usort сортировка по совпадению

usort($dbDetails,  function  ($a, $b) use ($detail) {
    $adate = (strpos($a['detail_num'], $detail) !== false);
    $bdate = (strpos($b['detail_num'], $detail) !== false);
    if (!($adate ^ $bdate)) return strcmp($a, $b);
    return $adate ? -1 : 1;
    });

        if(!empty($dbDetails)){
            $result=array();
            foreach($dbDetails as $key=>$val){
                if((strcasecmp($detail,$val['detail_num'])==0)){
                    unset($val['detail_analog']);
                    $val['detail_parent']=1;
                array_unshift($result,$val);
                }
                else array_push($result,$val);
                unset($dbDetails[$key]);

            }
            unset($dbDetails);
            $dbDetails =$result;

        }