Systems And Methods For Determining A Joint Center Of Rotation During A Procedure

Abstract

Systems and methods are described to determine joint center of rotation during a procedure. Joint center measurements may be useful to determine other clinically relevant measurements and/or to assist with replacement surgery.

We claim: 
     
         1 . A system to determine a center of rotation of a joint during a surgical procedure, comprising:
 an electronic guidance system comprising a target to generate relative poses between a first bone and an object, wherein the first bone and the object are connected via the joint having the center of rotation; and   a computing unit comprising circuitry configured to:
 collect an articulation data set comprising poses from the electronic guidance system wherein the poses relate to a target attached to a tool, and wherein the tool is articulated about the center of rotation; and 
 calculate a joint center of rotation responsive to the articulation data set to guide the surgical procedure. 
   
     
     
         2 . The system of  claim 1 , wherein the joint is a native joint of a patient. 
     
     
         3 . The system of  claim 2 , wherein the object is a femur of the patient and the tool comprises a corkscrew tool attached to a part of the femur. 
     
     
         4 . The system of  claim 3 , wherein the part of the femur is a resected femoral head prior to dislocation. 
     
     
         5 . The system of  claim 2 , wherein the computing unit is further configured to: after a reconstruction of the native joint to define a reconstructed joint having a second center of rotation, collect a second articulation data set of the reconstructed joint; and calculate a second joint center of rotation from rotation of the target about the second center of rotation of the reconstructed joint. 
     
     
         6 . The system of  claim 5 , wherein the computing unit is further configured to calculate a spatial difference between the joint center of rotation of the native joint and the second joint center of rotation. 
     
     
         7 . The system of  claim 6 , wherein the computing unit is further configured to display the spatial difference. 
     
     
         8 . The system of  claim 1 , wherein the center of rotation is of a reconstructed joint comprising implant components. 
     
     
         9 . The system of  claim 8 , wherein the tool comprises a distal end configured to mate with a spherical implant component. 
     
     
         10 . The system of  claim 9 , wherein the implant component is a liner component, and the tool is a liner insertion tool. 
     
     
         11 . The system of  claim 1 , wherein the surgical procedure is a joint replacement, and the joint is one of: a hip joint and a shoulder joint. 
     
     
         12 . The system of  claim 1 , wherein the surgical procedure is a direct anterior hip replacement. 
     
     
         13 . The system of  claim 1 , wherein the computing unit is further configured to calculate a change in limb length based on the joint center of rotation. 
     
     
         14 . The system of  claim 1 , wherein the computing unit is further configured to guide a collection of the articulation data set, displaying information via a display device for performing the collection. 
     
     
         15 . The system of  claim 14  further configured to detect an error as a pose is collected, comparing a pose to an expected profile determine from prior poses. 
     
     
         16 . A method to determine a center of rotation of a joint during a surgical procedure, the method comprising:
 collecting an articulation data set comprising poses from an electronic guidance system comprising a target to generate relative poses between a first bone and an object, wherein:
 the first bone and the object are connected via the joint having the center of rotation; and 
 the poses of the articulation data set relate to the target attached to a tool as the tool is articulated about the center of rotation; and 
   calculating a joint center of rotation responsive to the articulation data set to guide the surgical procedure.   
     
     
         17 . The method of  claim 16  comprising:
 determining a second joint centre of rotation the joint after a reconstruction; 
 calculating a spatial difference between the joint center of rotation and the second joint center of rotation; and 
 displaying the spatial difference. 
 
     
     
         18 . The method of  claim 16  comprising guiding a collection of the articulation data set, displaying information via a display device for performing the collection. 
     
     
         19 . A method comprising:
 preparing a joint of a patient for a surgical procedure, the joint connecting a first bone to an object and the joint having a center of rotation;   coupling to the object a target of an electronic guidance system configured to generate relative poses between the first bone and the object using the target;   rotating the target about the center of rotation to provide an articulation data set comprising poses from the electronic guidance system to a computing unit configured to calculate a joint center of rotation for the joint responsive to the articulation data set.   
     
     
         20 . The method of  claim 18  further comprising:
 reconstructing the joint; 
 mating an implant interfacing tool with the joint as reconstructed, the interfacing tool coupled to the target; 
 using the electronic guidance system and the computing unit to determine a second joint center of rotation for the joint as reconstructed; and 
 receiving joint center of rotation difference information from the computing unit.