Systems and tools are provided for anchoring a ligament or tendon to bone. In one embodiment, a sheath is provided having a first sidewall with proximal and distal ends and a second sidewall with proximal and distal ends. The distal ends of the first and second sidewalls can be coupled to one another by a hinge pin such that the first and second sidewalls pivot relative to one another about the hinge pin. A sheath inserter tool is also provided and it can be configured to couple to the sheath and to advance the expandable sheath, with a tendon disposed therearound, into a bone hole. An expander is also provided for expanding the sheath. In this way, a tendon or ligament is delivered into the bone hole and the sheath and tendon are locked within the bone hole.
