Precise femoral component positioning for hip replacement surgery

Abstract

A method for accurately positioning the acetabular cup in a minimally invasive total hip arthroplasty (THA), comprising the steps of (a) placing the cup in roughly the correct position in the acetabulum using a acetabular component placement tool, (b) taking a first abduction reading and a first anteversion reading using a gyroscopic positioning unit aligned with the acetabular component placement tool, (c) taking an image of at least a portion of the cup using a radiography unit, (d) using the image to determine the actual orientation of the cup and required position of the cup to properly orient the acetabular component, (e) incrementally altering the position of the cup by using a striking tool, (f) taking new abduction and anteversion readings using the gyroscopic unit to determine the relative movement of the cup caused by the tapping, and (g) repeating any of the steps as necessary.

1 . A femoral broach tool, comprising:
 a. a connecting member configured to receive a femoral broach, the connecting member defining a central axis;   b. a striking post connected to the connecting member, the striking post defining a surface generally perpendicular to the central axis; and   c. a directional mount attached to the connecting member to receive a directional device, wherein the directional mount is configured to cause the directional device to emit a visual guide parallel to the central axis.   
     
     
         2 . The femoral broach tool of  claim 1  wherein the visual guide is offset from the central axis and which offset can be adjusted depending on the size of a patient and a thickness of soft tissues adjacent to a wound. 
     
     
         3 . The femoral broach tool of  claim 1  wherein the directional mount is angularly adjustable about the central axis. 
     
     
         4 . The femoral broach tool of  claim 1  wherein the directional device is a laser pointer and the visual guide is a laser light. 
     
     
         5 . The femoral broach tool of  claim 1  further comprising a gyroscopic unit mountable to the connecting member. 
     
     
         6 . The femoral broach tool of  claim 1  wherein the femoral broach tool is configured to receive a gyroscopic unit. 
     
     
         7 . The femoral broach tool of  claim 6  further comprising a gyroscope mount attached to the connecting member, wherein the gyroscope mount is angularly adjustable about the central axis. 
     
     
         8 . A femoral broach tool, comprising:
 a. a connecting member configured to receive a femoral broach, the connecting member defining a central axis; and   b. a directional mount attached to the connecting member to receive a directional device, wherein the directional mount is configured to cause the directional device to emit a visual guide parallel to the central axis.   
     
     
         9 . The femoral broach tool of  claim 8  wherein the visual guide is offset from the central axis and which offset can be adjusted depending on the size of a patient and a thickness of soft tissues adjacent to a wound. 
     
     
         10 . The femoral broach tool of  claim 8  wherein the directional mount is angularly adjustable about the central axis. 
     
     
         11 . The femoral broach tool of  claim 8  wherein the directional device is a laser point and the visual guide is a laser light. 
     
     
         12 . The femoral broach tool of  claim 8  further comprising a gyroscopic unit mountable to the connecting member. 
     
     
         13 . The femoral broach tool of  claim 8  wherein the femoral broach tool is configured to receive a gyroscopic unit. 
     
     
         14 . The femoral broach tool of  claim 8  further comprising a gyroscope mount attached to the connecting member, wherein the gyroscope mount is angularly adjustable about the central axis. 
     
     
         15 . A method for preparing a femur for a total hip arthroplasty, comprising:
 a. aligning a femoral broach tool along the femur with a directional device emitting a guide to identify a line of attack directed towards a chosen target; and   b. displacing bone material from the femur with the femoral broach tool by tapping the femoral broach tool into the femur while maintaining the line of attack according to the guide.   
     
     
         16 . The method of  claim 15  wherein the femoral broach tool comprises:
 a. a femoral broach mounted to a broach handle, the broach handle connected to a strike plate, and 
 b. a mount connected to the broach handle to support the directional device, wherein the femoral broach tool defines a central axis and the line of attack is parallel to the central axis. 
 
     
     
         17 . The method of  claim 15  wherein the mount is adjustably connected to the broach handle in such a way as to allow the mount to rotate about the broach handle as well as slide along the broach handle. 
     
     
         18 . The method of  claim 15  wherein the mount comprises a lock to fix the directional device in place. 
     
     
         19 . The method of  claim 15  further comprising adjusting the femoral broach tool based on a reading from a gyroscopic unit. 
     
     
         20 . The method of  claim 15  wherein the femoral broach tool further comprises a second mount to receive a gyroscopic unit.