php – Fatal error

Me tira el siguiente error al momento de querer consultar un Ticket que ya tengo en mi base de datos
Fatal error: Uncaught PDOException: SQLSTATE(HY093): Invalid parameter number: number of bound variables does not match number of tokens in C:xampphtdocsHelpDeskmodelsTicket.php:38
Stack trace:
#0 C:xampphtdocsHelpDeskmodelsTicket.php(38): PDOStatement->execute()
#1 C:xampphtdocsHelpDeskcontrollerticket.php(12): Ticket->listar_ticket_x_usu(‘1’)
#2 {main}
thrown in C:xampphtdocsHelpDeskmodelsTicket.php on line 38/>

Mi codigo es

controller.php

<?php
    require_once("../config/conexion.php");
    require_once("../models/Ticket.php");
    $ticket = new Ticket();

    switch($_GET("op")){
        case "insert":
            $ticket->insert_ticket($_POST("usu_id"),$_POST("cat_id"),$_POST("tick_titulo"),$_POST("tick_descrip"));
        break;

        case "listar_x_usu":
            $datos=$ticket->listar_ticket_x_usu($_POST("usu_id"));
            $data= Array();
            foreach($datos as $row){
                $sub_array = array();
                $sub_array() = $row("tick_id");
                $sub_array() = $row("cat_nom");
                $sub_array() = $row("tick_titulo");
                $sub_array() = '<button type="button" onClick="ver('.$row("tick_id").');"  id="'.$row("tick_id").'" class="btn btn-inline btn-primary btn-sm ladda-button"><i class="fa fa-eye"></i></button>';
                $data() = $sub_array;
            }

            $results = array(
                "sEcho"=>1,
                "iTotalRecords"=>count($data),
                "iTotalDisplayRecords"=>count($data),
                "aaData"=>$data);
            echo json_encode($results);
        break;
    }
?>

models/ticket.php

<?php
    class Ticket extends Conectar{

        public function insert_ticket($usu_id,$cat_id,$tick_titulo,$tick_descrip){
            $conectar= parent::conexion();
            parent::set_names();
            $sql="INSERT INTO tm_ticket (tick_id,usu_id,cat_id,tick_titulo,tick_descrip, est) VALUES (NULL,?,?, ?,?,'1');";
            $sql=$conectar->prepare($sql);
            $sql->bindValue(1, $usu_id);
            $sql->bindValue(2, $cat_id);
            $sql->bindValue(3, $tick_titulo);
            $sql->bindValue(4, $tick_descrip);
            $sql->execute();
            return $resultado=$sql->fetchAll();
        }

        public function listar_ticket_x_usu($usu_id){
            $conectar= parent::conexion();
            parent::set_names();
            $sql="SELECT 
                tm_ticket.tick_id,
                tm_ticket.usu_id,
                tm_ticket.cat_id,
                tm_ticket.tick_titulo,
                tm_ticket.tick_descrip,
                tm_usuario.usu_nom,
                tm_usuario.usu_ape,
                tm_categoria.cat_nom
                FROM 
                tm_ticket
                INNER join tm_categoria on tm_ticket.cat_id = tm_categoria.cat_id
                INNER join tm_usuario on tm_ticket.usu_id = tm_usuario.usu_id
                WHERE
                tm_ticket.est = 1
                AND tm_usuario.usu_id=1";
            $sql=$conectar->prepare($sql);
            $sql->bindValue(1, $usu_id);
            $sql->execute();
            return $resultado=$sql->fetchAll();
        }

    }
?>

Muchas gracias!