Orthopaedic Implant Fixation Using an In-situ Formed Anchor

Abstract

An orthopaedic implant fixation using a surgically created bone cavity as a mold for forming an anchor from an in-situ hardenable material. An in-situ formed anchor of the present invention is especially useful for attaching an implant to osteoporotic cancellous bone. The injectable nature of the in-situ formed anchor allows implants to be adapted to minimally invasive surgical techniques. The present invention can be adapted to numerous implants or implant system components to include fasteners, pins, nails, intramedullary nails, and suture anchors. Applications include bone fracture fixation, bone fracture prevention, and soft-tissue repair.

1 - 6 . (canceled) 
     
     
         7 . An orthopaedic system comprising:
 a pilot hole and entry in a tissue, wherein the entry provides for the pilot hole, the pilot hole having a first diameter, wherein the tissue comprises musculoskeletal tissue;   a cavity in communication with the pilot hole, the cavity having a cavity boundary and a second diameter larger than the first diameter of the pilot hole, wherein the cavity is positioned distal to the pilot hole;   a preformed element positioned at least partially within the cavity, the preformed element comprising:
 a shank having a diameter, a length, a proximal portion, and one or more interlocking elements associated with a distal portion of the shank, wherein the length of the shank is sized so that the distal portion remains within the cavity and the one or more interlocking elements are in contact with a hardenable material in a hardened state, wherein there is a substantial space between the one or more interlocking elements and a portion of the cavity boundary; 
   
       and
 an in-situ formed anchor within the cavity, the in-situ formed anchor comprising:
 the hardenable material at least partially within the cavity and interlocking with the one or more interlocking elements, wherein the in-situ formed anchor has a third diameter substantially larger than the diameter of the preformed element and substantially larger than the first diameter of the pilot hole. 
 
 
     
     
         8 . The system of  claim 7 , wherein the hardenable material is injectable. 
     
     
         9 . The system of  claim 7 , wherein the hardenable material is selected from the group consisting of bone cement, polymethylmethacrylate-based bone cement, load-bearing polymer, synthetic bone substitute, thermoplastic, thermosetting polymer and combinations thereof. 
     
     
         10 . The system of  claim 7 , wherein the preformed element is rigid and made of material selected from the group consisting of one or more metals, polymers, ceramics, and composites. 
     
     
         11 . The system of  claim 7 , wherein the one or more interlocking elements are selected from the group consisting of surface treatments, flanges, serrations, screw threads, holes, slots, grooves, flutes, dimples, and combinations thereof. 
     
     
         12 . The system of  claim 7 , wherein the system is one of the group selected from a compression hip system, intramedullary nail system, suture anchor, and combinations thereof. 
     
     
         13 . The system of  claim 7 , wherein the system stabilizes fractures. 
     
     
         14 . The system of  claim 7 , wherein at least a portion of the cavity boundary is soft musculoskeletal tissue. 
     
     
         15 . The system of  claim 7 , wherein at least a portion of the cavity boundary is bone. 
     
     
         16 . The system of  claim 7 , wherein the one or more interlocking elements are selected from the group consisting of apertures, surface treatments, flanges, serrations, cannulated bone screws, non-cannulated bone screws, screw threads, holes, slots, grooves, flutes, dimples. 
     
     
         17 . The system of  claim 7 , wherein the hardenable material is in a flowable state. 
     
     
         18 . The system of  claim 7 , wherein the hardenable material is in a hardened state. 
     
     
         19 . An orthopaedic system comprising:
 a pilot hole in musculoskeletal tissue having a pilot hole entry, the pilot hole further comprising a first diameter;   a cavity in the musculoskeletal tissue, wherein the cavity is in direct communication with the pilot hole, the cavity having a boundary and a diameter larger than the first diameter of the pilot hole, wherein the cavity is distal to the pilot hole entry;   an in-situ anchor formed from one or more injectable hardenable materials, wherein the one or more injectable hardenable materials are in contact with one or more interlocking elements for interlocking the in-situ anchor with a preformed element, wherein the in-situ anchor has a diameter substantially larger than the first diameter of the pilot hole; and   a preformed element comprising:
 a body having a proximal portion and a distal portion, wherein the distal portion has the one or more interlocking elements adapted for flow of the one or more injectable hardenable materials, wherein at least the distal portion of the body is positioned within the cavity such that there is substantial space between the one or more interlocking elements and the boundary of the cavity. 
   
     
     
         20 . The system of  claim 19 , wherein the one or more injectable hardenable materials are selected from the group consisting of bone cement, polymethylmethacrylate-based bone cement, load-bearing polymer, synthetic bone substitute, thermoplastic, thermosetting polymer and combinations thereof. 
     
     
         21 . The system of  claim 19 , wherein the preformed element is rigid and made of material selected from the group consisting of one or more metals, polymers, ceramics, and composites. 
     
     
         22 . The system of  claim 19 , wherein the one or more interlocking elements are selected from the group consisting of surface treatments, flanges, serrations, screw threads, holes, slots, grooves, flutes, dimples, and combinations thereof. 
     
     
         23 . The system of  claim 19 , wherein the system is one of the group selected from a compression hip system, intramedullary nail system, suture anchor, and combinations thereof. 
     
     
         24 . The system of  claim 19 , wherein the system stabilizes fractures. 
     
     
         25 . The system of  claim 19 , wherein at least a portion of the cavity boundary is soft musculoskeletal tissue. 
     
     
         26 . The system of  claim 19 , wherein at least a portion of the cavity boundary is bone. 
     
     
         27 . The system of  claim 19 , wherein the one or more interlocking elements are selected from the group consisting of apertures, surface treatments, flanges, serrations, cannulated bone screws, non-cannulated bone screws, screw threads, holes, slots, grooves, flutes, dimples. 
     
     
         28 . The system of  claim 19 , wherein the injectable hardenable material is in a flowable state. 
     
     
         29 . The system of  claim 19 , wherein the injectable hardenable material is in a hardened state. 
     
     
         30 . The system of  claim 19 , wherein the preformed element is partially within the cavity.