Spondylolithesis

DID TIP

 

Dysplastic

- 20%

- abnormal L5 / S1

- around 6 years old

- tendency to worse slips

- worse symptoms as posterior elements move forwards

- may have SB occulta

- L5 kyphosis

- L5 nerve root

 

Isthmic

- 50%

- L5/S1

- adolescents

- L5 lordosis

- L5 nerve root

- may be acute / chronic / elongated and thinned

 

Degenerative

- facet joints

- L4/5

- slips limited to Grade II

 

Trauma

- fracture not of pars

- neural elements

 

Iatrogenic

- laminectomy

 

Pathological

- weak posterior elements

- OI, Larsen's, Marfans