Spondylolisthesis is a term denoting anterolisthesis of a vertebra relative to the segment below, typically due to spondylolysis (pars interarticularis defects). This term is often used to denote anterolisthesis from any cause (e.g. degenerative spondylosis). 



Spondylolisthesis is most frequent at L5/S1 and to a lesser degree L4/5. 


One of the most commonly used classification systems to convey the etiology of a spondylolisthesis is the Wiltse Classification 4. When reporting, typically the Wiltse type is stated, but without the number (i.e. "Grade 1 degenerative spondylolisthesis of L5 on S1" instead of "Grade 1, Type III spondylolisthesis").

  • type I (dysplastic/congenital): translation is secondary to an abnormal neural arch
  • type II (isthmic): translation is secondary to a lesion involving the pars interarticularis
    • subtype a (lytic): secondary to stress fracture, in most cases attributed to repeated extension and/or twisting motions
    • subtype b (elongated pars): result of multiple injury/healing events leading to elongation of the pars
    • subtype c (acute pars fracture): secondary to a single event and is rare
  • type III (degenerative): result of chronic instability and intersegmental degenerative changes
  • type IV (post-traumatic): fracture in a region other than the pars leading to slippage. 
  • type V (pathological): diffuse or local disease compromising the usual structural integrity that prevents slippage
  • type VI (iatrogenic)

See: spondylolisthesis grading

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Cases and figures

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    L5/S1 grade II sp...
    Figure 1: grading spondylolisthesis
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    Case 1: L4/5
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    Case 2: L4/5
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    Case 3: L5/S1
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    Case 5
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    Case 6: L5/S1
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    Case 7: L4/5
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