Musculoskeletal ImagingHyperthyroidism
a disorder caused by excess amounts of
thyroid hormones, leading to
thyrotoxicosis. Distinctive bone, joint and soft tissue alterations may accompany hyperthyroid states, emphasizing the importance of
thyroid hormone in regulating normal growth, development and maturation of tissue. Among the many forms of
thyrotoxicosis are toxic
diffuse goitre (
Graves disease), also called Basedow's disease and toxic
nodular goitre, produced by single or multiple adenomas. Patients may have fatigue, weakness, nervousness, hypersensitivity to heat, hyperhidrosis, weight loss, tachycardia, palpitation, eye complaints, diarrhoea, enlargement of the neck, tremor,
thyroid bruit, and musculoskeletal abnormalities.
Excessive bone turnover with a negative calcium balance leads to resorption, pain, fracture, reduction in height and exaggerated dorsal kyphosis. In hyperthyroidism, both bone resorption and bone formation are increased, but resorption is more dominant. Spontaneous fractures in hyperthyroidism involve vertebrae, the femoral neck, other long bones and even the metacarpals. The radiographic features of bone loss in hyperthyroidism are those of osteoporosis in general, although the pelvis, cranium, hands and feet may show alterations in addition to the vertebral column. In the skull, the radiographic findings resemble those of multiple myeloma. Children may show acceleration of skeletal maturation and premature craniosynostosis. Myopathy is also frequent in hyperthyroidism; weakness, cramps and muscular tenderness are observed. The neurologic findings in hyperthyroidism include peripheral neuropathy, corticospinal tract disease, chorea, seizures and psychiatric disorders.
Thyroid acropachy is an unusual manifestation of thyroid disease typically observed after treatment of hyperthyroidism. Features of this condition include painless soft tissue swelling of the fingers and toes with underlying periostitis, pretibial myxoedema and clubbing of the fingers.
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