Image Based Question-71968

Regarding the following condition as shown in the X ray ,which of the following statements is false?

A. Most common site is between L5 – S1 and between L4 — L5.

B. Cervical Spine is the most common site

C. Beheaded scottish terrier sign

D. Best viewed in sagittal images of spine i.e. lateral and oblique X rays of spine and saggital & axial views of CT & MRI

Correct Answer » B Explanation

Ans:B. Cervical Spine is the most common site.

Spondylolisthesis is shown in the image.

SPONDYLOLISTHESIS

• Abnormal AP translation of 2 vertebral bodies relative to each other.

• Secondary to a defect in the pars interarticularis (spondylolysis) or the posterior ligamentous-bony restraints.

• Physical examination reveals limited extension and pain with extension.

• Commonly involves the L4—L5 and L5—S1 levels.

• It is best viewed (or seen earliest) in sagittal images of spine i.e. lateral and oblique X rays of spine and saggital & axial views of CT & MRI.

• AP views of X ray can only be used to demonstrate indirect evidences (eg. inverted Napoleon’s hat sign) of late/ severe spondylolisthesis.

• Beheaded (without head) Scottie terrier sign is seen in the Xray.

• “Inverted Napoleon’s Hat” sign: A severe degree of spondylolisthesis at L5 – S1 can be identified on A-P view by ventrocaudal displacement of L5 over sacrum and creates curvilinear densities.