common. As in other joints, the rheumatoid process can lead to erosion of bone and ligaments in the cervical spine. Atlantoaxial subluxation (C1 on C2) can be seen radiographically in up to 30% of cases (Fig. 286-7) . Spinal cord compression with neurologic manifestations occurs infrequently ，but is a neurosurgical emergency. Occipital and/or frontal headache is a common premonitory sign of weakness in the extremities, bladder or bowel incontinence, or frank quadriplegia. Vertebral arteries may also be compressed and lead to vertebrobasilar insufficiency with vertigo or syncope, especially on downward gaze. Head tilt may occur from lateral mass collapse of the C1 and C2 vertebrae.

ELBOWS.

Proliferative synovitis in the elbow often causes flexion contractures, even early in the disease. Supination of the hand may be impaired, especially if shoulder motion is concomitantly decreased. Rarely, ulnar or radial nerves may become entrapped.

SHOULDERS.

Involvement of the glenohumeral, acromioclavicular, and thoracoscapular joints is common in advanced but not early RA. Limited motion and tenderness just below and lateral to the coracoid process are typical symptoms. Noticeable swelling is rare; however, large synovial cysts may occur (see Color Plate 3 D). Joint destruction usually involves rupture of the joint capsule and subluxation of the humerus.

HIPS.

Pain in the groin, lateral aspect of the buttock, or lower part of the back may indicate hip involvement. Because the hip joint capsule has poor distensibility, severe pain can result if a large effusion occurs. Arthrocentesis should be done to relieve pain and exclude infection in such cases. Rarely, extreme hip destruction results in protrusion of the femur into the pelvis.

CRICOARYTENOID JOINTS.

Synovitis of the cricoarytenoid joints may result in dysphagia, hoarseness, or anterior neck pain. The sudden onset of stridor and dyspnea in a patient with RA is an emergency. Prompt administration of intra-articular or parenteral corticosteroids and/or tracheostomy may be necessary.

EXTRA-ARTICULAR MANIFESTATIONS.

Constitutional symptoms, including malaise, fatigue, weakness, low-grade fever, and mild lymphadenopathy, are common in RA. All the extra-articular complications occur almost exclusively in seropositive patients.

SKIN.

Subcutaneous nodules occur in 20 to 25% of RA patients and are almost always associated with serum rheumatoid factor and more severe articular disease. They occur most commonly in periarticular structures and areas subject to pressure, such as the elbows, extensor and flexor tendons of the hands and feet, Achilles tendons, and less commonly, the occipital and sacral areas. They may occasionally become infected but are usually asymptomatic.

Palmar erythema and fragility of the skin resulting in easy bruising are common manifestations. Rheumatoid vasculitis occurs in two major forms. The 1st is manifested by small, splinter-shaped brown infarcts in the nail folds and digital pulp, often also present over subcutaneous nodules (see Color Plate 3 E). Histologic examination may reveal leukocytoclastic vasculitis or a mild venulitis. This process is benign in most patients and does not indicate serious systemic vasculitis. The 2nd form is a severe necrotizing vasculitis of small and medium arteries indistinguishable from periarteritis nodosa. Digital infarcts, mononeuritis multiplex, fever, and other manifestations of systemic disease should prompt aggressive therapy.