Age / Sex : 78 / M

Chief complaint : Left buttock to lower extremity radicular pain

Question

1. (Orange Arrow) : What is the Diagnosis?

Two weeks later, you can see the final diagonosis with a brief discussion of this case (Please submit only one answer).

Courtesy : 이영준 (Eugene Lee), 분당서울대학교병원 (Seoul National University Bundang Hospital)

1. Lumbosacral Transitional Vertebra (LSTV) 2. Left L5

Discussion

• Disease definition

    pseudoarthrosis between the transverse process of the LSTV and the sacral ala

    à extraforaminal compression of the exiting nerve root (L5) below the LSTV

Subtypes of lumbosacral transitional vertebra using Castellvi classification              

 (1) type I : enlarged transverse process only - unilateral (IA), bilateral (IB)             

 (2) type II : incomplete fusion with a pseudoarthrosis  - unilateral (II A), bilateral (II B)

                    -->”possible extraforaminal nerve root compression”

 (3) type III : complete fusion - unilateral (III A), bilateral (III B)

 (4) type IV : mixture of types IIA and IIIA

  - Prevalence of extraforaminal nerve root compression below lumbosacral transitional vertebrae.

      Skeletal Radiol (2014) 43:55-60

    - Effect of Spinal Segment Variants on Numbering Vertebral Levels at Lumbar MR Imaging.

      Radiology. 2011;259 (1): 196-202

    - Lumbosacral transitional vertebrae: classification, imaging findings, and clinical relevance.

      AJNR Am J Neuroradiol. 2010;31 (10): 1778-86

    - Lumbosacral transitional vertebrae: association with low back pain.

      Radiology. 2012;265 (2): 497-503