Bone fixated, articulated joint load control device

Abstract

A load control device can be attached to bones on either side of an articulated joint in order to control the forces and loads experienced by the joint. The device comprises an apparatus for controlling the load on articular cartilage of a human or animal joint and includes: a first fixation assembly for attachment to a first bone; a second fixation assembly for attachment to a second bone; a link assembly coupled to the first fixation assembly by a first pivot and coupled to the second fixation assembly by a second pivot, the first and second fixation assembly thereby each being angularly displaceable relative to the link assembly. The apparatus enables a clinician to effectively control the environment of cartilage in a joint during a treatment episode.

1 . A device for controlling load on a knee joint, the device comprising:
 first and second fixation assemblies configured for attachment to a side of a knee joint;   a link assembly connectable to the first and second fixation assemblies at first and second pivots respectively, wherein the link assembly is configured to provide a variable distance of separation of the first and second pivots;   wherein the link assembly comprises a spring; and   wherein the spring is arranged in the link assembly to bias the first and second pivots away from one another.   
     
     
         2 . The device of  claim 1 , wherein the first and second pivots comprise articulating surfaces. 
     
     
         3 . The device of  claim 1 , wherein the link assembly is configured to be positioned entirely outside of the articular surfaces of the knee joint. 
     
     
         4 . The device of  claim 1 , further comprising a first fastener configured to extend through the first fixation assembly and into the femur; and
 a second fastener configured to extend through the second fixation assembly and into the tibia.   
     
     
         5 . The device of  claim 1 , wherein the spring comprises a coil spring. 
     
     
         6 . The device of  claim 1 , wherein the link assembly is configured to act in compression to counteract the natural compressive forces experienced by the knee joint. 
     
     
         7 . The device of  claim 1 , wherein the link assembly comprises means to apply a force in a direction of distraction of the knee joint. 
     
     
         8 . The device of  claim 1 , wherein the link assembly comprises a central shaft. 
     
     
         9 . The device of  claim 8 , wherein the link assembly comprises a hub mounted to the central shaft and configured to contact an end of the spring. 
     
     
         10 . The device of  claim 8 , wherein the central shaft extends through the spring. 
     
     
         11 . A device for controlling load on a joint, the device comprising:
 first and second fixation assemblies configured for attachment to a side of a joint;   a link assembly connectable to the first and second fixation assemblies at first and second pivots respectively, wherein the link assembly is configured to provide a variable distance of separation of the first and second pivots;   wherein the link assembly comprises a spring; and   wherein the spring is arranged in the link assembly to bias the first and second pivots away from one another.   
     
     
         12 . The device of  claim 11 , wherein the first and second pivots comprise articulating surfaces. 
     
     
         13 . The device of  claim 11 , wherein the link assembly is configured to be positioned entirely outside of the articular surfaces of the joint. 
     
     
         14 . The device of  claim 11 , further comprising a first fastener configured to extend through the first fixation assembly and into a first bone of the joint; and
 a second fastener configured to extend through the second fixation assembly and into a second bone of the joint.   
     
     
         15 . The device of  claim 11 , wherein the spring comprises a coil spring. 
     
     
         16 . The device of  claim 11 , wherein the link assembly is configured to act in compression to counteract the natural compressive forces normally experienced by the joint. 
     
     
         17 . The device of  claim 11 , wherein the link assembly comprises means to apply a force in a direction of distraction of the joint. 
     
     
         18 . The device of  claim 11 , wherein the link assembly comprises a central shaft. 
     
     
         19 . The device of  claim 18 , wherein the link assembly comprises a hub mounted to the central shaft and configured to contact an end of the spring. 
     
     
         20 . The device of  claim 18 , wherein the central shaft extends through the spring. 
     
     
         21 . A device for controlling load on a joint, the device comprising:
 first and second fixation assemblies configured for attachment to a side of a joint;   a link assembly connectable to the first and second fixation assemblies at first and second pivot means respectively, wherein the link assembly is configured to provide a variable distance of separation of the first and second pivot means;   wherein the link assembly comprises a means for biasing; and   wherein the means for biasing is arranged in the link assembly to bias the first and second pivot means away from one another.   
     
     
         22 . The device of  claim 21 , wherein the first and second pivot means comprise articulating surfaces. 
     
     
         23 . The device of  claim 21 , wherein the link assembly is configured to be positioned entirely outside of the articular surfaces of the joint. 
     
     
         24 . The device of  claim 21 , further comprising a first fastener means configured to extend through the first fixation assembly and into the femur; and
 a second fastener means configured to extend through the second fixation assembly and into the tibia.   
     
     
         25 . The device of  claim 21 , wherein the means for biasing comprises a coil spring. 
     
     
         26 . The device of  claim 21 , wherein the link assembly is configured to act in compression to counteract the natural compressive forces experienced by the joint. 
     
     
         27 . The device of  claim 21 , wherein the link assembly comprises means to apply a force in a direction of distraction of the joint. 
     
     
         28 . The device of  claim 21 , wherein the link assembly comprises a central shaft. 
     
     
         29 . The device of  claim 28 , wherein the link assembly comprises a hub mounted to the central shaft and configured to contact an end of the means for biasing. 
     
     
         30 . The device of  claim 28 , wherein the central shaft extends through the means for biasing.