Computer assisted insertion of an artificial hip joint

Abstract

A system and a method for ensuring correct insertion of the components of a femoral prosthesis, i.e. a prosthesis stem with a ball head and a cup with recess for receipt of the ball head, is described. The system comprises a tool for controlling the mutual angle between the prosthesis stem and the cup in addition to a positioning system for definition of a reference system and for determination and adjustment of the offset and length of the leg.

1 - 18 . (canceled)  
   
   
       19 . A system of ensuring the desired mutual positioning of the main components of an artificial hip joint prosthesis, the prosthesis including a prosthesis stem with a ball head and a cap with a recess for receipt of the ball head, the system comprising: 
 a positioning tool configured to interact with a neck of the prosthesis stem and the cup, wherein an angle between the prosthesis stem and the cup can be controlled;    at least one sensor placed at the positioning tool;    a position determination instrument in operative communication with said at least one sensor, said position determination instrument configured to read a position and an orientation within a room.    
   
   
       20 . The system of claim  1  wherein said position determination instrument comprises a sensor fastened to a pelvis.  
   
   
       21 . The system of claim  1  wherein said position determination instrument comprises a conversion unit configured to convert the position of said at least one sensor to said angle between the prosthesis stem and the cup.  
   
   
       22 . The system of claim  1  wherein said position determination instrument comprises an additional sensor, said additional sensor configured to be fastened to a femur, said additional sensor configured to measure at least one of a spatial angle, an offset and a length of said femur.  
   
   
       23 . The system of claim  1  wherein said position determination instrument comprises a source for a magnetic field, at least one sensor, a calculation unit and a display unit for presentation of the position of said at least one sensor.  
   
   
       24 . The system of claim  1  wherein said position determination instrument comprises a conversion unit, configured to convert the spatial position of said at least one sensor to a predetermined angle.