Wiltse classification (spondylolisthesis)

Spondylolisthesis can be classified according to broad etiologies as described by Wiltse in 1981 . Typically when reporting studies with spondylolisthesis the Wiltse type is merely stated without referring to its number, whereas the grade of spondylolisthesis is explicitly stated: e.g. "Grade 1 degenerative spondylolisthesis of L5 on S1" rather than "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)