Bertolotti syndrome (lumbosacral transitional vertebrae)

Case contributed by Dr Shailaja Muniraj


Vague pain over the left gluteal region

Patient Data

Age: 25 years
Gender: Male

The left transverse process of L5 is enlarged and dysplastic (mega-apophysis). This transverse process is seen to articulate with its ipsilateral sacral ala, suggestive of pseudoarthrosis. Features suggest a type II lumbosacral transitional vertebra.

Case Discussion

Bertolotti syndrome is a developmental abnormality wherein, the transverse process of the caudal most lumbar vertebrae is enlarged and shows pseudoarticulation with the sacral ala or ilium, leading to an uncommon cause of chronic lower back and gluteal region pain in young individuals.

Radiologists should try to recognize this condition, particularly regarding pseudoarticulation, as there is potential clinical significance due to the following factors:

  • pseudoarticulation causes biomechanical stress - reduces mobility on the ipsilateral side or alternatively causes hypermobility on the contralateral side, leading to pain
  • ipsilateral facetal arthropathy
  • iliopsoas and quadratus lumborum muscle strain
  • narrowed neural foramina by the dysplastic transverse process, causing nerve root compression
  • disc herniation above the level of transitional vertebra
  • pseudoarticulation may lead to a stress reaction, seen as edema or sclerosis

Apart from the above, identifying transitional vertebrae may prevent incorrect surgery.

Special thanks to Dr HT Gururaj

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Case information

rID: 60570
Published: 25th May 2018
Last edited: 14th Aug 2019
Inclusion in quiz mode: Included

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