Apparatuses for attaching tissue to bone are provided. In one exemplary embodiment, the apparatus includes an expandable body defining a bore, an expander pin having a shaft sized to be received in the bore of the expandable body, and an insertion shaft slidingly disposed in the bore of the expandable body and in a bore of the expander pin. The body is configured to expand laterally into and attach to bone when the expander pin is driven into the expandable body. The body includes a proximal main member having a distally extending threaded projection and a harder, distal tip member having a threaded recess in a proximal surface thereof such that the projection is threadedly interengageable with the recess. The expansion of the body by way of the expander pin can occur when the proximal main member and distal tip member are threadedly engaged. The insertion shaft is releasably secured to the expandable body and extends distally beyond the expandable body.