Radiopaedia Courses 25% Discount in response to COVID-19 ends on October 31 EXPLORE OUR COURSES

Inverted Napoleon hat sign

Case contributed by Dr Renan Ibrahem Adam


Low back pain

Patient Data

Age: 45
Gender: Male

There is a high grade anterior spondylolisthesis of L5 vertebra over S1 with overlapping over the sacrum.

Case Discussion

The inverted Napoleon hat sign indicates the presence of bilateral spondylolysis and significant spondylolisthesis. The dome of the hat is formed by the overlying body of L5 vertebra and the brim is formed by downward rotation of the transverse processes.

PlayAdd to Share

Case information

rID: 39463
Published: 5th Sep 2015
Last edited: 14th Aug 2019
Inclusion in quiz mode: Excluded

Updating… Please wait.

 Unable to process the form. Check for errors and try again.

 Thank you for updating your details.