Methods of injecting curable material within a bone structure, such as vertebroplasty, include locating a distal end of an access cannula within the bone structure. A channel creating device is inserted into a cannula lumen. A distal segment of the channel creating device is distally advanced from cannula distal end and into the bone structure. A curved channel is created in the bone structure with the distally advancing distal segment. A distal portion of a cavity creating device is then inserted into the cannula lumen, with the distal portion including an expandable body carried by an elongated body. The distal portion is distally advanced, following a path of the curved channel. The expandable body is transitioned to the expanded state to form a cavity in the bone structure. Finally, curable material is delivered to the cavity.