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 hip 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 . A method, comprising:
 positioning a first component of a patient-specific jig in an acetabulum of a patient, the patient-specific jig formed according to a predetermined installation position of a prosthesis implant to be secured to the patient, the first component of the patient-specific jig having a first aperture, a first alignment member attached at a respective position to the first component of the patient-specific jig corresponding to the installation position of the prosthesis implant, and a first alignment structure;   engaging the first alignment member to a predefined selected area of a coxal bone adjacent the acetabulum of the patient;   positioning a second component of the patient-specific jig in the first aperture of the first component of the patient-specific jig and in an acetabulum of a patient, the second component of the patient-specific jig formed according to a predetermined installation position of a prosthesis implant to be secured to the patient, the second component of the component of the patient-specific jig having a second aperture and a second alignment structure, the second alignment structure to engage with the first alignment structure at a respective position corresponding to the installation position of the prosthesis implant;   positioning a guide post through the aperture of the second component of the 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 second component of the patient-specific jig from the acetabulum in a direction substantially parallel to a central axis of the guide post;   removing the first component of the patient-specific jig from the acetabulum.   
     
     
         2 . The method of  claim 1 , further comprising:
 determining whether the acetabulum has been reamed to receive a prosthetic acetabular cup;   if the acetabulum has not been reamed to receive a prosthetic acetabular cup, reaming the acetabulum; and   if the acetabulum has been reamed to receive a prosthetic acetabular cup, securing the prosthesis implant to the acetabulum.   
     
     
         3 . The method of  claim 2  wherein the step of determining whether the acetabulum has been reamed to receive a prosthetic acetabular cup, further comprises:
 determining whether the first alignment member of the first component of the patient-specific jig is engaged to the selected area proximate the acetabulum of the patient and determining whether the second alignment structure is engaged with the first alignment structure at a respective position corresponding to the installation position of the prosthesis implant; 
 if the first alignment member of the first component of the patient-specific jig is not engaged to said selected area or the second alignment structure is not engaged with the first alignment structure, reaming the acetabulum until the alignment member is engaged to said selected area and the second alignment structure is engaged with the first alignment structure; and 
 if the first alignment member is engaged to said selected area and the second alignment structure is engaged with the first alignment structure, thereby indicating information that an 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. 
 
     
     
         4 . A system for use in joint replacement surgery, the system comprising:
 an imaging machine configured to generate imaging data corresponding to an anatomic structure of a patient;   a patient-specific device generator configured to generate a model of a reamed surface of the anatomic structure of the patient and a first patient-specific jig image, the first patient-specific jig image including an outer component image and an inner component image; and   a patient-specific device converter configured to generate design control data to control operation of a machine for making a first patient-specific jig that corresponds to the generated first patient-specific jig image, the first patient-specific jig positionable against the anatomic structure of the patient at a position corresponding to an instillation position of a prosthesis implant.   
     
     
         5 . The system of  claim 4  wherein the outer component image includes a first alignment structure image configured to align with a second alignment structure image of the inner component image, the first and second alignment structure images configured such that alignment of the first alignment structure image with the second alignment structure image corresponds to a final installation position of a prostheses to be secured to the anatomic structure of the patient according to the imaging data. 
     
     
         6 . The system of  claim 5  wherein the outer component image includes a first alignment member image at a position on the outer component image corresponding to a selected area of the anatomic structure of the patient determined from the imaging data. 
     
     
         7 . The system of  claim 4  wherein the inner component image includes an aperture image, the aperture image extending from a distal end of the inner component image to a proximal end of the inner component image. 
     
     
         8 . The system of  claim 7  wherein:
 the distal end of the inner component image is a reference end that matches the model of the reamed surface of the anatomic structure of the patient; and 
 wherein the aperture image aligns with an orientation of a guide post according to a final installation position of a prostheses. 
 
     
     
         9 . The system of  claim 8  wherein:
 the patient-specific device generator is configured to generate a guide post image; 
 the distal end of the inner component image is a reference end that matches the model of the reamed surface of the anatomic structure of the patient; and 
 the aperture image aligns with an orientation of the guide post image.