Curve patterns and etiologies of scoliosis: analysis in a university hospital clinic in Taiwan.

BACKGROUND: The curvature characteristics and etiologies of scoliosis have been well documented in many countries and among different races but have seldom been reported for Asians. We aimed to determine the etiology frequency and curvature characteristics of scoliotics in Taiwan. MATERIALS AND METHODS: From July 1994 through December 1997, 648 new patients with scoliosis were examined. A whole spine standing radiographic study was taken for each patient. The data were collected prospectively for analysis. RESULTS: Idiopathic scoliosis was the leading type in our series (86%), followed by congenital (6%) and neuromuscular scoliosis (5%). Single thoracic curve was the most common curve pattern (37%), followed by single lumbar (30%), double major (13%), single thoracolumbar (13%), and double thoracic curve (6.6%). The most frequent types of curve were right thoracic (28%) and left lumbar curve (22%), and these were defined as typical curves. The average curve magnitude was smaller in patients with atypical curves (left thoracic or right lumbar) and large curves were not commonly seen. The average curve magnitude increased in patients from the ages of 8 to 12 years and it exceeded Cobb's angle of 20 degrees at the age of 11. CONCLUSION: Idiopathic scoliosis is the most frequent etiology of scoliosis in Taiwan. In our series, idiopathic scoliosis was female predominant (4.3:1), but there were no gender ratio differences in non-idiopathic patients (p < 0.001). Left thoracic curve occurred more often in juvenile idiopathic scoliotics (p = 0.006). Atypical curves were more resistant to curve progression and seldom induced large curves. School scoliosis screening beginning at age 11 is adequate and effective in Taiwan.