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Castellvi classification of lumbosacral transitional vertebrae

The Castellvi classification is used for lumbosacral transitional vertebra (LSTV):

  • type I: enlarged and dysplastic transverse process (at least 19 mm)
    • Ia: unilateral
    • Ib: bilateral
  • type II: pseudoarticulation of the transverse process and sacrum with incomplete lumbarization/sacralization; enlargement of the transverse process with pseudoarthrosis
    • IIa: unilateral
    • IIb: bilateral
  • type III: transverse process fuses with the sacrum and there is complete lumbarization or sacralization, enlarged transverse process with complete fusion
    • IIIa: unilateral
    • IIIb: bilateral
  • type IV: type IIa on one side and type III on the contralateral side

History and etymology

This classification system was initially described by Castellvi et al in 1984, in a study examining the association of lumbosacral transitional vertebrae with herniated lumbar discs 3.

Related pathology

Anatomy: Spine
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Article information

rID: 24141
Synonyms or Alternate Spellings:
  • Castellvi classification
  • Castellvi's classification
  • Lumbosacral transitional vertebra (Castellvi classification)

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Cases and figures

  • Figure 1: normal
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  • Case 1: Castellvi type Ia
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  • Figure 2: type 1a
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  • Case 2: Castellvi IIa
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  • Figure 3: type 1b
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  • Case 3: Castellvi type IIa
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  • Figure 4: type 2a
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  • Case 4: Castellvi IIb
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  • Figure 5: type 2b
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  • Case 5: Castellvi type IIIb
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  • Figure 6: type 3a
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  • Figure 7: type 3b
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