Relationship of sacral articular surfaces and gender with occurrence of lumbosacral transitional vertebrae

Background context: Research on lumbosacral transitional vertebra (LSTV) has yielded important information on the structural alterations of the sacrum associated with LSTV. Nevertheless, very little data are available on the relationship of a given type of LSTV with either a typical pattern of sacral morphology or its gender distribution in the population.

Purpose: To investigate the probable relationship between different variants of LSTVs with sacral morphology at the articular surfaces of the bone and the gender distribution of the anomalies in the population.

Study design: Cross-sectional descriptive study involving dried human sacral bones and meta-analysis of data available related to LSTVs.

Methods: Three hundred twenty sacra were screened for the presence of LSTV, the type of auricular surface, and facet joints in them. Samples were grouped against their sexes, type of the auricular surfaces present in them, the nature of facet joints, and the variety of LSTV (if present). Data on LSTV from reliable Internet databases were collected to account for the prevalence of LSTV in the population in terms of the types of the anomaly and their gender distribution.

Results: The detection rates of LSTV in the present study were similar to those observed in available literature. Accessory L5-S1 articulations and lumbarization of S1 were more commonly observed in the women. Sacralization was seen to be predominantly distributed in men. Higher auricular surfaces were associated with accessory articulations; lower auricular surfaces were present with partially separated S1 segment and in L5-S1 specimens. Morphology of the facets significantly altered in LSTV with accessory articulations.

Conclusions: Different lumbosacral transitions share a stronger, definite, and specific patterns of relationship with certain sacral morphologies and gender. It is important to recognize the nuances of these connections so as to understand low back pain conditions in the setting of a typical sacral articular morphology or the sex of the individual.