NEUROPATHIC JOINT DISEASE (Charcot Joints)

This chronic progressive degenerative arthropathy can be a complication of a variety of neurologic disorders. Impairment of proprioceptive and pain sensations deprives the affected joint of the normal protective reactions that ordinarily modulate the forces of weight bearing and motion. Diabetic neuropathy is now the most common and syphilitic tabes dorsalis the second most common cause of this joint disorder. Syringomyelia, myelomeningocele, and congenital indifference to pain are less frequent causes of neuropathic arthropathy. The basic neurologic lesion determines the distribution of the affected joints. In tabes dorsalis, the knees, hips, ankles, and vertebrae are frequently involved. In diabetic neuropathy, the changes are limited to the distal lower extremities, and in syringomyelia the shoulder and elbow joints are most commonly affected.

Although pain is generally present, discomfort tends to be mild relative to the degree of joint destruction. Clinical, pathologic, and roentgenographic features of chronic neuropathic joint disease reflect severe degrees of destruction and disorganization of the involved joints. Synovial fluid is usually noninflammatory, but it can be hemorrhagic and contain destructive debris (fragments of cartilage or bone). In the early stages, differentiation from other causes of joint derangement depends upon demonstration of a sensory neuropathy.

Management includes immobilization of affected joints and restriction of weight-bearing activities with crutches, splints, and braces. Surgical arthrodesis, although frequently unsuccessful, is indicated in selected individuals. Total joint replacement has been attempted, but success has been limited and most consider this approach contraindicated.

HEMARTHROSIS

Recurrent or chronic hemarthrosis is the most common complication of a group of heritable disorders of blood coagulation (see Ch. 167). Hemarthrosis can be a complication of anticoagulant therapy or severe trauma to a normal joint. In hemophilia, joint bleeding usually begins before the age of five and tends to recur repeatedly during childhood in response to even minor injury. The most common sites are the knees, elbows, and ankles, but any joint can be involved.

Acute hemarthrosis usually results in marked local inflammation and joint symptoms that can last for days to weeks. Approximately one half of patients with hemophilia develop chronic deformities in one or more joints. Some of them develop a chronic progressive synovitis, restricted to one or a few joints, which clinically and roentgenographically resembles rheumatoid arthritis. In chronic cases there is marked synovial membrane hyperplasia, destruction of articular cartilage, and erosions of subchondral bone. This chronic pro- gressive pattern probably results from a low level of continuous or intermittent bleeding into involved joints. joint fluid, in chronic cases, usually contains blood and very high levels of leukocyte-derived proteases. Other musculoskeletal manifestations of hemophilia include bleeding into muscle and bone * The resolution of large hematomas can produce chronic cysts within these tissues.

The first principle in management is to prevent trauma, a goal not easily achieved in children. Acute hemarthrosis should be managed by immobilization, analgesic therapy, and the administration of appropriate plasma concentrates that contain the required coagulation factor. Aspirin and other nonsteroidal analgesics that alter platelet function should be avoided. If there is marked distention of a joint or bursa, aspiration can be accomplished after the defect in coagulation has been corrected. When pain and acute inflammation have subsided, an exercise program to restore range of joint motion should be initiated. For the patient with severe chronic deforming joint disease, the availability of potent plasma concentrates has made it possible to perform synovectomy and arthroplasty in selected instances.

HENOCH-SCHONLEIN PURPURA

Polyarthralgia and a nondeforming arthritis, most frequently affecting knees and ankles, are common manifestations of this disorder. Other features include nonthrombocytopenic purpura, abdominal pain, and glornerulonephritis. The syndrome is rare in adults.

This rare disorder usually begins in the middle decades of life and affects females three times more frequently than males. It is characterized by the development of multiple histiocytic nodules in the skin and severe polyarthritis that may simulate rheumatoid arthritis. The firm reddish-brown or yellow papular nodules are most commonly found on hands, forearms, head, neck, and chest. Mutilating joint destruction, especially in the interphalangeal joints, occurs in approximately one half of patients with this syndrome. Diagnosis is made by demonstration of histiocytes and multinucleated giant cells containing PAS-positive material in skin or synovium. Similar infiltrates have been observed in other organs. Reports of apparent benefit from adrenocorticosteroid or immunosuppressive therapy are difficult to interpret because of the tendency for spontaneous remission in this disorder

HYPERTROPHIC OSTEOARTHROPATHY

This term refers to a syndrome that includes clubbing of fingers and toes, periostitis at the ends of long bones, arthritis, and in some cases signs of autonomic dysfunction such as flushing, blanching, and profuse sweating of the extremities. The syndrome occurs with a wide variety of underlying disease states. There is a rare hereditary and idiopathic form (pachydermoperiostosis) of this disorder. The fully expressed pattern is usually associated with intrathoracic disease: lung carcinoma, lung abscess, emphysema, bronchiectasis, chronic interstitial pneumonitis, or mesothelioma. Clubbing, usually without periostitis, can be seen with cyanotic heart disease, cystic fibrosis, bacterial endocarditis, biliary cirrhosis, ulcerative colitis, regional enteritis, or thyroid disease.

The distal joints (wrist, elbows, ankles) and long bones of the forearms and legs are most frequently affected. There are inflammatory changes in the periosteum, synovial membrane, and periarticular structures. The periosteum is "lifted" by the deposition of new bone matrix and subsequent mineralization. Clubbing results from edema, cellular infiltration, and connective tissue proliferation in the nailbeds

Pain, tenderness, and enlargement of the distal portions of extremities may be accompanied by an acute polyarthritis that superficially resembles rheumatoid arthritis. Correct diagnosis of the acute polyarthritis syndrome is established by the recognition of digital clubbing and roentgenographic evidence of periostitis and intrathoracic disease.

The production of a humoral substance that mediates increased vascularity or connective tissue proliferation or both has long been suspected as the pathogenic factor in hypertrophic osteoarthropathy, but no such factor has been demonstrated. Evidence that neural factors are involved is derived from observations of striking resolution of signs and symptoms after denervation of the hilum or vagotomy on the same side as the thoracic lesion. Regression of osteoarthropathy has also been observed after resection of pulmonary neoplasms.

Aside from therapy directed at the associated disease, there is no effective treatment for hypertrophic osteoarthropathy. Symptomatic benefit may be obtained from salicylates, other analgesics, or adrenocorticosteroids.

PALINDROMIC RHEUMATISM AND INTERMITTENT HYDRARTHROSIS

These terms describe two different constellations of clinical findings in which no pathogenic mechanism or mechanisms have been defined and in which the symptoms are often the prodrome of another rheumatic disease. Palindromic rheumatism is a term applied to a recurrent pattern of polyarthritis that in individual cases is quite constant. The episodes are usually of brief duration. Many patients eventually develop typical features of rheumatoid arthritis. Intermittent hydrarthrosis is typified by recurrent joint effusions, usually occurring in young females at menstruation and involving the knee. Like palindromic rheumatism, there is a strong tendency for cases to evolve into rheumatoid arthritis. Diagnostic arthrocentesis is justified in each condition based upon the local joint findings during an acute attack. Since each of the disorders remits spontaneously for variable periods of time, there is no uniform opinion regarding treatment, which is strictly symptomatic.