Intramedullary rod apparatus and methods of repairing proximal humerus fractures

Abstract

A bone stabilizing apparatus includes a stem member and an extension member, the stem member having a distal end for insertion within the intramedullary canal of a human humerus and the proximal end connected to the extension member. The extension member has radially directed threaded holes either pre-formed or created after the bone stabilizing apparatus is installed into the humerus. The threaded holes allow fixation of stabilizing screws with suture posts, or a washer structure to grip the surface of the bone and/or surrounding ligaments or muscle. A prosthetic or the natural humeral head can be attached to the extension member. In a preferred embodiment a guide structure directs the drill and stabilizing screws radially through the central axis of the extension member.

1. A bone stabilizing device, comprising:
 a stem member, extending substantially along a first longitudinal axis, for insertion into a medullary bone cavity, said stem member having a distal end and a proximal end; 
 ana substantially cylindrical extension member positioned substantially outside of the medullary bone cavity, extending substantially along a second longitudinal axis, having a distal and a proximal end, said distal end connected to said proximal end of said stem member; and 
 means for securing a fractured metaphyseal or epiphyseal bone to said extension member comprising a securing member having a first end affixed into mechanically attached to the extension member and a second end spaced apart from said extension member, and means connected to said second end for pressing on a cortical surface of the bone to urge the bone against said extension member, wherein a third longitudinal axis of the securing member is unaligned with the second longitudinal axis of the extension member. 
 
     
     
       2. A bone stabilizing device according to  claim 1  wherein said extension member consisting essentially of a plastic material substantially devoid of a metal casing, and
 said means for securing bone plastic material further includes a threaded hole transversely disposed in and opening out of said extension member, and 
 said securing member includes an attachment screw having a threaded portion at its first end engaged with said threaded hole and having a screw head at its second end spaced apart from said extension member, 
 wherein a rotation of said threaded attachment screw urges said screw head against the bone material and thereby urges the bone material against the extension member. 
 
     
     
       3. A bone stabilizing device according to  claim 2 , further comprising a washer disposed between said screw head and an outer surface of said extension member,
 wherein a rotation of said threaded attachment screw urges said washer against the bone material and thereby urges the bone against the extension member. 
 
     
     
       4. A bone stabilizing device according to  claim 1 , further comprising a positioning means for connecting a bone to said extension member at a predetermined angle. 
     
     
       5. A bone stabilising device according to  claim 4 , wherein said positioning means comprises an angled fixation bracket connected to said extension member, said angled fixation bracket having a support plate for supporting the bone having a plurality of passages formed therethrough; and
 a means for connecting the bone to the support plate through said plurality of passages.   
     
     
       6. A bone stabilizing device according to  claim 4 , wherein said positioning means comprises an angled fixation bracket connected to said extension member, said angled fixation bracket having a support plate for supporting the bone and further comprising a plurality of mounting screws,
 said screws each having a first and second threaded portion, said first portion having a first thread pitch and said second portion having a second thread pitch greater than said first pitch, said screws being arranged such that said first portion is threaded into said bone and said second portion is threaded into said support plate,   whereby a rotation of said mounting screws urges said bone against said support plate.   
     
     
       7. A bone stabilizing device according to  claim 4 , wherein said positioning means comprises:
 an angled fixation bracket connected to said extension member, said angled fixation bracket having a support plate for supporting the bone;   a plurality of cannulated mounting screws each having a head on a first side of said support plate and a threaded portion extending into a bone on a second side of said support plate, said cannulated screws each having a through-bore; and   a suture thread passing through the through-bore of at least two of said cannulated screws and through said bone.   
     
     
       8. A bone stabilizing device according to  claim 7  wherein at least one of said cannulated screws includes a suture tie bar located proximal to the head thereof. 
     
     
       9. A bone stabilizing device according to  claim 4  wherein said positioning means comprises a plurality of rods, each of said rods having:
 a first portion extending through a corresponding lateral clearance hole in said extension member; 
 a threaded portion for threaded engagement into said bone; 
 means for moving said rod axially through said lateral clearance hole; and 
 means for locking said rod to said extension member at a selectable axial position within said clearance hole. 
 
     
     
       10. A bone stabilizing device according to  claim 1 , further comprising:
 a prosthetic humeral head; 
 positioning means for connecting said prosthetic humeral head to said extension member in a predetermined position humeral neck-shaft angle; and 
 means for locking prosthetic humeral head in said position. 
 
