The bottom border of the table row (border-bottom) as an image

There is a bootstrap-table:

When you click on the lower boundary of the series leaves a hint. I want to make this border in the form of an arrow down. Is it possible to do something like this? I tried border-image - it does not work (although on other elements div, textarea .. works fine).

I tried:
Sss

tr{ border-image-slice: 0 0 22 0 !important; border-image-width: 20px 20px 20px 20px !important; border-image-outset: 0px 0px 0px 0px !important; border-image-repeat: stretch stretch !important; border-image-source: url("http://wordpress/wp- content/uploads/2015/01/detailsDownSmall.png");