Fusion of interphalangeal joints

Symphalangism is a rare congenital anomaly characterized by ankylosis of interphalangeal joints of fingers and toes. {1} This autosomal dominant disorder was first described by Harvey Cushing in 1916. {2} Recent studies have revealed that the abnormal genes are localized on chromosome 17q22. {3} The fusion can occur in any finger. Little finger is most frequently involved, followed by ring, middle and index finger. {1} Index finger is generally involved only when other fingers are also involved. Involvement of both proximal and distal interphalangeal joints can occur, but proximal interphalangeal joint involvement is more common. {1} It may be associated with Poland, Apert, Herrmann, and multiple synostosis syndromes. {1,3} The treatment of symphalangism has been uniformly unsuccessful. Manipulations and arthroplasties can be applied and physical, occupational, and exercise therapies are usually beneficial. {3}

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References :

Borah D, Wadhwa S, Singh U, Gupta AK. Symphalangism in an Indian family. Ind J Phys Med Rehabil. 2006; 17: 18–20 Cushing H. Hereditary anchylosis of proximal phalangeal joints (symphalangism). Genetics. 1919; 1: 90–106. Durmus O, Cakar E, Ata E, Dincer U, Kiralp MZ. Symphalangism: ankylosis of the interphalangeal joints. Am J Phys Med Rehabil. 2014;93:90-91