A minimally invasive applicator device for treatment of intervertebral tissue containing at least one target nerve includes an insertion device having a proximal end and a distal end for insertion into the intervertebral tissue containing at least one target nerve, an ultrasound transducer device coupled to the distal end of the insertion device, and an external RF power generator electrically that provides power to the ultrasound transducer device. The ultrasound transducer device includes an array of a plurality of transducer crystals which are all aligned along a line defined by an axis enclosed by each of the plurality of transducer crystals disposed sequentially and longitudinally adjacent each other along the axis to form a customized flexible array along the applicator device. Ultrasound radiative output treatment outward from the axis of the transducer crystals allows for treatment of the intervertebral tissue containing at least one target nerve.