Devices and methods for hip replacement

Abstract

Devices and methods for use in hip replacement surgery can incorporate computer models of a patient's acetabulum and surrounding bone structure, a first patient-specific jig designed from the computer model and configured to correspond to a final installation position and orientation of a prosthetic him implant, a second patient-specific jig, also designed from the computer model, configured to refine the procedure, if necessary, following use of the first patient-specific jig, and/or a third patient specific jig, designed from the computer model, configured to refine the procedure, if necessary, following use of the first and second patient-specific jigs, allowing the surgeon to properly position and orient the hip prosthesis. Also shown and described are novel devices for implanting an acetabular cup.

1 - 22 . (canceled) 
     
     
         23 . A method, comprising:
 using at least one bone surface image to generate three dimensional data corresponding to a bone structure of a patient;   generating a prosthesis implant image superimposed over an image of an acetabulum and positioned according to a final installation position based on the three dimensional data;   generating a patient specific jig image superimposed over the image of the acetabulum according to the installation position, the patient specific jig image having a body with at least three alignment members at positions corresponding to the installation position of the prosthesis implant image; and   generating control data from the patient specific jig image, the control data configured to control operation of a machine for making a patient-specific jig.   
     
     
         24 . The method of  claim 23  wherein generating a prosthesis implant image includes generating a guide post image at least partially positioned through the image of the acetabulum, the guide post image oriented corresponding to the installation position of the prosthesis implant image. 
     
     
         25 . The method of  claim 24  wherein generating the patient-specific jig image includes generating an aperture image through the body image of the patient-specific jig image, said aperture image in a position corresponding to the guide post image. 
     
     
         26 . The method of  claim 24 , further comprising generating a second patient-specific jig image superimposed proximate the image of the acetabulum, the second-patient specific jig image having a body image with at least three alignment member images corresponding to the installation position of the prosthesis implant image. 
     
     
         27 . The method of  claim 26  wherein generating the second patient-specific jig image includes generating an aperture image through the body image of the second patient-specific jig image, said aperture image in a position corresponding to the guide post image. 
     
     
         28 . The method of  claim 26 , further comprising generating a third patient-specific jig image superimposed proximate the image of the acetabulum, the third patient-specific jig image having a body image with at least three alignment member images corresponding to the installation position of the prosthesis implant image. 
     
     
         29 . The method of  claim 28  wherein generating the third patient-specific jig image includes generating an aperture image through the body image of the second patient-specific jig image, said aperture image in a position corresponding to the guide post image. 
     
     
         30 . The method of  claim 29 , wherein the body images of the patient specific jig, the second patient specific jig, and the third patient specific jig have different distances between respective proximal and distal ends thereof. 
     
     
         31 . A method, comprising:
 positioning a first patient-specific jig in an acetabulum of a patient, the first patient-specific jig formed according to a predetermined installation position of a prosthesis implant to be secured to the patient, the first patient-specific jig having an aperture and three alignment members attached at respective positions to the first patient-specific jig corresponding to the installation position of the prosthesis implant;   engaging each of said three alignment members to a predefined selected area of a coxal bone adjacent the acetabulum of the patient;   positioning a guide post through the aperture of the first patient-specific jig and securing the guide post to the patient, the guide post positioned corresponding to the installation position of the prosthesis implant;   removing the first patient-specific jig from the guide post; and   reaming the acetabulum with a reaming machine, the guide post configured to guide the reaming machine in a desired position during reaming, with or without the guide post in place.   
     
     
         32 . The method of  claim 31 , further comprising:
 determining whether the reaming machine reached a reference point of the installation position;   if the reaming machine reached the reference point, removing the guide post and installing the prosthesis implant in the patient using a second patient specific jig and over a guide post;   if the reaming machine has not reached the reference point, removing the guide post and positioning a second patient-specific jig in the reamed acetabulum of the patient, the second patient-specific jig formed according to the predetermined installation position, the second patient-specific jig having an aperture and three alignment members disposed at respective positions on the second patient-specific jig corresponding to the installation position;   engaging each of said three alignment members to a predefined selected area of the coxal bone proximate the acetabulum of the patient;   positioning a supplemental guide post through the aperture of the second patient-specific jig and securing the supplemental guide post to the patient, the supplemental guide post positioned corresponding to the installation position of the prosthesis implant;   removing the second patient-specific jig from the supplemental guide post and the acetabulum; and   reaming the acetabulum with a reaming machine, one of the supplemental guide post and the pilot hold sinus tract being used to guide the reaming machine in a desired position during reaming.   
     
