Cortical bone measurements in Turner's syndrome.

Cortical bone width measurements taken at midshaft on the second metacarpal were obtained from 156 hand X-rays of 80 karyotypically documented individuals with Turner's syndrome age 1 to 25 years. Total shaft width, medullary width, cortical width and percent cortical area were grouped by bone age and compared with normal female standards. Total width was significantly and increasingly below normal; medullary width was not consistently different from normal; cortical width was significantly lower from normal from age 14 onward, although it did rise at age 17 (adult bone age); percent cortical area was significantly below normal at ages 14 and 15, but was normal by adulthood. Values for percent cortical area did not indicate severe or widespread osteoporosis. Within the Turners sample cortical bone measurement were not significantly decreased in the presence of the XO sex chromosome constitution compared with other sex chromosome variants. Nor were the measurements decreased in the presence of positive metacarpal sign or a combination of typical Turner stigmata (web neck, low posterior hairline, shield chest). There was evidence that cortical width and percent cortical area increased significantly following estrogen treatment or spontaneous menarche.