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
Ans:B. Cervical Spine is the most common site.
Spondylolisthesis is shown in the image.
- 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.