A trans-soft tissue anchor implantation system in one embodiment includes a positioning wire having a tissue penetrating distal tip, a cannula for passage through the soft tissue and a suture anchor. The cannula has an axial lumen therethrough sized to accommodate at least the positioning wire, a thin-walled distal portion and a tissue engaging feature, such as an arcuate groove, on at least a portion of an outer surface of the cannula proximal of and adjacent to the distal portion. Tissue, such as a tendon, expands into the groove allowing a surgeon to manipulate the tissue with the cannula. Also featured is a cannula having a first curved section having a first thin-walled distal portion and a second curved section having a second thin-walled distal portion, the first and second curved sections capable of being moved relative to each other from an initial, low-profile configuration, with the second section nesting at least partially within the first section to present less than a full circumference of cannula to the soft tissue, to a second, larger configuration defining an axial cannula lumen therethrough.
