Patterns and progression in congenital scoliosis

Sixty cases of congenital scoliosis over a 13-year period were studied. The female:male ratio was 1.4:1. The deformity usually presented itself first either at 2 or 8-13 years of age. A positive family history was present in five cases, and parental consanguinity was observed in 40% of patients. Fiv e patterns of deformity were recognized. Hemivertebra was the most common t ype, and unilateral unsegmented bar with contralateral hemivertebra was the most severe and most progressive pattern of deformity. Thoracic curves wer e more prevalent while larger curves were more commonly seen in the thoraco -lumbar area. The curves measured >40 degrees in 70% of the patients who ha d reached maturity. The curve progression index was 9 degrees for unilatera l unsegmented bar with contralateral hemivertebra, and 6 degrees without co ntralateral hemivertebra. This index was 1.5 degrees for hemivertebra and c omplex type of deformity, and 0.5 degrees for block vertebra. Unbalanced fu lly segmented hemivertebra was next after the two types of unsegmented bars in terms of potential for progression. Presence of fused ribs on concave s ide of lower thoracic curves increased the rate of curve progression. Spina l dysraphism, diagnosed in 20% of cases, was the most commonly associated a nomaly.