how safe are PDO prepared statements

Started using PDO prepared statements not too long ago, and, as i understand, it does all the escaping/security for you.

for example, assuming $_POST['title'] is a form field.

$title = $_POST['title'];
$query = "insert into blog(userID, title) values (?, ?)"
$st = $sql->prepare($query);
$st->bindParam(1, $_SESSION['user']['userID'], PDO::PARAM_INT);
$st->bindParam(2, $title);
$st->execute();

Is this really safe? Do i have to do anything else? what else do i have to take into consideration?

Thanks.