Methods and systems are provided for securing tissue to bone. A surgical system can include an outer shaft, an elongate inner shaft, and an implantable suture anchor assembly including first and second anchor bodies. The second, more proximal, anchor body has one or more openings extending through a side wall or through opposed side walls thereof. The inner shaft is configured to be received within the outer shaft and through the first and second anchor bodies such that a distal end of the inner shaft protrudes beyond a distal end of the first anchor body. The inner shaft is configured to be removably coupled to the first anchor body such that the inner shaft is configured to be rotated to cause a proximal portion of the first anchor body to move proximally into a lumen extending through the second anchor body and to occlude the opening in the second anchor body.