Bertolotti's syndrome in low-backache population: Classification and imaging findings

Abstract

Objective: Lumbosacral transition vertebrae (LSTVs) are associated with alterations in biomechanics and anatomy of spinal and paraspinal structures, which have important implications on surgical approaches and techniques. LSTVs are often inaccurately detected and classified on standard anteroposterior radiographs and magnetic resonance imaging. The use of whole-spine images as well as geometric relationships between the sacrum and lumbar vertebra increases accuracy. The diagnosis of symptomatic LSTV is considered with appropriate patient history and imaging studies. This study aimed to classify the anatomical variations in LSTV and determine, by plain radiography, if there exists a relationship between sacralization and low backache (LBP).

Materials and methods: Five hundred lumbosacral radiographs of LBP patients were examined after obtaining prior consent from the patient and approval from the "institutional ethics committee." Data collection consisted of the patient's age at the time of imaging gender and number of lumbar vertebral bodies. Dysplastic transverse processes were classified according to the Castellvi radiographic classification system. The incidence of sacralization in patients and the control groups was reported, and the anomaly was compared according to the groups.

Results: Of these patient groups, 134 were classified as positive for sacralization, which resulted in an incidence of 26.8%. The most common anatomical variant was Castellvi Type IA (7.6%). There were no statistically significant differences between men and women who had anomaly (P = 0.9256). Higher incidences of Type IB and Type IIB were found in men, but those results were not statistically significant (P = 0.133 and P = 0.581, respectively) when compared with the female group. Daily frequency and intensity of LBP were assessed in patients using visual analog scale (VAS) scores. The patients with LBP and no malformation reported an average pain level on the VAS for pain of 2.2 versus 5.2 in patients with LBP and a transitional vertebra, respectively.

Conclusion: Based on our data, we conclude that lumbosacral transitional segments are a common cause in the low-backache population. However, no relationship was found between age and genders in this study. However, in comparison with the nonspecific low-backache group, the VAS scores were significantly higher and the pain duration was significantly longer in the LSTV group.

Keywords: Castellvi classification; Low backache; Lumbarization; Lumbosacral transition vertebra; Sacralization.

Figure 1

Illustration demonstrating the Castellvi classification of lumbosacral transition vertebrae

Figure 2

Illustration depicting the O’Driscoll classification system of S1-2 disk morphology