Complex Orderby

I have a list of movies where the year and imdbTitle are stored in postmeta.

I need to sort

1. By year
2. By imdbTitle and post_title by relavence to the search “the rundown”
3. By post_content

Here are my args for query_posts

Array
(
    [offset] => 0
    [meta_query] => Array
        (
        )

    [s] => the rundown
    [orderby] => meta_value_num
    [meta_key] => year
    [order] => asc
)

I hook into post_where and add

$where .= " OR ({$wpdb->postmeta}.meta_key = 'imdbTitle' AND {$wpdb->postmeta}.meta_value LIKE '%".get_search_query()."%')";

which allows the imdbTitle to be search for as well as the post_title

I’ve then hooked into the posts_orderby and added the following sql

(CASE
    WHEN
        wp_posts.post_title LIKE '%the rundown%' OR
        wp_postmeta.meta_value LIKE '%the rundown%' THEN 1
    WHEN
        (wp_posts.post_title LIKE '%the%' AND
        wp_posts.post_title LIKE '%rundown%' ) OR
        (wp_postmeta.meta_value LIKE '%the%' AND
        wp_postmeta.meta_value LIKE '%rundown%' ) THEN 2
    WHEN
        wp_posts.post_title LIKE '%the%' OR
        wp_postmeta.meta_value LIKE '%the%' OR
        wp_posts.post_title LIKE '%rundown%' OR
        wp_postmeta.meta_value LIKE '%rundown%' THEN 3
    WHEN
        wp_posts.post_content LIKE '%the rundown%' THEN 4
    ELSE 5
END)

This is added to the end of the order by which also has this at the start

wp_postmeta.meta_value+0 ASC,

I think the issue is wp_postmeta.meta_value+0 ASC because both the year and imdbTitle are postmeta.

Is there a way to get around this? Or a better way to do this?