The lumbosacral transitional vertebra (LSTV) is a common lumbar vertebral variation characterized by unilateral or bilateral enlarged transverse processes. When the enlargement of the transverse processes alters the local biomechanics of LSTV, it may give rise to a series of clinical symptoms known as Bertolotti syndrome. The main manifestations include pain in the lumbosacral region, buttocks, outer side of the lower limbs, numbness, and symptoms related to the sciatic nerve. LSTV is often classified using the Castellvi classification. The presence of lumbosacralization and sacralization of vertebrae in LSTV makes it challenging to accurately locate and number LSTV. So various anatomical landmarks and spinal parameters have been proposed to assist in the localization and numbering of LSTV, but they all have a certain error rate. Even after the lumbar vertebrae is clearly numbered, there is often controversy over the baseline selection for preoperative spinal parameters. Currently, the horizontal level of S₁ is considered the optimal measurement baseline, but this conclusion needs further confirmation in a clinical context. The main basis for LSTV diagnosis is imaging signs, while the diagnosis of Bertolotti syndrome requires local injection of local anesthetics or corticosteroids into the pseudo-joint and the exclusion of other degenerative diseases of the lumbar spine. The treatment of Bertolotti syndrome includes conservative and surgical approaches. Common surgical procedures include fusion and decompression, both of which can achieve good short-term outcomes. However, due to the limited number of patients studied or a lack of direct comparisons, it is challenging to determine the superiority of these two methods in terms of medium to long-term effectiveness. This article provides a comprehensive review of the symptoms and causes of Bertolotti syndrome, preoperative localization and numbering of LSTV, baseline selection for preoperative spinal parameter measurements, and treatment methods.

Lumbosacral region; Vertebral body; Review