Device for installing an anchor in a bone

#This invention generally relates to surgically installing an anchor in a bone of a patient, and more particularly, to an improved device that allows for quick and easy installation of an anchor in the bone.

#Suture anchors are used to secure sutures to bones during joint reconstructive surgery or arthroscopic surgical procedures. The anchor allows a suture to be secured to it, whereas it would otherwise be difficult to secure the suture to the bone material. For example, suture anchors are used to connect ligaments or tendons to bones during knee, shoulder or elbow reconstruction or repair operations. A bone anchor must be easy to install and must remain firmly in place for the intended time. It must be able to resist withdrawal forces exerted by the attached suture, and must also be physically compatible with the bone structure and other body tissues.

#U.S. Pat. No. 4,738,255 disclosed a suture anchor having a collar with a slotted end that expands when a plug or ram is pulled into the distal end of the collar. The ram is pulled into the slotted collar by tension exerted on a line that runs axially through a mandrel from which the collar is suspended.

#FIG. 1 illustrates an anchor device in accordance with the present invention and the manner of installing the device in a bone of a patient.

#FIG. 2 is a perspective diagram showing an anchor body with tapered side walls, upper anchor plate, external deformation wrinkle, and conical expansion member inside thereof

#FIG. 3 is a diagram of one embodiment of the conical expansion member having recesses formed on the underside thereof for engagement with an expansion tool of the scissors-type.

#Referring to FIG. 1, a device for surgically installing an anchor in bone includes an anchor body 10, an expansion member 11, and an installation tool 12. The anchor body 10 is installed in a patient's bone as a terminal for fixation of fractures or joints or to repair or attach tendons or ligaments to the bone. An incision 13 is first made through the patient's skin (SKIN) or tissue to expose the work area of the bone (BONE). A borehole 15 is drilled into the bone for installation of the anchor body 10 therein. The anchor body 10 has expandable side walls with a tapered shape, with a narrower proximal end thereof(toward the top of the figure) to face outwardly from the borehole in the bone and a wider distal end thereof (toward the bottom of the figure) to be inserted in the borehole. The anchor body 10 may have an upper anchor plate 10a that overlies or is adhered with an adhesive layer 14 over the borehole in order to positively locate the anchor unit aligned with the surface of the bone. The expansion member 11 has a tapered shape and is positioned in the interior space within the side walls of the anchor body 10. It is used to expand the side walls of the anchor body outwardly in order to engage retention members 16 with the borehole walls to inhibit retraction from the bone (to be explained in further detail below).

#The expansion tool 12 has a handle with a trigger for operation and a long stem or probe with a distal end for insertion through an aperture in the proximal end of the anchor body 10 to grasp or engage the expansion member 11. In the embodiment shown, the tool 12 is of the scissors-type with a pair of movable prongs or tabs 12b that can be scissored to fold together in overlapped fashion (when the trigger of the tool is pulled) to allow the probe end to be inserted through the aperture in the anchor body, and released to extend outwardly (when the trigger of the tool is released) to engage in tab recesses 17 formed on the underside of the expansion member. The expansion tool 12 is used to pull the expansion member 11 from the disengaged position toward the distal end of the anchor body to the engaged position toward the proximal end of the anchor body (in the direction of the vertically pointing arrows), in order to expand the side walls (in the direction of the laterally pointing arrows) for pressing retention members 16 against the borehole walls.

#The expansion tool can be formed as a surgical, stainless steel instrument, approximately 8 to 10 inches long, with a pistol grip handle and trigger that will allow gripping of all four fingers against the thumb and thenar eminence to apply significant pressure. As an alternative to the scissors-type with movable tab ends, the tool can have a long thin stem with a threaded tip that engages with a threaded bore formed in the expansion member. The trigger can be used to activate a small battery-powered rotary drive motor for rotating the stem to thread the tip into the threaded bore to engage the expansion member, and reversed to thread the tip out of the bore to release the tool from the expansion member.