Developmental malformations in the area of the lumbosacral transitional vertebrae and sacrum: differences in gender...

The aim of this study was to determine the incidence of congenital malformations of the lumbosacral transitional vertebrae in the general population, and the differences in their gender and left/right distributions.

The examined group comprised of all patients who underwent a pelvic X-ray during 2010 for any reason. The observed parameters included the following malformations: the presence of megatransversus at L5; sacralization of L5 or L6; a S1 lumbarization; the presence of six sacral vertebrae; or spina bifida at the level of L5, S1 or S2. In cases of megatransversus at L5, the lateral distribution was recorded. A total of 1,513 images were evaluated. Sex and lateral differences were evaluated using the Pearson's (χ (2)) test with a significance level of 5 %.

A total of 478 malformations were found in 417 patients, which constituted 27.6 % of the entire group. Malformations occurred in 250 women (25.4 % of all women) and 167 men (31.6 % of all men) and the female to male ratio in affected individuals was 1.5:1. The predominance of the occurrence of malformations observed in men was statistically significant (p = 0.009). The most frequently occurring malformations were the presence of six sacral vertebrae (179 patients) and megatransversus at L5 (150 patients). The study confirmed a high incidence of congenital malformations in the area of the lumbosacral transitional vertebrae and demonstrated a higher incidence in males. Unilaterally occurring megatransversus at L5 was significantly more common on the left side.