Spondylolisthesis refers to the forward displacement of one vertebral body over another, most commonly occurring at L5 over S1. It is classified based on etiology, with isthmic spondylolisthesis being the most common type caused by pars interarticularis defects. Symptoms include leg or back pain, numbness, and weakness. Treatment depends on the severity of the slip and symptoms, ranging from observation to surgery to decompress nerves or fuse vertebrae.

1. Spondylolisthesis
Done by: Qutaiba A.
Jawarneh

2.  articular processes: are
projections of the vertebra
that serve the purpose of
fitting with an adjacent
vertebra.
 Facet joint: re a set
of synovial, plane
joints between the articular
processes of two adjacent
vertebrae.
 Pars interarticulars: is the part
of vertebra located between
the inferior and
superior articular processes of
the facet joint.

3. Spondylolisthesis
 refers to the forward displacement of one
vertebral body with respect to the one
beneath it. This most commonly occurs at
the lumbosacral junction with L5 slipping
over S1, but it can occur at higher levels as
well.
 Spondylolysis non-slipped pars defect & is almost
always a precursor to the actual forward slippage.

5.  The first theory proposed a failure of ossification during embryonic development,
leading to a pars interarticularis defect at birth
 The second theory demonstrated that the pars defect began to appear around age
six and became progressively more common till age 16. After age 16, the
incidence fell and rarely developed after adolescence
 It is currently thought that the defect develops from small stress fractures that fail
to heal and form a chronic nonunion.

6. Classifiction
 It is classified on the basis of etiology into the following five types [1] :
 Congenital or dysplastic
 Isthmic
 Degenerative
 Traumatic
 Pathologic
 Iatrogenic

7. Dysplastic spondylolisthesis
Is a true congenital spondylolisthesis that occurs because
of malformation of the lumbosacral junction with small,
incompetent facet joints.
Very rare, but tends to progress rapidly
Often associated with more severe neurological deficits.

8. Isthmic spondylolisthesis “spondylolytic”
 is the most common subtype and is caused by pars interarticularis defects.
 Subtype A: It is believed that "biomechanical stress," such as repetitive mechanical strain from
heavy work or sports, causes a fatigue fracture. Most common type in people less than 50 yrs
 Subtype B: includes individuals who have an elongated but intact pars. This is believed to be
secondary to repeated fracture and subsequent healing of the stress fracture in the pars
 SUB-TYPE C: Extremely rare and result from an acute pars fracture, often as result of traumatic
lumbar hyperextension injury

10. Degenerative spondylolisthesis
 Is Mostly seen in people over 50 yrs – affects female more than male
 Every level of the spine is composed of a disc in the front and paired facet joints in
the back. The disc acts as a shock absorber in between the vertebrae, whereas the
paired facet joints restrain motion. They allow the spine to bend forwards (flexion)
(flexion) and backwards (extension) but do not allow for a lot of rotation.
 As the facet joints age, they can become incompetent and allow too much flexion,
allowing one vertebral body to slip forward on the other.

11. Traumatic spondylolisthesis
 Results from a traumatically-induced fracture to the neural arch other
than the pars region.
 Hangman's Fracture this fracture commonly seen in cervical
spine, but also may occur within lumbar spine.

12. Pathological spondylolisthesis
Generalized or systemic disorders of bone may affect the
neural arch of the spine and allow spondylolysis or
spondylolisthesis to occur.
• Osteoporosis
• Paget's disease
• Metastatic carcinoma

13. Iatrogenic spondylolisthesis
 Is a complication of lumbar anterior interbody fusion (LAIF),
which ironically is often used to stabilize spondylolisthesis. Either
the vertebrae above o below develops a pars fracture.
 Laminectomy procedures, which are used for decompressing
symptomatic disc herniations in the spine, will result in an overload
of weight-bearing stress on the contralateral pars and, in some
patients, result in a pars fracture.

14. Symptoms
 Spondylolysis commonly is asymptomatic.
 Symptoms (25%)
 Nerve symptoms are similar to symptoms seen with a herniated disc.
• Leg pain
• Electric shock-like symptoms traveling down the leg
• Numbness or tingling in the legs and feet
• Muscle weakness of the legs
• Cauda equina syndrome (medical emergency)
 Bowel or bladder problem
 Numbness around the genitals

15. Limitations of Techniques
• Radiography of the lumbar spine is limited by its inability to detect
stress reactions in the pars interarticularis that have not progressed
to complete fracture.
• CT of the lumbar spine is not sensitive for detecting early acute
stress reactions in the pars interarticularis where there is only
marrow edema and microtrabecular fracture.
• MRI of the lumbar spine can easily identify acute stress reactions in
the pars interarticularis. However, direct identification of pars
defects (old stress) may be slightly more difficult with MRI than
with CT.

16. Treatment
o If the slip is small and the symptoms are manageable, then
treatment is most often with observation. In children, this may
include activity restrictions, such as withholding the child from
participation in some sports.
o When the slip is more significant, there may be a higher risk of the
problem progressing, and surgery may be favored. In addition,
patients who have symptoms of nerve compression are more likely
to have surgery recommended.