Usually what I do, when creating controlers is:
Create nurbscurve and leave it at 0,0,0.
Then group the controler so that both group and controler has a pivot in world center.
Then select the joint, shift select the group (NOT the controler, do it from the outliner) and do a point and orient constrain without maintaining offset. That way the group will jump to the joint and get it’s orientation, taking the controler with it, but keeping its values at zero.
Then you can delete the two constraints from the group, and you are set to do any further setup.