$collection->getSelect()->joinLeft(
                            'rating_option_vote_aggregated',
                            'e.entity_id = rating_option_vote_aggregated.entity_pk_value',
                            array('vote_count' => 'SUM(rating_option_vote_aggregated.vote_count)'))
                    ->group('e.entity_id')
                    ->order('vote_count ' . $this->getCurrentDirectionReverse());