Intramedullary fixation assembly and devices and methods for installing the same

Abstract

An intramedullary fixation assembly usable with different long bone types and a guide assembly for guiding deployment of the intramedullary fixation assembly. The intramedullary fixation assembly includes a fixation member that has ends and a curved body extending between the ends. The curved body of the fixation member has a radius of curvature configured to extend through the medullary canal regardless of the long bone anatomy. Fasteners fix the fixation member to the bone fragments and are guided by a guide assembly. The guide assembly includes a guide body defining openings configured to guide the fasteners through openings defined in the fixation member and into the bone fragments. A fixation end of the guide body includes a pair of opposing, converging surfaces that are configured to engage in a positive fit with an exposed end of the fixation member accessible through the side aperture in the first fragment.

1 . An intramedullary fixation member for use in repairing a distal radius bone fracture, the distal radius having an articular surface, comprising: 
 an elongate fixation member sized for insertion into the medullary canal of the radius, the fixation member being curved between a first end and a second end, the second end adapted for placement within the medullary canal distal from the articular surface of the distal radius;    a convex surface and an opposing concave surface extending between the first end and the second end of the fixation member;    opposing side surfaces extending between the convex surface and the opposing concave surface;    a first pair of fastener openings extending through the fixation member, wherein the first pair of fastener openings are oriented at different angles;    a second pair of fastener openings extending through the fixation member distal to the first pair of fastener openings; and    a guide attachment surface adjacent to the concave surface at the first end of the elongate fixation member and configured for forming a positive fit between the guide attachment surface and a mating surface of a guide assembly adapted for guiding placement and fixation of the elongate fixation member in the medullary canal.    
   
   
       2 . The intramedullary fixation member of  claim 1 , wherein the guide attachment surface defines one or more indentations or prongs adapted for forming a positive fit with the mating surface of the guide assembly.  
   
   
       3 . The intramedullary fixation member of  claim 1 , wherein the convex surface and the opposing concave surface curve continuously between the first end and the second end of the elongate fixation member.  
   
   
       4 . An intramedullary fixation member for use in repairing a distal radius bone fracture, the distal radius having an articular surface, comprising: 
 an elongate fixation member sized for insertion into the medullary canal of the distal radius, the fixation member being curved between a first end and a second end, the second end adapted for placement within the medullary canal distal from the articular surface of the distal radius;    a convex surface and an opposing concave surface extending between the first end and the second end of the fixation member;    opposing side surfaces extending between the convex surface and the opposing concave surface;    a first fastener opening extending through the fixation member between the convex surface and the opposing concave surface;    a second fastener opening extending through the fixation member between the opposing side surfaces;    a guide attachment surface adjacent to the concave surface at the first end of the elongate fixation member and configured for forming a positive fit between the guide attachment surface and a mating surface of a guide assembly adapted for guiding placement and fixation of the fixation member in the medullary canal; and    a third fastener opening extending through the fixation member between the guide attachment surface and the convex surface.    
   
   
       5 . The intramedullary fixation member of  claim 4 , wherein the guide attachment surface defines one or more indentations or prongs adapted for forming a positive fit with the mating surface of the guide assembly.  
   
   
       6 . The intramedullary fixation member of  claim 5 , wherein the guide attachment surface defines one or more indentations adapted for forming a positive fit with one or more prongs extending from the mating surface of the guide assembly.  
   
   
       7 . The intramedullary fixation member of  claim 6 , wherein the guide attachment surface defines a plurality of indentations for forming a positive fit with a plurality of prongs extending from the mating surface of the guide assembly, wherein the plurality of indentations are in a cruciform pattern.  
   
   
       8 . The intramedullary fixation member of  claim 4 , wherein the guide attachment surface and the mating surface of the guide assembly each define an S-curved fitting adapted for forming a positive fit between the guide attachment surface and the mating surface.  
   
   
       9 . The intramedullary fixation member of  claim 4 , wherein the convex surface and the opposing concave surface are tapered between the first end and the second end of the elongate fixation member, and wherein the opposing side surfaces are tapered between the first end and the second end of the elongate fixation member.  
   
   
       10 . The intramedullary fixation member of  claim 4 , wherein the convex surface and the opposing concave surface curve continuously between the first end and the second end of the elongate fixation member.  
   
   
       11 . The intramedullary fixation member of  claim 4 , wherein the radius of curvature of the convex surface and opposing concave surface is in the range of 1.5 to 5 inches.  
   
   
       12 . The intramedullary fixation member of  claim 4 , wherein the guide attachment surface is a flat surface.  
   
   
       13 . The intramedullary fixation member of  claim 4 , comprising a pair of first fastener openings extending through the fixation member between the convex surface and the opposing concave surface oriented at different, divergent angles.  
   
   
       14 . The intramedullary fixation member of  claim 13 , wherein at least one of the first fastener openings extends at an angle matching the inclination angle of the articular surface of the distal radius.  
   
