Fixation device and multiple-axis joint for a fixation device

Abstract

A fixator system includes an active strut that that can be gradually or acutely adjusted. Adjustments can be made in six degrees of freedom. Embodiments of the active strut can provide for two of the six degrees of freedom being about a first common point of rotation, and another two of the six degrees of freedom being about a second common point of rotation. Embodiments of the fixator can include one or more active struts in combination with one or more passive struts. The passive struts can be rigidly locked or can be unlocked so as to be freely and acutely adjustable while gradual or acute adjustments are made using the one or more active struts.

What is claimed is: 
     
         1 . A fixator system, comprising:
 a first fixator base element;   a second fixator base element;   a first active strut connected between the first fixator base element and the second fixator base element; and   a first passive strut connected between the first fixator base element and the second fixator base element;   wherein the first passive strut is configured to be placed into a passive locked state such that the first passive strut is non-adjustable and resists relative positional changes between the first and second fixator base elements, and placed into an unlocked state such that the first passive strut freely allows relative positional changes between the first and second fixator base elements;   wherein the first active strut is configured to be placed into an active locked state such that the first active strut resists relative positional changes between the first and second fixator base elements, and placed into an unlocked state such that the first active strut freely allows relative positional changes between the first and second fixator base elements;   wherein the first active strut is configured to allow relative positional changes between the first and second fixator base elements while maintaining rigidity while the first active strut is in the active locked state; and   wherein the first active strut is configured to allow adjustment of an overall length of the first active strut when the first active strut is in the active locked state.   
     
     
         2 . The fixator system of  claim 1 , further comprising a second active strut connected between the first fixator base element and the second fixator base element;
 wherein the second active strut is configured to be placed into an active locked state such that the second active strut resists relative positional changes between the first and second fixator base elements, and placed into an unlocked state such that the second active strut freely allows relative positional changes between the first and second fixator base elements;   wherein the second active strut is configured to allow relative positional changes between the first and second fixator base elements while maintaining rigidity while the second active strut is in the active locked state; and   wherein the second active strut is configured to allow adjustment of an overall length of the second active strut when the second active strut is in the active locked state.   
     
     
         3 . The fixator system of  claim 1 , further comprising a second passive strut connected between the first fixator base element and the second fixator base element;
 wherein the second passive strut is configured to be placed into a passive locked state such that the second passive strut is non-adjustable and resists relative positional changes between the first and second fixator base elements, and placed into an unlocked state such that the second passive strut freely allows relative positional changes between the first and second fixator base elements.   
     
     
         4 . The fixator system of  claim 1 , wherein the first active strut includes a joint comprising a driven element attached to the first fixator base element, a first drive system that rotates the driven element about a first axis of rotation, and a second drive system that rotates the driven element about a second axis of rotation, wherein the first and second axes intersect at a common point of rotation of the driven element. 
     
     
         5 . The fixator system of  claim 1 , wherein the first active strut is configured to be placed into a passive locked state such that the first active strut is non-adjustable and resists relative positional changes between the first and second fixator base elements. 
     
     
         6 . A strut for a fixator system, the strut comprising:
 a first joint;   a second joint; and   a central portion connected between the first and second joints, the central portion being adjustable in at least two degrees of freedom;   wherein the strut is configured to be placed into an active locked state such that the strut resists relative positional changes between the first and second joints, and placed into an unlocked state such that the strut freely allows relative positional changes between the first and second joints;   wherein the strut is configured to allow for relative positional changes between the first joint and the second joint while maintaining rigidity while the strut is in the active locked state; and   wherein the strut is configured to allow for adjustment of an overall length of the strut when the strut is in the active locked state.   
     
     
         7 . The strut of  claim 6 , wherein the first joint further comprises:
 a first drive system that rotates a first driven element of the first joint about a first axis of the first joint; and   a second drive system that rotates the first driven element about a second axis of the first joint;   wherein the first and second axes intersect about a first common point of rotation of the first driven element.   
     
