Apparatus and Method for Use in the Treatment of Hammertoe

Abstract

The apparatus and method is directed to a pair of self-tapping, interconnecting, externally and internally threaded devices that, when installed between two separate pieces of material, will draw and hold the material together as a single threaded unit. While the pair of threaded devices are being fastened into the host material, due to the unique design of their threads, no radial outward forces are produced that could cause cracking or splitting of the sections of the material into which they are installed. The external threads are helically defined into the exterior of each half of the device with a right hand thread defined into one half and a left hand thread into the other half. When the two halves are being fastened together, the increased thread pitch on one of the halves continuously draws the halves into each other even when the internal threads have already been maximally tightened.

1 . An apparatus for coupling at least two pieces of host material together comprising:
 a hollow proximal half with an internal surface and an external surface for implantation into one of the two pieces of the host material;   a hollow distal half with an internal surface and an external surface for implantation into the other one of the two pieces of host material;   and means for threadably engaging the distal half and proximal half together.   
     
     
         2 . The apparatus of  claim 1  where the proximal half and the distal half each comprise a helical external thread the external surface of each respective half for engagement with the two pieces of host material. 
     
     
         3 . The apparatus of  claim 2  where the proximal half and the distal half each comprise at least two opposing self-tapping bores defined through the internal and external surfaces and the external threads of each respective half to act as a repository for the removed debris of the host material. 
     
     
         4 . The apparatus of  claim 2  where the external threads on the proximal half are arranged and configured in the opposite helical sense to that of the external threads on the distal half. 
     
     
         5 . The apparatus of  claim 1  where the means for threadably engaging the distal half and proximal half together comprise: a peg comprising a male threaded portion disposed on a distal end of the proximal half; and a female threaded portion defined on the internal surface of the distal half. 
     
     
         6 . The apparatus of  claim 1  where the proximal half and the distal half both comprise a hexagonally shaped internal bore defined in at least a portion of each respective half. 
     
     
         7 . The apparatus of  claim 1  where the distal half further comprises at least two opposing wrench flats defined on the external surface. 
     
     
         8 . The apparatus of  claim 2  where the external threads on the proximal half are orientated at a different pitch to that of the external threads on the distal half. 
     
     
         9 . The apparatus of  claim 3  where the external threads that have the at least two self-tapping bores defined therethrough comprise sharp, angled open faces to cut into the host material when the proximal half and distal half are rotated. 
     
     
         10 . A method for coupling at least two pieces of host material together with an adjustable device comprising: inserting a proximal half of the device into a proximal one of the two pieces of the host material; inserting a distal half of the device into a distal one of the two pieces of the host material; and coupling the proximal one of the two pieces of the host material to the distal one of the two pieces of the host material by means of the proximal half of the device. 
     
     
         11 . The method of  claim 10  where inserting the proximal half of the device in the proximal one of the two pieces of the host material comprises:
 rotating the proximal half of the device into a predrilled bore; 
 cutting a female thread into the predrilled bore in the host material by means of an external thread disposed around the proximal half of the device; and 
 engaging the female thread cut into the host material by means of the external thread disposed around the proximal half of the device. 
 
     
     
         12 . The method of  claim 10  where inserting the distal half of the device in the distal one of the two pieces of the host material comprises:
 rotating the distal half of the device into a predrilled bore; 
 cutting a female thread into the predrilled bore in the host material by means of an external thread disposed around the distal half of the device; and 
 engaging the female thread cut into the host material by means of the external thread disposed around the distal half of the device. 
 
     
     
         13 . The method of  claim 10  further comprising collecting any debris from the host material in a repository defined into each of the proximal and distal halves of the device when each respective device half is being inserted into its respective one of the two pieces of the host material. 
     
     
         14 . The method of  claim 10  where coupling the proximal portion of the host material to the distal one of the two pieces of the host material by means of the proximal half of the device and the distal half of the device inserted into each respective one of the two pieces of the host material comprises:
 sliding the distal half of the device over a male peg disposed on the distal end of the proximal half of the device; 
 rotating the distal half of the device about the male peg disposed on the distal end of the proximal half of the device; and 
 engaging a female threaded portion defined in an interior surface of the distal half of the device to a male thread portion disposed on the male peg of the proximal half of the device. 
 
     
     
         15 . The method of  claim 14  where rotating the distal half of the device about the male peg disposed on the distal end of the proximal half of the device comprises:
 inserting a hex shaped driving tool into a distal end of the distal half of the device; 
 engaging the hex shaped driving tool in a hexagonally shaped interior bore of the distal half of the device; and 
 rotating the hex shaped driving tool. 
 
     
     
         16 . The method of  claim 10  further comprising adjusting the distance between the proximal one of the two pieces of the host material and the distal one of the two pieces of the host material by means of rotating the distal and proximal halves of the device after they have been joined together. 
     
     
         17 . The method of  claim 16  where rotating the distal half of the device comprises:
 inserting a hex shaped driving tool into a distal end of the distal half of the device; 
 engaging the hex shaped driving tool in a hexagonally shaped interior bore of the distal half of the device; and 
 rotating the hex shaped driving tool. 
 
     
     
         18 . A method for coupling at least two pieces of host material together with an adjustable device comprising:
 inserting a proximal half of the device into a proximal one of the two pieces of the host material;   inserting a distal half of the device into a distal one of the two pieces of the host material;   coupling the proximal one of the two pieces of the host material to the distal one of the two pieces of the host material by means of the proximal half of the device and the distal half of the device which has been inserted into each respective one of the two pieces of the host material;   collecting any debris from the host material in a repository defined into each of the proximal and distal halves of the device when each respective device half is being inserted into its respective one of the two pieces of the host material; and   adjusting the distance between the proximal one of the two pieces of the host material and the distal one of the two pieces of the host material by means of rotating the distal half of the device after it has been jointed to the proximal half of the device.   
     
     
         19 . The method of  claim 18  where inserting the proximal half of the device in the proximal one to the two pieces of the host material and inserting the distal half of the device in the distal one to the two pieces of the host material comprises:
 rotating each of the proximal and distal halves of the device; 
 cutting a female thread into each respective one to the two pieces of the host material by means of an external thread disposed around each of the proximal and distal halves of the device; 
 and engaging the female thread in the host material by means of the external thread disposed around each of the proximal and distal halves of the device. 
 
     
     
         20 . The method of  claim 19  where the rotating of each of the proximal and distal halves of the device comprises:
 inserting a hex shaped driving tool into each of the distal ends of the distal and proximal halves of the device respectively; 
 engaging each hex shaped driving tool in a hexagonally shaped interior bore in each of the distal and proximal halves of the device respectively; and 
 rotating each hex shaped driving tool.