   
       15 . The intramedullary fixation member of  claim 4 , comprising a pair of first fastener openings extending through the fixation member between the convex surface and the opposing concave surface and proximal to the first end of the elongate fixation member, and a pair of second fastener openings extending through the fixation member between the opposing side surfaces and distal from the first pair of fastener openings.  
   
   
       16 . The intramedullary fixation member of  claim 4 , further comprising at least one k-wire sized guide opening extending through the fixation member between the opposing side surfaces.  
   
   
       17 . The intramedullary fixation member of  claim 4 , wherein the third fastener opening comprises a first portion adjacent to the guide attachment surface and a second portion adjacent to the convex surface, wherein the second portion is narrower than the first portion.  
   
   
       18 . The intramedullary fixation member of  claim 17 , wherein both the first portion and the second portion are threaded.  
   
   
       19 . The intramedullary fixation member of  claim 4 , further comprising a flat surface adjacent and perpendicular to the guide attachment surface, and configured to underlie the articular cartilage when placed in the medullary canal of the distal radius.  
   
   
       20 . The intramedullary fixation member of  claim 4 , wherein the guide attachment surface defines a plurality of indentations adapted for forming a positive fit with a plurality of prongs extending from the mating surface of the guide assembly, and wherein the plurality of indentations are spaced around the third fastener opening.  
   
   
       21 . An intramedullary fixation member for use in repairing a distal radius bone fracture, the distal radius having an articular surface, comprising: 
 an elongate fixation member sized for insertion into the medullary canal of the distal radius, the fixation member being curved between a first end and a second end, the second end adapted for placement within the medullary canal distal from the articular surface of the distal radius;    a convex surface and an opposing concave surface extending between the first end and the second end of the fixation member, the convex and concave surfaces being tapered between the first end and the second end of the fixation member;    opposing side surfaces extending between the convex surface and the opposing concave surface;    a first pair of fastener openings extending through the fixation member between the convex surface and the opposing concave surface proximal to the first end of the elongate fixation member, wherein the first pair of fastener openings are oriented at different, divergent angles;    a second pair of fastener openings extending through the fixation member between the opposing side surfaces and distal to the first pair of fastener openings;    a guide attachment surface adjacent to the concave surface at the first end of the elongate fixation member, wherein the guide attachment surface defines a plurality of indentations adapted for forming a positive fit with a plurality of prongs extending from a mating surface of a guide assembly adapted for guiding placement and fixation of the fixation member in the medullary canal; and    a third fastener opening extending through the fixation member between the guide attachment surface and the convex surface, the plurality of indentations being spaced around the third fastener opening.    
   
   
       22 . The intramedullary fixation member of  claim 21 , wherein at least one of the first pair of fastener openings extends at an angle matching the inclination angle of the articular surface of the distal radius.  
   
   
       23 . The intramedullary fixation member of  claim 21 , further comprising at least one k-wire sized guide opening extending through the fixation member between the opposing side surfaces.  
   
   
       24 . The intramedullary fixation member of  claim 21 , wherein the third fastener opening comprises a first portion adjacent to the guide attachment surface and a second portion adjacent to the convex surface, wherein the second portion is narrower than the first portion and both the first portion and the second portion are threaded.  
   
   
       25 . An intramedullary fixation member for use in repairing a distal radius bone fracture, the distal radius having an articular surface, comprising: 
 an elongate fixation member sized for insertion into the medullary canal of the distal radius, the fixation member being curved between a first end and a rounded second end, the second end adapted for placement within the medullary canal distal from the articular surface of the distal radius;    a convex surface and an opposing concave surface extending between the first end and the second end of the fixation member, the convex and concave surfaces being tapered between the first end and the second end of the fixation member;    opposing side surfaces extending between the convex surface and the opposing concave surface;    a first pair of fastener openings extending through the fixation member between the convex surface and the opposing concave surface proximal to the first end of the elongate fixation member, wherein the first pair of fastener openings are oriented at different, divergent angles, and wherein at least one of the first pair of fastener openings extends at an angle matching the inclination angle of the articular surface of the distal radius;    a second pair of fastener openings extending through the fixation member between the opposing side surfaces and distal to the first pair of fastener openings;    at least one k-wire sized guide opening extending through the fixation member between the opposing side surfaces;    a guide attachment surface adjacent to the concave surface at the first end of the elongate fixation member, wherein the guide attachment surface defines a plurality of indentations adapted for forming a positive fit with a plurality of prongs extending from a mating surface of a guide assembly adapted for guiding placement and fixation of the fixation member in the medullary canal; and    a third fastener opening extending through the fixation member between the guide attachment surface and the convex surface, the plurality of indentations being spaced around the third fastener opening, wherein the third fastener opening comprises a first portion adjacent to the guide attachment surface and a second portion adjacent to the convex surface, the second portion being narrower than the first portion and both portions being threaded.