Arthritis in Hypothyroidism

This article describes the bone and joint manifestations seen in hypothyroidism, hyperthyroidism, diabetes and hyperparathyroidism.

Hypothyroidism causes a number of different symptoms, including arthropathy and musculoskeletal manifestations ranging from myalgia (muscle inflammation) and arthralgias (bone and joint inflammation) to frank myopathy (muscle disease) and arthritis. Arthropthy is a term similar to arthritis that refers to disease occurring in a joint. The term arthropathy doesn't specify the type of joint disease. People with hypothyroidism tend to develop one or more predominant symptoms rather than all of the symptoms associated with hypothyroidism. In many cases, bone and joint manifestations are the only symptoms of hypothyroidism that occur. This can lead to diagnostic difficulties as doctors look for systemic rheumatic causes and fail to look for endocrine causes of the arthropathy.

OTHER ENDOCRINE CAUSES

Arthropathy and arthritis can occur in several different endocrine disorders, including diabetes, hypothyroidism, hyperthyroidism, and hyperparathyroidism. In diabetes musculoskeletal manifestations are associated with proliferation of fibrous tissue. This causes nerve entrapment and limited joint mobility, especially in the hands, shoulder, hip, palm, and fingers.

Patients with Graves' disease, especially those treated with radioiodine ablation, may develop a condition of acropachy, a condition of soft tissue swelling, finger clubbing, and myopathy.

Hyperparathyroidism is associated with many rheumatic features, including spontaneous fractures, diffuse bone and joint pain, bone cysts, proximal myopathy and peripheral neuropathy. Elevated parathyroid hormone levels may lead to osteoporosis, osteolysis, osteitis fibrosa cystica, and bony erosisons. Crystalline arthropathy, including chondrocalcinosis, pseudogout, and gout are common in primary hyperparathyroidism. Secondary hyperparathyroidism is often associated with calcium phosphate deposits that result in local tissue inflammation.

HYPOTHYROIDISM

In hypothyroidism, excess deposits of the mucopolysaccharide glycosaminoglycan in tissue cause various musculoskeletal symptoms. Although the direct mechanism is unclear, chondrocalcinoisis caused by calcium pyrophosphate dihydrate crystal deposits may be the end result associated with hypothyroidism.

Most cases of hypothyroidism with bone and joint involvement in adults involve the knees and hands. In children with hypothyroidism, the hip and the ephysis of the femoral head are most likely to be affected. Thyroid hormone is necessary for the proper growth and maturation of bone and cartilage at the cellular level.

During periods of growth, the hypothyroid state spears to induce abnormalities in these tissues, which results in aseptic necrosis, crystal-induced arthritis, and an arthropathy characterized by highly viscous non-inflammatory joint effusions primarily affecting the knees, writs, and hands. The nerves and muscles adjacent to these areas may also develop symptoms and appear as joint region abnormalities even when there is no underlying arthropathy.

Autoimmune hypothyroidism, especially the hyperthyroid phase of it, is also associated with a mild, nonerosive, inflammatory oligoarthritis (affecting multiple joints) or polyarthritis that seems independent of thyroid dysfunction and responds well to non-steroidal anti-inflammatory medications.

Resources:

Alan Bridges, Endocrine and Metabolic Arthropathies, Merck Medicus, Best Practice Report, March 27, 2002.

Robert McLean and David Podell, Bone and Joint Manifestations of Hypothyroidism, ScienceDirect, Seminars in Arthritis and Rheumatism, Vol 24(4), Feb 1995.