Alignment apparatus for use in hip arthroplasty

Abstract

Hip arthroplasty apparatus and methods are described to determine an orientation of an acetabular cup impactor, the acetabular cup impactor being moveable to a desired orientation relative to a patient's pelvic region for implantation of an acetabular cup. In one embodiment an electronic orientation sensor is transitionable between a first location on the patient's pelvic region and a second location on the acetabular cup impactor. At the first location, the orientation sensor is adapted to record a reference orientation of the patient's pelvic region. At the second location the orientation sensor is adapted to determine an orientation of the acetabular cup impactor relative to the reference orientation.

1 . Hip arthroplasty apparatus comprising:
 an acetabular cup impactor moveable to a desired orientation relative to a patient's pelvic region for implantation of an acetabular cup; and   an electronic orientation sensor transitionable between a first location on the patient's pelvic region and a second location on the acetabular cup impactor;   wherein, at the first location, the orientation sensor is adapted to record a reference orientation of the patient's pelvic region, and, at the second location, the orientation sensor is adapted to determine an orientation of the acetabular cup impactor relative to the reference orientation.   
     
     
         2 . The apparatus of  claim 1 , wherein the apparatus comprises a first mount that is configured to engage both the orientation sensor and the pelvic region and releasably fix the positions of the orientation sensor and the pelvic region relative to each other when the orientation sensor is located at the first location. 
     
     
         3 . The apparatus of  claim 1 , wherein the apparatus comprises a second mount that is configured to engage both the orientation sensor and the impactor and releasably fix the positions of the orientation sensor and the impactor relative to each other when the orientation sensor is located at the second location. 
     
     
         4 . The apparatus of  claim 1 , wherein the orientation sensor is adapted to determine the orientation of the acetabular cup impactor relative to the reference orientation in three-dimensional space. 
     
     
         5 . The apparatus of  claim 1 , wherein the orientation sensor comprises one or more gravitational field sensors. 
     
     
         6 . The apparatus of  claim 1 , wherein the orientation sensor comprises one or more accelerometers. 
     
     
         7 . The apparatus of  claim 1 , wherein the orientation sensor comprises one or more magnetic field sensors. 
     
     
         8 . The apparatus of  claim 1 , wherein the orientation sensor comprises one or more gyroscopes. 
     
     
         9 . The apparatus of  claim 1 , comprising an output device adapted to provide information about the determined relative orientation of the impactor and/or the recorded reference orientation to a clinician or other user. 
     
     
         10 . The apparatus of  claim 1 , wherein the orientation sensor is comprised in a smartphone or a tablet computer. 
     
     
         11 . (canceled) 
     
     
         12 . (canceled) 
     
     
         13 . (canceled) 
     
     
         14 . Hip arthroplasty apparatus comprising:
 an image capture device adapted to mount on one of an acetabular cup impactor and a patient's pelvic region, the acetabular cup impactor being moveable to a desired orientation relative to the patient's pelvic region for implantation of an acetabular cup, wherein the image capture device is adapted to capture images of the other of the acetabular cup impactor and the patient's pelvic region, including one or more first markers positioned on that other of the acetabular cup impactor and the pelvic region;   a display device connected to the image capture device and adapted to display images captured from the image capture device; and   a processor adapted to cause overlay of one or more second markers in the images displayed by the display device such that, when one or more of the first markers shown in the displayed images are substantially aligned with one or more of the second markers overlaid in the displayed images, the acetabular cup impactor is oriented in the desired orientation.   
     
     
         15 . The apparatus of  claim 14 , wherein the image capture device is adapted to be mounted on the impactor, and the image capture device is adapted to capture images of the patient's pelvic region, including one or more first markers positioned at the patient's pelvic region. 
     
     
         16 . The apparatus of  claim 15 , wherein the one or more first markers comprise one or more anatomical landmarks. 
     
     
         17 . The apparatus of  claim 15 , wherein the one or more first markers comprise a real or imaginary line drawn between the anterior superior iliac spines. 
     
     
         18 . The apparatus of  claim 15 , wherein the processor is adapted to determine a position and/or orientation for the one or more second markers to be overlaid in the images based on received orientation data including a desired orientation angle of the acetabular cup impactor and a measured orientation angle of the acetabular cup impactor. 
     
     
         19 . The apparatus of  claim 18  wherein:
 the measured orientation angle is a measured angle of anteversion of the impactor and the desired orientation angle is a desired angle of inclination of the impactor; or 
 the measured orientation angle is a measured angle of inclination of the impactor and the desired orientation angle is a desired angle of anteversion of the impactor. 
 
     
     
         20 . The apparatus of  claim 15 , comprising a tilt sensor adapted to determine the tilt of the impactor. 
     
     
         21 . The apparatus of  claim 20  when dependent on  claim 18  or  19 , wherein the measured orientation angle is obtained using the tilt sensor. 
     
     
         22 . The apparatus of  claim 21 , wherein the processor is adapted to present the measured angle determined by the tilt sensor in the images displayed by the display device and wherein the second markers in the images displayed by the display device are such that, when one or more of the first markers shown in the displayed images are substantially aligned with one or more of the second markers overlaid in the displayed images, the acetabular cup impactor is substantially oriented at the desired orientation angle. 
     
     
         23 . The apparatus of  claim 20 , wherein the tilt sensor and the image capture device are integrated in a single electronic device. 
     
     
         24 - 56 . (canceled)