Methods and prostheses for stabilizing bone structures
Methods are described for stabilizing dysfunctional bone structures. The methods include the step of providing prostheses having an elongated body with dual, i.e., first and second, threaded ends and an intervening central region. The threaded ends have helical threads wound thereon that extend from the intervening central region to the ends of the first and second threaded ends. The methods further include the steps of creating a pilot opening in the dysfunctional bone structures and inserting the prostheses into the pilot opening and, thereby dysfunctional bone structure.
1 . A method for stabilizing a dysfunctional bone structure of a subject, comprising the steps of:
providing a bone structure prosthesis, said bone structure prosthesis comprising an elongated threaded member adapted to threadably engage bone structures, said elongated threaded member comprising a monolithic structure,
said elongated threaded member further comprising a first self-tapping threaded end region, a second self-tapping threaded end region, and an intervening non-threaded central region that is disposed between said first self-tapping threaded end region and said second self-tapping threaded end region,
said elongated threaded member further comprising a proximal tapered end region and a distal tapered end region, said distal tapered end region comprising a closed configuration,
said first self-tapping threaded end region comprising a first proximal end and a first distal end,
said first self-tapping threaded end region further comprising a first helical thread, said first helical thread extending from said first distal end to said first proximal end of said first self-tapping threaded end region in a first direction,
said second self-tapping threaded end region comprising a second proximal end and a second distal end,
said second self-tapping threaded end region comprising a second helical thread, said second helical thread extending from said second proximal end to said second distal end of said second self-tapping threaded end region in a second direction,
said first direction of said first helical thread being opposite said second direction of said second helical thread, wherein said first helical thread and said second helical thread comprise reverse orientations,
whereby, when said dysfunctional bone structure comprises a first bone segment and a second bone segment, said first self-tapping threaded end region of said elongated threaded member is inserted into said first bone segment, said second self-tapping threaded end region of said elongated threaded member is inserted into said second bone segment, and said elongated threaded member is rotated in a first direction, said first self-tapping threaded end region advances into said first bone segment and said second self-tapping threaded end region advances into said second bone segment, wherein said first and second self-tapping threaded end regions jointly provide a coupling force between said first and second bone segments,
said elongated threaded member further comprising an internal lumen that extends longitudinally through said elongated threaded member from said proximal tapered end region to said distal tapered end region of said elongated threaded member,
said elongated threaded member further comprising an osteogenic composition, said osteogenic composition disposed in said internal lumen,
said non-threaded central region of said elongated threaded member comprising a plurality of slits that extends from a first exterior surface of said non-threaded central region to said internal lumen, said plurality of slits adapted to allow said osteogenic composition to be dispersed out of said internal lumen and into and though said plurality of slits, and delivered to said dysfunctional bone structure when said elongated threaded member is engaged thereto,
said first self-tapping threaded end region of said elongated threaded member comprising a first plurality of apertures in communication with said internal lumen, said first plurality of apertures configured and adapted to allow said osteogenic composition to be dispersed out of said internal lumen and into and through said first plurality of apertures, and delivered to said dysfunctional bone structure when said elongated threaded member is threadably engaged thereto,
said second self-tapping threaded end region of said elongated threaded member comprising a second plurality of apertures in communication with said internal lumen, said second plurality of apertures configured and adapted to allow said osteogenic composition to be dispersed out of said internal lumen and into and through said second plurality of apertures, and delivered to said dysfunctional bone structure when said elongated threaded member is threadably engaged thereto;
positioning said elongated threaded member between said first and second bone segments of said dysfunctional bone structure, wherein said proximal tapered end region of said elongated threaded member is in contact with said first bone segment of said dysfunctional bone structure and said distal tapered end region of said elongated threaded member is in contact with said second bone segment of said dysfunctional bone structure; and
rotating said elongated threaded member in said first direction, wherein said first self-tapping threaded end region of said elongated threaded member advances into said first bone segment and said second self-tapping threaded end region of said elongated threaded member advances into said second bone segment, whereby said first and second self-tapping threaded end regions said jointly provide said coupling force between said first and second bone segments.
2 . The method of claim 1 , wherein said osteogenic composition comprises a bone morphogenic protein (BMP) selected from the group consisting of BMP-1, BMP2a, BMP2b, BMP3, BMP4, BMP5, BMP6, BMP7, and BMP8a.
3 . The method of claim 1 , wherein said osteogenic composition comprises an antibiotic selected from the group consisting of penicillin, a carboxypenicillin, a tetracycline, gentamicin, vancomycin, ciprofloxacin, amikacin, an aminoglycoside, a cephalosporin, clindamycin, erythromycin, a fluoroquinolone, a macrolide, an azolide, metronidazole, trimethoprim-sulfamethoxazole, polymyxin B, oxytetracycline, tobramycin, cefazolin, and rifampin.
4 . The method of claim 1 , wherein said osteogenic composition comprises an anti-inflammatory selected from the group consisting of dexamethasone, betamethasone, prednisone, prednisolone, methylprednisolone sodium succinate, methylprednisolone, cortisone, ketorolac, diclofenac, and ibuprofen.
5 . The method of claim 1 , wherein said osteogenic composition comprises a biologically active agent.
6 . The method of claim 5 , wherein said biologically active agent comprises a cell selected from the group consisting of a human embryonic stem cell, mesenchymal stem cell, hematopoietic stem cell, bone marrow-derived progenitor cell, bone marrow stromal cell (BMSCs), osteoprogenitor cell, osteoblast, osteocyte, and osteoclast.
7 . The method of claim 5 , wherein said biologically active agent comprises a growth factor selected from the group consisting of a transforming growth factor-alpha (TGF-α), transforming growth factor-beta (TGF-β), fibroblast growth factor-2 (FGF-2), and vascular endothelial growth factor (VEGF).
8 . The method of claim 1 , wherein said elongated threaded member comprises a biodegradable material selected from the group consisting of magnesium, a magnesium-aluminum (Mg—Al) alloy, magnesium-rare earth alloy, magnesium-zinc (Mg—Zn) alloy, magnesium-calcium (Mg—Ca) alloy, and zinc-based alloy.
9 . The method of claim 1 , wherein said elongated threaded member comprises an outer coating.
10 . The method of claim 9 , wherein said outer coating comprises a poly(glycerol sebacate) (PGS)-based coating.