Differentiation and classification of thoracolumbar transitional vertebrae

Abstract

The literature states that transitional vertebrae at any junction are characterized by features retained from two adjacent regions in the vertebral column. Currently, there is no published literature available that describes the prevalence or morphology of thoracolumbar transitional vertebrae (TLTV). The aim of this study was to identify the qualitative characteristics of transitional vertebrae at the thoracolumbar junction and establish a technique to differentiate the various subtypes that may be found. A selection of vertebral columns from skeletal remains (n = 35) were evaluated in this study. Vertebrae were taken based on features that are atypical for vertebrae in each relative region. The transitional vertebrae were qualitatively identified based on overlapping thoracic and lumbar features of vertebrae at the thoracolumbar junction. The following general overlapping characteristics were observed: aplasia or hypoplasia of the transverse process, irregular orientation on the superior articular process and atypical mammillary bodies. The results show that the most frequent location of the transitional vertebrae was in the thoracic region (f = 23). The second most frequent location was in the lumbar region (f = 10). In two specimens of the selection (f = 2), an additional 13th thoracic vertebra was present which functioned as a transitional vertebra. This study concluded that one can accurately identify the characteristics of transitional vertebrae at the thoracolumbar junction. In addition, the various subtypes can be differentiated according to the region in the vertebral column the vertebra is located in and the relative number of vertebral segments in the adjacent regions of the vertebral column. This provides a qualitative tool for researchers to differentiate the transitional vertebrae from distinctly different typical thoracic or lumbar vertebrae at the thoracolumbar junction.

Vertebral Formulae and Congenital Vertebral Anomalies in Guinea Pigs: A Retrospective Radiographic Study

“…In a minority of guinea pigs, we also identified previously undescribed vertebral formulae with five and seven lumbar vertebrae (Table 1). Respective numbers of thoracic and lumbar vertebrae can be altered in animals by homeotic transformation and cranial-caudal border somatic shifts [7,28]. In comparison with slow-running mammals, a low variability in numerical changes of the thoracolumbar part of the vertebral column was observed in previous studies in fast-running and agile mammals [29], although a most recent hypothesis posits that range of dorsoventral movement of the vertebral column during running and leaping is a most important parameter for numerical changes of presacral vertebrae [30].…”

“…In our study, CVA were localized predominantly in thoracolumbar junction, and transitional vertebra was the most common pathology. The transitional vertebra has a combined morphology of two adjacent vertebral regions, and various subtypes of the transitional vertebra can be differentiated in human and veterinary medicine [18,21,22,28]. In contrast to the LTV, very little is known about the TTV.…”

Variation in Global Spinal Sagittal Parameters in Asymptomatic Adults with 11 Thoracic Vertebrae, four Lumbar Vertebrae, and six Lumbar Vertebrae

“…However, in older children and adults, thoracic outlet syndrome or aneurysm formation can occur 11 , 24 . Supernumerary ribs, as seen in trisomy 21 syndrome, are rare variants 11 , 17 . Therefore, we excluded such variation in choosing adult asymptomatic volunteers.…”

Ex vivo virtual and 3D printing methods for evaluating an anatomy‐based spinal instrumentation technique for the 12th thoracic vertebra

“…The T12 vertebra represents an anatomical bridge between the lumbar and thoracic spine (Waxenbaum & Futterman, ). This transitional segment is vital for the biomechanical stability of thoracolumbar instrumented constructs and can present several challenges in instrumentation owing to anatomical characteristics distinct from those of the other thoracic vertebral levels (Du Plessis, Greyling, & Page, ; Wigh, ). The pedicles of the T12 vertebra are typically divergent, which is an important consideration during pedicle screw planning and insertion (Lafage et al, ).…”