     
         33 . The method of  claim 32 , further comprising:
 positioning a third patient-specific jig in the reamed acetabulum of the patient, the third patient-specific jig formed according to the predetermined installation position, the third patient-specific jig having an aperture to receive the supplemental guide post, the third patient-specific jig having three alignment members disposed at respective positions on the third patient-specific jig corresponding to the installation position of the prosthesis implant;   determining whether each of said three alignment members of the third patient-specific jig are engaged to said selected area proximate the acetabulum of the patient;   if each of said three alignment members of the third patient-specific jig are not engaged to said selected area, repeating said reaming operation of the previous claim and the positioning operation of the present claim until all of said three alignment members of the third patient-specific jig are engaged to said selected areas, respectively; and   if each of said three alignment members of the third patient-specific jig are engaged to said selected area, thereby indicating information that the installation reference point has been reached, securing the prosthesis implant to the reamed acetabulum over the guide post, with or without the guide post in place.   
     
     
         34 . The method of  claim 32  wherein securing the prosthesis implant includes impacting the prosthesis implant with an impactor tool, the impactor tool having a guide aperture with a central axis and configured to slidably receive a guide post secured to the patient. 
     
     
         35 . The method of  claim 34  wherein impacting the prosthesis implant with the impactor tool comprises repetitively impacting the prosthesis implant such that the guide aperture repetitively guides the impactor tool along the central axis, whereby each impact occurs approximately at the same impact point relative to the prosthesis implant. 
     
     
         36 . The method of  claim 35  comprising engaging a cannulated acetabular impactor device with the prosthesis implant, the cannulated acetabular impactor device having an aperture that receives the guide post, the cannulated acetabular impactor device having a first end biased to the prosthesis implant and a second end for impacting with the impactor tool. 
     
     
         37 . A tool used for a joint replacement prosthesis comprising a body usable to cause impact to a prosthesis implant positioned in an acetabulum of a patient, the body having an aperture with a central axis, the aperture configured to slidably receive a guide post secured to a bone of the patient and configured to guide the body along the guide post. 
     
     
         38 . The tool of  claim 37  wherein the central axis of the guide aperture is coextensive with a central axis of the guide post. 
     
     
         39 . The tool of  claim 37  wherein the aperture is configured to repetitively guide the body along the guide post such that impact caused against the prosthesis implant occurs substantially at the same impact point relative to the installation position. 
     
     
         40 . The tool of  claim 37  wherein the body is configured to impact the prosthesis implant via an elongated member positionable between the prosthesis implant and the tool. 
     
     
         41 . A device for use in implanting an acetabular cup having an exterior surface for being positioned against a patient and an opposing interior surface, the device comprising:
 an elongated shaft having an opening extending the length thereof;   an enlarged impacting end having an exterior surface shaped to complement the interior surface of the acetabular cup, the impacting end having an opening extending therethrough, the opening being aligned with the opening in the elongated shaft; and   a striking end, opposite the enlarged impacting end, the striking end having an opening therethrough, the opening being aligned with the opening in the elongated shaft.   
     
     
         42 . The device of  claim 41 , further comprising:
 a rod sized to be received by the openings in the elongated shaft and impacting and striking ends of the device, the shaft being sufficiently long to project beyond both terminal ends of the device, a first end of the elongated shaft being adapted for engagement with the patient; and   a weighted mass having an opening therethrough adapted to closely receive the rod such that the mass can slide along the rod and collide with the striking end of the device at one terminal end of its stroke, the rod maintaining the mass and the device in a desired alignment for seating the acetabular cup.   
     
     
         43 . The method of  claim 31  wherein the patient is a human.