SPONDYLOEPIPHYSIAL DYSPLASIA TARDA. HEREDITARY CHONDRODYSPLASIA WITH CHARACTERISTIC VERTEBRAL CONFIGURATION IN THE ADULT.

Abstract

Spondyloepiphysial dysplasia tarda (SDT) is a distinct, inherited bony dysplasia causing short stature. It occurs only in males and shows characteristic radiologic features in the adult. Failure of normal growth is evident between five and ten years of age. Shortness of stature becomes more noticeable in adolescence and is frequently associated with back pain. Pain in the hip and limitation of motion due to premature osteoarthrosis are common. Some patients, however, deny any symptoms referable to the dysplasia. It is a sex-linked recessive trait so that none of the children of an affected male manifest the condition. Approximately half of his daughters will be carriers of the trait and approximately half of their sons will be affected. The growth insufficiency, which is due to shortening of the entire vertebral column, results in mild dwarfism of the short-trunk type, the recorded height range for adults being from 4 feet 4 inches to 5 feet 2 inches. The structural change in the spine appears to occur for the most part in adolescence, although minimal radiographic changes have been observed as early as five years. Maroteaux, Lamy, and Bernard, in France, first recognized the condition as a distinct entity in 1957 on the basis of their study of three families with twenty affected male members in four generations. They coined the name “la dysplasie spondylo-epiphysaire tardive.” Cases have been reported in brothers by Nilsonne, in Sweden (1927), Volhard and Drigalski (1937) and Hochheim, Körner, and Liebe (1955) in Germany, Halberstaedter (1943) and Barber (1960) in England. Jacobsen, in the United States (1939), described four members of one family in which there were twenty affected individuals in four generations. He believed the condition to be Morquio's disease. Hobaek, in Norway (1960), reported four cases in a family with eleven affected individuals in four generations as examples of chondrodysplasia hereditaria infantilia, general type. Of special interest to radiologists is the distinctive configuration of the vertebral bodies in the lumbar spine in the adult, which permits an unequivocal diagnosis. This consists of generalized flattening of the bodies, with a hump-shaped build-up of eburnated bone in the central and posterior portions of the superior and inferior plates and complete lack of visible bone in the distribution of the ring apophyses (Fig. 1). The disk spaces are narrow. At first glance, the central build-up suggests extensive disk calcification. An element of this may be present anteriorly in the region normally occupied by the ring apophyses, and the vacuum phenomenon in the narrow space between the eburnated humps indicates that premature disk degeneration does occur (Fig. 2).