Symphalangism

Symphalangism is a rare congenital disorder characterized by the fusion of two or more bones within a digit. Most commonly, it affects the toes, specifically the fusion of the proximal and middle phalanges of the second to fifth toes, leading to a stiff, shortened toe. This fusion can also occur in the fingers, though it is less frequent.

The condition can be inherited in an autosomal dominant pattern, meaning only one copy of the altered gene is needed for a person to be affected. However, it can also arise spontaneously without a family history. Symphalangism is often associated with other skeletal abnormalities and syndromes, such as syndactyly (webbing of fingers or toes) and brachydactyly (shortening of digits).

Diagnosis is typically made through physical examination and can be confirmed with X-rays, which clearly show the fused bones. There is no cure for symphalangism, and treatment focuses on managing symptoms and improving function. In cases where the fused digits cause pain, difficulty with footwear, or functional impairment, surgical intervention may be considered. Surgical options can include osteotomy (cutting the bone) to separate the fused segments or amputation in severe cases. The prognosis varies depending on the severity of the fusion and the presence of associated conditions.