One of these:
$ragioni = new WP_Query( array(
'connected_type' => 'ragioni_to_case',
'connected_items' => get_queried_object_id(),
'nopaging' => true,
) );
if ( $ragioni->have_posts() ) :
...
while ( $ragioni->have_posts() ) : $ragioni->the_post();
...
endwhile; endif;