Telescopic strut for an external fixator

Abstract

A telescopic strut for use with an external fixator comprising an axially extending rod; an axially extending tube moveably recurring the rod for varying the length of the rod and tube combination along a longitudinal axis; the tube having first and second ends, the second end having a pin extending therethrough; a locking system mounted on the tube first end for adjusting the position of the rod in the tube and fixing the length of the rod and tube combination; a coupling element having a tubular sleeve with a threaded outer surface mounted on an outer surface of the second end of the tube, the sleeve having two diametrically opposed slots receiving the pin and an adjustment element threadably mounted on the sleeve outer surface for axial movement along the axis, the adjustment element having a surface contacting the pin to limit the movement of the pin in the slots.

1 . (canceled) 
     
     
         2 . A system for adjusting a relative orientation of a pair of spaced rings of an external fixator, comprising;
 a rod extending between a first end and a second end along a first axis;   a tubular element extending between a first end and a second end along the first axis, the first end of the tubular element for receiving the first end of the rod;   a first coupling element attached to the second end of the rod for coupling the rod to one of the pair of spaced rings, the first coupling element comprising:
 a tube having a first end and a second end opposite the first end, the first end of the tube being fixed to the second end of the rod, the second end of the tube having an outer part-spherical surface and an inner part-spherical recess; 
 a shaft extending from a first end to a second end, the second end of the shaft having a part-spherical recess that at least partially overlies and is in contact with the outer part-spherical surface of the tube; and 
 a nut extending from a first end to a second end, the first end of the nut being positioned within the second end of the tube and having an outer part-spherical surface in contact with the part-spherical recess of the tube, the second end of the nut being positioned within the second end of the shaft, 
   the shaft and the nut each being articulable with respect to the tube; and   a second coupling element attached to the second end of the tubular element for coupling the tubular element to the other of the pair of spaced rings.   
     
     
         3 . The system of  claim 2 , wherein the outer part-spherical surface of the tube includes a roughened area. 
     
     
         4 . The system of  claim 3 , wherein the roughened area includes ridges. 
     
     
         5 . The system of  claim 2 , wherein the first coupling further includes a tightening element extending at least partially through a bore in the shaft and a bore in the nut. 
     
     
         6 . The system of  claim 5 , wherein the first coupling element has a loosened condition in which the shaft and the nut are each articulable with respect to the tube, and a tightened condition in which the shaft and the nut are locked from articulating with respect to the tube. 
     
     
         7 . The system of  claim 6 , wherein in the loosened condition of the first coupling element, the nut has a first position relative to the tightening element, and in the tightened condition of the first coupling element, the nut has a second position relative to the tightening element, actuation of the tightening element sliding the nut from the first position to the second position. 
     
     
         8 . The system of  claim 7 , wherein the tightening element is a screw having outer threads coupled to inner threads of the nut. 
     
     
         9 . The system of  claim 7 , wherein the second end of the tube includes at least two longitudinal slits therein. 
     
     
         10 . The system of  claim 9 , wherein the second end of the tube is in a flexed condition when the first coupling element is in the tightened condition, and in an unflexed condition when the first coupling element is in the loosened condition. 
     
     
         11 . The system of  claim 6 , wherein the bore of the shaft includes a first bore portion in the first end of the shaft having a first diameter and a second bore portion in the second end of the shaft having a second diameter larger than the first diameter, the first bore portion being continuous with the second bore portion. 
     
     
         12 . The system of  claim 11 , wherein the tightening element extends through the first and second bore portions of the shaft. 
     
     
         13 . The system of  claim 12 , wherein the second end of the nut has an outer diameter that is smaller than the second diameter of the second bore portion and larger than the first diameter of the first bore portion. 
     
     
         14 . The system of  claim 11 , wherein the first bore portion, the second bore portion, and the shaft each extend along a second axis. 
     
     
         15 . The system of  claim 14 , wherein in the loosened condition of the first coupling element, the first axis is moveable with respect to the second axis, and in the tightened condition of the first coupling element, the first axis is fixed with respect to the second axis. 
     
     
         16 . The system of  claim 2 , wherein the second coupling element comprises:
 a second tube having a first end and a second end opposite the first end, the first end of the second tube being fixed to the second end of the tubular element, the second end of the second tube having an outer part-spherical surface and an inner part-spherical recess;   a second shaft extending from a first end to a second end, the second end of the second shaft having a part-spherical recess that at least partially overlies and is in contact with the outer part-spherical surface of the second tube; and   a second nut extending from a first end to a second end, the first end of the second nut being positioned within the second end of the second tube and having an outer part-spherical surface in contact with the part-spherical recess of the second tube, the second end of the second nut being positioned within the second end of the second shaft,   the second shaft and the second nut each being articulable with respect to the second tube.