A suture anchor, and a surgical filament assembly using same, capable of being fixated in a hole formed in a bone of a patient. The suture anchor preferably includes an anchor body with a passage extending from a proximal end toward a distal end, and at least one bone engaging feature on the exterior of the anchor. A knot patency element disposed within the passage holds a removable sliding knot formed, using the surgical filament. A tightening limb of the sliding knot enables the user to tighten the sliding knot against an object extending through a capture loop to secure the object to the anchor.