System and Method for Surgical Planning

Abstract

A system and method for determining inclination and version of a prosthetic acetabular cup relative to a coronal radiographic plane is provided. The system and method include the identification of a coronal radiographic plane in a three dimensional medical image. The system and method further include the identification of two symmetric landmarks on the pelvis to determine a mediolateral axis. The version and inclination can then be calculated based on the relationship between the axis of the acetabular cup, the coronal radiographic plan, and the mediolateral axis.

1 . A method of planning and performing a surgical procedure, comprising the steps of:
 determining a coronal radiographic plane of a patient based on a medical image of the patient's pelvis;   identifying two landmarks within the medical image; and   determining a version and inclination of a virtual model of an acetabular cup based on a relationship between the virtual model of the acetabular cup, the coronal radiographic plane, and the two landmarks.   
     
     
         2 . The method of  claim 1 , wherein the two landmarks are substantially symmetrical with each other about a median plane of the patient. 
     
     
         3 . The method of  claim 2 , wherein the two landmarks are located on the pelvis. 
     
     
         4 . The method of  claim 1 , further comprising the step of determining a mediolateral axis based on the positions of the two landmarks. 
     
     
         5 . The method of  claim 4 , further comprising the step of determining a longitudinal axis based on the mediolateral axis and the coronal radiographic plane. 
     
     
         6 . The method of  claim 1 , wherein the version is calculated as the angle between an axis of the virtual model of the acetabular cup and the coronal radiographic plane. 
     
     
         7 . The method of  claim 5 , wherein the inclination is calculated as the angle between a projection of an axis of the virtual model of the acetabular cup onto the coronal radiographic plane and the longitudinal axis. 
     
     
         8 . The method of  claim 1 , further comprising the step of guiding a reamer to prepare an acetabulum of the pelvis to receive the acetabular cup at a predetermined version and inclination. 
     
     
         9 . The method of  claim 1 , further comprising the step of determining a preoperative version and inclination of an acetabulum of the pelvis based on a relationship between the acetabulum, the coronal radiographic plane, and the two landmarks. 
     
     
         10 . The method of  claim 1 , further comprising the step of guiding a user during impaction of the acetabular cup. 
     
     
         11 . The method of  claim 1 , further comprising the step of determining a post-impaction version and inclination of the acetabular cup based on a relationship between the post-impaction orientation of the acetabular cup, the coronal radiographic plane, and the two landmarks. 
     
     
         12 . The method of  claim 1 , further comprising the step of adjusting the orientation of the coronal radiographic plane based on the position of the two landmarks. 
     
     
         13 . A method of planning and performing a surgical procedure, comprising the steps of:
 receiving a medical image of a patient's pelvis;   determining a coronal radiographic plane of the patient based on the medical image;   identifying two landmarks within the medical image;   determining a longitudinal axis based on the two landmarks and the coronal radiographic plane; and   determining a version and an inclination of a virtual model of an acetabular cup based on a relationship between the virtual model of the acetabular cup, the coronal radiographic plane, and the longitudinal axis.   
     
     
         14 . The method of  claim 13 , further comprising the steps of determining a mediolateral axis based on the positions of the two landmarks, and determining the longitudinal axis based on the mediolateral axis and the coronal radiographic plane. 
     
     
         15 . The method of  claim 13 , wherein the version is calculated as the angle between an axis of the virtual model of the acetabular cup and the coronal radiographic plane, and the inclination is calculated as the angle between a projection of an axis of the virtual model of the acetabular cup onto the coronal radiographic plane and the longitudinal axis. 
     
     
         16 . The method of  claim 13 , further comprising the step of adjusting the orientation of the coronal radiographic plane based on the positions of the two landmarks. 
     
     
         17 . A system for planning and performing a surgical procedure, comprising:
 an input device;   an output device; and   a controller in communication with each of the input device and output device, the controller being configured to access a medical image of a patient's pelvis, determine a coronal radiographic plane of the patient based on the medical image, identify two landmarks within the medical image, and determine a version and inclination of a virtual model of an acetabular cup based on a relationship between the virtual model of the acetabular cup, the coronal radiographic plane, and the two landmarks.   
     
     
         18 . The system of  claim 17 , wherein the controller is configured to guide a reamer to prepare an acetabulum of the pelvis to receive the acetabular cup at a predetermined version and inclination. 
     
     
         19 . The system of  claim 17 , wherein the controller is configured to determine a preoperative version and inclination of an acetabulum of the pelvis based on a relationship between the acetabulum, the coronal radiographic plane, and the two landmarks. 
     
     
         20 . The system of  claim 17 , wherein the controller is configured to guide a user during impaction of the acetabular cup, and determine a post-impaction version and inclination of the acetabular cup based on a relationship between the post-impaction orientation of the acetabular cup, the coronal radiographic plane, and the two landmarks.