     
         8 . The strut of  claim 6 , wherein the central portion is lengthwise adjustable. 
     
     
         9 . The strut of  claim 6 , wherein the strut is configured to be placed into a passive locked state such that the strut is non-adjustable and resists relative positional changes between the first and second joints. 
     
     
         10 . A fixator system, comprising:
 a first fixator base element;   a second fixator base element;   a first active strut connected between the first fixator base element and the second fixator base element; and   a first passive strut connected between the first fixator base element and the second fixator base element;   wherein the first passive strut is configured to be placed into a passive locked state such that the first passive strut is non-adjustable and resists relative positional changes between the first and second fixator base elements, and placed into an unlocked state such that the first passive strut freely allows relative positional changes between the first and second fixator base elements;   wherein the first active strut is configured to be
 placed into an active locked state such that the first active strut resists relative positional changes between the first and second fixator base elements, 
 placed into a passive locked state such that the first active strut is non-adjustable and resists relative positional changes between the first and second fixator base elements, and 
 placed into an unlocked state such that the first active strut freely allows relative positional changes between the first and second fixator base elements; and 
   wherein the first active strut is configured to allow relative positional changes between the first and second fixator base elements while maintaining rigidity while the first active strut is in the active locked state.   
     
     
         11 . The fixator system of  claim 10 , further comprising a second active strut connected between the first fixator base element and the second fixator base element;
 wherein the second active strut is configured to be
 placed into an active locked state such that the second active strut resists relative positional changes between the first and second fixator base elements, 
 placed into a passive locked state such that the second active strut is non-adjustable and resists relative positional changes between the first and second fixator base elements, and 
 placed into an unlocked state such that the second active strut freely allows relative positional changes between the first and second fixator base elements; and 
   wherein the second active strut is configured to allow relative positional changes between the first and second fixator base elements while maintaining rigidity while the second active strut is in the active locked state.   
     
     
         12 . The fixator system of  claim 10 , further comprising a second passive strut connected between the first fixator base element and the second fixator base element;
 wherein the second passive strut is configured to be placed into a passive locked state such that the second passive strut is non-adjustable and resists relative positional changes between the first and second fixator base elements, and placed into an unlocked state such that the second passive strut freely allows relative positional changes between the first and second fixator base elements.   
     
     
         13 . The fixator system of  claim 10 , wherein the first active strut includes a joint comprising a driven element attached to the first fixator base element, a first drive system that rotates the driven element about a first axis of rotation, and a second drive system that rotates the driven element about a second axis of rotation, wherein the first and second axes intersect at a common point of rotation of the driven element. 
     
     
         14 . The fixator system of  claim 10 , wherein the first active strut is configured to allow adjustment of an overall length of the first active strut when the first active strut is in the active locked state. 
     
     
         15 . A strut for a fixator system, the strut comprising:
 a first joint;   a second joint; and   a central portion connected between the first and second joints, the central portion being adjustable in at least two degrees of freedom;   wherein the strut is configured to be
 placed into an active locked state such that the strut resists relative positional changes between the first and second joints, 
 placed into a passive locked state such that the strut is non-adjustable and resists relative positional changes between the first and second joints, and 
 placed into an unlocked state such that the strut freely allows relative positional changes between the first and second joints; and 
   wherein the strut is configured to allow for relative positional changes between the first joint and the second joint while maintaining rigidity while the strut is in the active locked state.   
     
     
         16 . The strut of  claim 15 , wherein the first joint further comprises:
 a first drive system that rotates a first driven element of the first joint about a first axis of the first joint; and   a second drive system that rotates the first driven element about a second axis of the first joint;   wherein the first and second axes intersect about a first common point of rotation of the first driven element.   
     
     
         17 . The strut of  claim 15 , wherein the central portion is lengthwise adjustable. 
     
     
         18 . The strut of  claim 15 , wherein the strut is configured to allow for adjustment of an overall length of the strut when the strut is in the active locked state.