Methods, instruments and implants for scapho-lunate reconstruction

Abstract

A method for bone reconstruction includes aligning a first bone with a second bone using a plurality of guidewires to correct rotational deformity of the first and second bones. A first module of a targeting apparatus is positioned in proximity to the first bone. A tip of the first module is engaged with the first bone. A second module of the targeting apparatus is positioned in proximity to the second bone. A tip of the second module is engaged with the second bone. Alignment of the first module and the second module is secured. The alignment is verified using a guidewire, the guidewire wire is inserted through a passage extending through the second module. A length between the first bone and the second bone is determined using a depth gauge. An implant is selected based on the determined length for delivery along the passage extending through the second module.

What is claimed is: 
     
         1 . A three-piece modular implant assembly, comprising:
 a first threaded end section configured and adapted for insertion into a first bone;   a second threaded end section configured and adapted for insertion into a second bone, wherein the first and second bones form a movable anatomical joint; and   an intermediate section operatively connected between the first threaded end section and the second threaded end section, wherein the first threaded end section and the second threaded section are configured to be inserted into the respective bones with a monolithic screwing motion, and wherein after insertion into the first and second bones, the first and second threaded sections rotate independently of each other in concert with the movable anatomical joint.   
     
     
         2 . The three-piece modular implant assembly of  claim 1 , configured such that a driver may engage a proximal or distal end of the implant assembly so that both the first and second threaded end sections are driven at the same time to adjust the insertion of the implant assembly into the respective bones or remove the implant assembly from the respective bones. 
     
     
         3 . The three-piece modular implant assembly of  claim 2 , wherein the driver engages both a drive socket of the first threaded end section and a drive socket of the intermediate section at the same time. 
     
     
         4 . The three-piece modular implant assembly of  claim 1 , wherein the first and second threaded end sections are configured to allow a length of the implant assembly to be adjusted. 
     
     
         5 . The three-piece modular implant assembly of  claim 4 , wherein the intermediate section includes an exteriorly threaded region configured to engage an interiorly threaded region of the second threaded end section. 
     
     
         6 . The three-piece modular implant assembly of  claim 5 , wherein a handedness of the exteriorly threaded region of the intermediate section is opposite of a handedness of the first threaded end section. 
     
     
         7 . The three-piece modular implant assembly of  claim 5 , wherein the engagement of the exteriorly threaded region of the intermediate section and the interiorly threaded region of the second threaded end section allows for adjusting the length of the implant assembly. 
     
     
         8 . The three-piece modular implant assembly of  claim 1 , wherein the first bone is a scaphoid bone and the second bone is a lunate bone. 
     
     
         9 . The three-piece modular implant assembly of  claim 1 , wherein the implant is not cannulated. 
     
     
         10 . The three-piece modular implant assembly of  claim 1 , wherein the first and second threaded end sections are configured to allow rotation and translation between the two ends of the implant assembly post implantation. 
     
     
         11 . The three-piece modular implant assembly of  claim 1 , wherein a core diameter of at least a portion of the first threaded end section is greater than a core diameter of at least a portion of the second threaded end section. 
     
     
         12 . The three-piece modular implant assembly of  claim 1 , wherein a pitch diameter of the first threaded end section is greater than a pitch diameter of the second threaded end section. 
     
     
         13 . The three-piece modular implant assembly of  claim 1 , wherein the implant assembly effects compression across the first and second bones once inserted into the first and second bones. 
     
     
         14 . The three-piece modular implant assembly of  claim 1 , wherein the first threaded end section is welded to the intermediate section. 
     
     
         15 . An implant insertion system comprising:
 a three-piece modular implant assembly including:
 a first threaded end section configured and adapted for insertion into a first bone, 
 a second threaded end section configured and adapted for insertion into a second bone, and 
 an intermediate section operatively connected between the first threaded end section and the second threaded end section, wherein after insertion into the first and second bones, the first and second threaded sections rotate independently of each other; and 
   a medical apparatus to aid in the insertion of the three-piece modular implant assembly, the medical apparatus including:
 a reduction frame, 
 a first module operatively connected to the reduction frame and configured to engage the first bone, and 
 a second module operatively connected to the reduction frame and configured to engage the second bone, wherein the second module includes a passage extending laterally therethrough, the passage being parallel to the reduction frame. 
   
     
     
         16 . The implant insertion system of  claim 15 , wherein the reduction frame includes a depth gauge for determining a needed length for the three-piece modular implant assembly. 
     
     
         17 . The implant insertion system of  claim 15 , wherein the first threaded end section and the second threaded section are configured to be inserted into the respective bones with a monolithic screwing motion. 
     
     
         18 . The implant insertion system of  claim 15 , wherein the first module includes a first tip configured to engage the first bone and the second module includes a second tip configured to engage the second bone. 
     
     
         19 . The implant insertion system of  claim 15 , wherein the three-piece modular implant assembly and the passage of the medical apparatus are configured such that the three-piece module implant assembly may be delivered through the passage. 
     
     
         20 . The implant insertion system of  claim 15 , further comprising a first guidewire, a second guidewire, and a drill.