Distal interphalangeal fusion method and device

Abstract

The various embodiments of the present invention provide a system, including methods, apparatus and kits for connecting bones and/or bone portions using a multi-part bone connector with one or more rotating joints.

1 . A method of fusing two adjacent bones to create a non-linear post-fusion orientation comprising:
 (a) providing a bone fusion apparatus comprising:
 (i) an anchor portion having an elongated body with screws threads on at least a portion of its exterior, the anchor having a leading tip and an end; 
 (ii) a compressor portion having an elongated body with screw threads of the same pitch and diameter on at least a portion of its exterior; and 
 (iii) a coupler having a first end adapted to rotatably engage the anchor in a first plane, the coupler also having a second end adapted to rotatably engage the compressor through axial rotation; 
   (b) optionally preparing a channel in the adjacent bones through which the bone fusion apparatus is installed;   (c) inserting the bone fusion apparatus through both bones while positioning the anchor-coupler interface at or near the natural joint location;   (d) flexing the coupler-anchor interface to the desired degree of flexation; and   (e) compressing the adjacent bones by reversing the rotation of the compressor portion sufficiently to impart the desired amount of compression while maintaining the desired alignment of the adjacent bones.   
     
     
         2 . A method of maintaining screw thread synchronization of a bone fusion apparatus having a discontinuous thread, the apparatus having a first screw thread on a leading component and a second screw thread on a trailing component, the two components being separated by a coupling non-threaded component, the screw threads having the same thread pitch, comprising providing separate driving patterns in the trailing and non-threaded component to coordinate the separate screw threads with each other such that a single driving tool having separate complementary driving patterns will facilitate coordination of the screw threads by synchronized alignment and rotation of the trailing and non-threaded components. 
     
     
         3 . A bone fusion apparatus comprising:
 (a) an anchor portion comprising an elongated body with screw threads on at least a portion of its exterior, the anchor having a leading tip and a trailing end adapted for an axial rotation interface, the anchor trailing end also having a keyed driving pattern;   (b) a compressor portion comprising an elongated body with screw threads of the same pitch and diameter on at least a portion of its exterior, the compressor having a trailing end and a leading end adapted for an axial rotation interface, the compressor trailing end also having a keyed driving pattern different from the anchor trailing end keyed driving pattern; and   (c) an interface between compressor portion and anchor portion whereby either the anchor trailing end or the compressor leading end fit within the other longitudinally at a predetermined distance to allow axial rotation and longitudinal immobility.   
     
     
         4 . The apparatus of  claim 3  wherein the anchor trailing end has an external diameter less than the compressor leading end internal diameter. 
     
     
         5 . The apparatus of  claim 3  wherein the anchor trailing end comprises one or more annular ridges. 
     
     
         6 . The apparatus of  claim 5  wherein the compressor leading end comprises one or more annular grooves adapted to fit the one or more annular ridges and allow axial rotation. 
     
     
         7 . The apparatus of  claim 3  wherein the interface comprises a snap-fit type interface. 
     
     
         8 . The apparatus of  claim 7  wherein the snap-fit interface has at least one expansion slot cut through either the compressor body or the anchor body. 
     
     
         9 . A method of locking the configuration of the anchor and coupler of  claim 3  by reversing the axial rotation of the compressor until the bones or bone fragments touch.