Development of pathological lumbar kyphosis in myelomeningocele.

We analysed the cases of lumbar kyphosis in 151 (21%) of a series of 719 patients with myelomeningocele. Three different types were distinguished: paralytic, sharp-angled and congenital. In a cross-sectional and partly longitudinal study the size and magnitude of the kyphosis, the apex of the curve and the level of paralysis of each group were recorded and statistically analysed. Paralytic kyphosis (less than 90 degrees at birth) occurred in 44.4% and increased linearly during further development. Sharp-angled kyphosis (90 degrees or more at birth) was present in 38.4% and also showed a linear progression. In both types, progression seemed to depend also on the level of paralysis. Congenital kyphosis occurred in 13.9% and we could find no significant factor which correlated with progression.