Bone fixation tensioning tool and method

Abstract

A tensioning tool and method for tensioning a conformable ligature of a bone fixing system are disclosed. The ends of a conformable ligature can be passed around bones, bone grafts, tendons, plates, rods, fasteners, or other anatomical or implanted structures, and the like to form a loop. Another portion of the conformable ligature can be coupled to a tensioning tool. The tensioning tool can include a first portion and a second portion in threaded engagement with each other. Rotation of one portion relative to the other can cause tensioning of the conformable ligature through translation of a tensioning member.

1 . A tensioning tool providing continuous control of conformable ligature tension, comprising:
 a tool body defining a slot;   a connection portion shaped to at least abut a ligature capturing element;   a threaded drive shaft running through at least a portion of the tool body;   a carriage movable along the slot, the carriage defining a drive shaft passage having at least one thread engaging portion to engage threads on the drive shaft and wherein the drive shaft passes through the drive shaft passage; and   a tensioning member coupled to the carriage;   wherein the carriage is configured to be rotated from a first position in which the at least one thread engaging portion is engaged with threads on the drive shaft to a second, slidable position, in which the at least one thread engaging portion is not engaged with the threads of the drive shaft;   wherein rotation of the drive shaft causes the carriage to move towards or away from the connection portion.   
     
     
         2 . The tensioning tool of  claim 1 , further comprising:
 a drive shaft seat in which a first end of the drive shaft is seated;   a spring that compresses between the drive shaft seat and the tool body, wherein the first end is an end proximate the connection portion.   
     
     
         3 . The tensioning tool of  claim 2 , further comprising:
 one or more markings on the tool body that indicate an amount of compression of the spring.   
     
     
         4 . The tensioning tool of  claim 1 , further comprising:
 a detachable handle connected to the drive shaft proximate to a second end that is distal from the first end.   
     
     
         5 . The tensioning tool of  claim 1 , wherein the drive shaft passage includes a first thread engaging portion at a first end of the drive shaft passage, a second thread engaging portion at a second end of the drive shaft passage, and a non-threaded portion positioned between the first thread engaging portion and the second thread engaging portion. 
     
     
         6 . The tensioning tool of  claim 5 , wherein the first thread engaging portion and the second thread engaging portion are located on opposing sides of the drive shaft passage. 
     
     
         7 . The tensioning tool of  claim 1 , wherein the tensioning member is a post extending from the carriage. 
     
     
         8 . The tensioning tool of  claim 7 , wherein the post is configured to receive a loop of a conformable ligature therearound. 
     
     
         9 . The tensioning tool of  claim 1 , wherein the tool body extends through the carriage with a portion of the carriage including the drive shaft passage extending into the slot for receiving the drive shaft therethrough. 
     
     
         10 . A tensioning tool for applying tension to a conformable ligature of a bone fixing system, the tension tool comprising:
 an elongate tool body having a first end and a second end;   a threaded drive shaft extending along at least a portion of the tool body;   a connection portion positioned at the second end of the elongate tool body shaped to engage a ligature capturing element of the bone fixing system; and   a carriage movable along the elongate tool body to selectively apply tension to the conformable ligature via movement of the carriage;   the carriage defining a drive shaft passage through which the drive shaft extends through, the drive shaft passage having at least one thread engaging portion configured to engage threads on the drive shaft;   wherein the carriage is configured to be actuated between a first position and a second position; and   wherein in the first position the at least one thread engaging portion is engaged with threads on the drive shaft such that rotation of the drive shaft causes the carriage to move along the elongate tool body, and in the second position the at least one thread engaging portion is not engaged with the threads of the drive shaft such that the carriage is freely movable along the elongate tool body without rotation of drive shaft.   
     
     
         11 . The tensioning tool of  claim 10 , wherein the drive shaft passage includes a first thread engaging portion at a first end of the drive shaft passage, a second thread engaging portion at a second end of the drive shaft passage, and a non-threaded portion positioned between the first thread engaging portion and the second thread engaging portion. 
     
     
         12 . The tensioning tool of  claim 11 , wherein the first thread engaging portion and the second thread engaging portion are located on opposing sides of the drive shaft passage. 
     
     
         13 . The tensioning tool of  claim 10 , further comprising a tensioning member extending from the carriage configured to receive a loop of a conformable ligature therearound. 
     
     
         14 . The tensioning tool of  claim 10 , wherein the carriage is actuated between the first position and the second position by rotating the carriage about an axis generally perpendicular to a longitudinal axis of the drive shaft. 
     
     
         15 . The tensioning tool of  claim 14 , wherein the at least one thread engaging portion is moved into engagement with threads of the drive shaft as the carriage is rotated to the first position. 
     
     
         16 . The tensioning tool of  claim 15 , wherein the at least one thread engaging portion is moved out of engagement with threads of the drive shaft as the carriage is rotated to the second position. 
     
     
         17 . The tensioning tool of  claim 10 , wherein the drive shaft extends through at least a portion of the elongate tool body. 
     
     
         18 . The tensioning tool of  claim 17 , wherein the elongate tool body includes an elongate slot along which the carriage travels. 
     
     
         19 . The tensioning tool of  claim 18 , wherein the elongate tool body extends through the carriage with a portion of the carriage including the drive shaft passage extending into the slot for receiving the drive shaft therethrough.