A system for performing an off-axis bone augmentation procedure is described. The system comprises an access cannula having a distal end for positioning in the tissue, and a steerable assembly comprising a steerable instrument and a deformable conduit. The steerable instrument is capable of being removably and at least partially disposed in the deformable conduit and comprises a control element and a deflectable portion operatively connected to the control element. The steerable instrument is capable of assuming at least a substantially straight configuration and a curved configuration when the deflectable portion protrudes from the distal end of the access cannula. The steerable instrument is actuatable to move the deflectable portion of the steerable instrument away from a longitudinal axis of the access cannula in order to deform the deformable conduit so that the deformable conduit occupies a deformed position. The steerable instrument is capable of being retracted from the deformable conduit after the deformable conduit occupies the deformed position, and an implant or other treatment device is deliverable through the deformable conduit to a tissue location after the deformable conduit occupies the deformed position.
