Methods and devices are provided for anchoring a ligament or tendon to bone. In general, various inserter tools are provided for simultaneously delivering an expandable sheath and an expander into bone. With both components of the implant mounted on the same tool, the sheath and a ligament can be advanced into a bone hole and the expander, which trails behind the sheath during delivery of the sheath, can be advanced into the sheath to expand the sheath and anchor the sheath and ligament within the bone hole.