     
     
       11. A bone stabilizing device according to  claim 10 , wherein said positioning means are removably connected to at least one of said prosthetic humeral head and said extension member. 
     
     
       12. A bone stabilizing device comprising:
 a stem member, extending substantially along a first longitudinal axis, for insertion into a bone cavity; 
 ana substantially cylindrical extension member, connected to said stem member, said extension member having a plastic material,and extending substantially along a second longitudinal axis; 
 a prosthetic head having a mounting surface and a hemispherical shaped surface formed about a centerline; and 
 means for securing said prosthetic head to said extension member, said means comprising:
 a support member connected to said extension member having a head support surface facing toward said mounting surface of said prosthetic head, said head support surface forming a predetermined angle with said extension member, 
 a hole formed in said support member and projecting into said head support surface toward said extension member, and 
 a pin connected to said mounting surface of said prosthetic head; and 
 
 means for securing a fractured metaphyseal bone to said extension member, said means for securing bone comprising: 
 an attachment screw having a threaded portion engaged with said extension member and having a screw head spaced apart from an outer surface of said extension member, wherein a rotation of said threaded attachment screw urges said screw head against the bone and thereby urges the bone against the extension member. 
 
     
     
       13. A bone stabilizing device comprising:
 a stem member, extending substantially along a first longitudinal axis, for insertion into a bone cavity, said stem member having a distal end and a proximal end; 
 an extension member, extending substantially along a second longitudinal axis, having a distal and a proximal end; 
 a spacer bracket having a mounting flange with a hole formed therein and having a support face; 
 a threaded extension, formed on one of said proximal end of said stem member and said distal end of said extension member, said threaded extension passing through said hole in said mounting flange and threading into a threaded hole formed in the other of said proximal end of said stem member and said distal end of said extension member, so as to securely mount said mounting flange to said extension member and said stem member; 
 a prosthetic head having a substantially planar surface and having a hemispherical shaped surface formed about a centerline extending normal to said planar surface; and 
 means for securing said prosthetic head to said spacer bracket, said means comprising a tapered hole extending normal into a plane of the support face of said spacer bracket and a tapered pin connected to the planar surface of said prosthetic head. 
 
     
     
       14. A bone stabilizing device according to  claim 13 , wherein said extension member includes a plastic material, and further comprising:
 means for securing a bone to said extension member, said means for securing said bone comprising: 
 a screw having a threaded portion engaged with said extension member and having a screw head spaced apart from an outer surface of said extension member, and 
 a washer disposed between said screw head and an outer surface of said extension member, 
 wherein a rotation of said threaded screw urges said washer against the bone and thereby urges the bone against the extension member. 
 
     
     
       15. A bone stabilizing device according to claim 1, wherein the securing member comprises a screw. 
     
     
       16. A bone stabilizing device according to claim 15, wherein the screw comprises a pressure type stabilizing screw, a suture type stabilizing screw, or an anchor with a threaded end and at least one flange at the second end. 
     
     
       17. A bone stabilizing device according to claim 15, wherein the means connected to said second end for pressing on a cortical surface of the bone comprises a head of said screw. 
     
     
       18. A bone stabilizing device according to claim 17, wherein said second end further comprises a washer. 
     
     
       19. A bone stabilizing device according to claim 18, wherein said washer comprises a claw washer. 
     
     
       20. A bone stabilizing device according to claim 19, wherein said claw washer comprises a slot. 
     
     
       21. A bone stabilizing device according to claim 1, wherein a distal tip of said first end of the securing member protrudes from the extension member. 
     
     
       22. A bone stabilizing device according to claim 1, wherein the first longitudinal axis forms an angle with the second longitudinal axis. 
     
     
       23. A bone stabilizing device according to claim 22, wherein the angle is less than 180 degrees. 
     
     
       24. A bone stabilizing device according to claim 1, wherein the securing member comprises at least one screw wherein the first end of the at least one screw is a threaded end, and wherein said means connected to said second end for pressing on a cortical surface of the bone to urge the bone against said extension member comprises at least one flange at the second end; and
 wherein the bone stabilizing device further comprises a second means for securing the bone to said extension member.   
     
     
       25. A bone stabilizing device according to claim 1, wherein said bone is separated from an adjacent bone by a fracture line and said securing member crosses the fracture line to secure said bone to said extension member. 
     
     
       26. A bone stabilizing device according to claim 1, wherein said means for securing a bone to said extension member comprising more than one securing member.