Spondylolysis

Spondylolisthesis is a spinal disorder affecting roughly 3-7% of the general population. Below are some clinical evaluation of the disorder as well as what to look for in the demonstrated X-ray.

Spondylolysis

SPONDYLOLYSIS = Defect in pars interarticularis portion of lamina.

Etiology:

Repeated Microtrauma

Heredity component (hypoplastic pars)

Clinical:

May be asymptomatic

May present with low back pain

3-7% of general population (all ages)

Athletes -Increased to 23-62%

Males 2-4 more than Females

95% at L5 level

Bilateral pars defects can lead to spondylolisthesis

XRAY

Most sensitive projection- lateral views

Most specific projection- oblique views (Scottie dog collar)

May not be seen if plane of defect lies near sagittal plane

CT

Incomplete vertebral ring

Linear lucency best seen on sagittal reconstructions

MRI

Acute stress reaction demonstrates high T2 signal and low T1 signal

Fracture line seen best on sagital T1 images

If defect low on T2 = chronic process

False negatives can occur with facet joint arthropathy with osteophytes obscuring pars defect

 

Remember- “The Eyes Will Not See What The Brain Does Not Know”