I finally figured it out. Here is the way to add Help Topic to the staff page.

vi /var/www/include/staff/tickets.inc.php
1. Comment out
//$sortOptions=array('date'=>'ticket.created','ID'=>'ticketID','pri'=>'priority_urgency','dept'=>'dept_name');
Replace with:
$sortOptions=array('date'=>'ticket.created','ID'=> 'ticketID','pri'=>'priority_urgency','dept'=>'dept_name','helptopic'=>'helptopic');
2. COmment out:
//$page=($_GET && is_numeric($_GET))?$_GET;
//$qselect = 'SELECT DISTINCT ticket.ticket_id,lock_id,ticketID,ticket.dept_id,ticket.staff_id,subject,name,email,dept_name '.
',ticket.status,ticket.source,isoverdue,isanswered,ticket.created,pri.* ,count(attach.attach_id) as attachments ';
//$qfrom=' FROM '.TICKET_TABLE.' ticket '.
// ' LEFT JOIN '.DEPT_TABLE.' dept ON ticket.dept_id=dept.dept_id ';
Replace with:
$page=($_GET && is_numeric($_GET))?$_GET;
$qselect = 'SELECT DISTINCT ticket.ticket_id,lock_id,ticketID,ticket.dept_id,ticket.staff_id,subject,name,ticket.email,dept_name,helptopic '.
',ticket.status,ticket.source,isoverdue,ticket.created,pri.*,count(attach.attach_id) as attachments ';
$qfrom=' FROM '.TICKET_TABLE.' ticket LEFT JOIN '.DEPT_TABLE.' dept ON ticket.dept_id=dept.dept_id '.
3. Search for href in the file and add this:
<?=$qstr?>" title="Sort By Help Topic<?=$negorder?>">Help Topic
4. Search for the nowrap section and add this:
<?=($row) ? $row : ' ';?>