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Definition

Bertolotti’s syndrome is a clinical term used when low back pain is associated with the presence of a lumbosacral transitional vertebra (LSTV).

The term does not describe a specific disease, but rather a situation in which:

• a congenital anatomical variant is present

• symptoms exist that may be related to this variant

• other explanations are insufficiently fitting

In the medical literature, there is no universally accepted definition of Bertolotti’s syndrome. The term is used differently depending on clinical context, discipline, and interpretation.

Historical background

The syndrome was described in 1917 by the Italian physician Mario Bertolotti, who suggested a relationship between low back pain and abnormalities at the transition between the lumbar spine and the sacrum.

In his original description, the emphasis was on:

• enlarged transverse processes of the lowest lumbar vertebra

• contact or fusion with the sacrum

• mechanical low back pain

Since then, the concept has been revised and expanded multiple times, partly due to advances in imaging and a better understanding of biomechanics.

Evolution of the concept

Where Bertolotti’s syndrome was initially regarded as a clearly defined cause of low back pain, it is now approached with much greater caution.

Important developments in the literature include:

• recognition that lumbosacral transitional vertebrae are relatively common

• insight that many people with an LSTV are completely asymptomatic

• awareness that low back pain is usually multifactorial

• increasing emphasis on clinical context rather than anatomy alone

As a result, the focus has shifted from an “abnormality that causes pain” to a possible contributing factor within a broader clinical picture.

Lack of clear boundaries

An important characteristic of Bertolotti’s syndrome is the absence of clear diagnostic boundaries.

There is:

• no fixed criterion for when an LSTV causes symptoms

• no objective test that confirms or excludes the syndrome

• no uniform definition in guidelines or classifications

This means that use of the term is always dependent on clinical interpretation, and caution is required when drawing conclusions.

Clinical term, not an anatomical diagnosis

In contrast to the lumbosacral transitional vertebra itself, which can be anatomically described and classified, Bertolotti’s syndrome is a clinical description.

This means:

• the term refers to symptoms, not just anatomy

• the diagnosis cannot be based on imaging alone

• symptom pattern and clinical course are decisive

Many publications therefore emphasize that the term is primarily descriptive and does not denote a distinct disease entity.

Current view in the literature

In recent reviews and overview articles, Bertolotti’s syndrome is increasingly approached as:

• part of a clinical spectrum

• a possible factor in selected patients

• not a general explanation for low back pain

This approach aligns with the broader trend in medicine to avoid automatically labeling anatomical variations as pathological.

Summary

• Bertolotti’s syndrome is a clinical term, not a fixed diagnosis

• There is no universal definition

• The term originated in 1917

• Its conceptual meaning has shifted over time

• Anatomical variation alone is insufficient to explain symptoms

• Clinical context is essential when using the term

Sources

Scientific and medical literature
https://www.ncbi.nlm.nih.gov/books/NBK585032/
https://orthopedicreviews.openmedicalpublishing.org/article/24980-a-comprehensive-update-of-the-treatment-and-management-of-bertolotti-s-syndrome-a-best-practices-review
https://www.ijssurgery.com/content/9/42
https://pmc.ncbi.nlm.nih.gov/articles/PMC7964015/
https://pubmed.ncbi.nlm.nih.gov/3974903/

Historical and radiological context
https://pubs.rsna.org/doi/pdf/10.1148/rg.291085200