Patient-specific pelvic implants for acetabular reconstruction

Abstract

A pelvic implant includes a first surface including a recess configured for receiving a portion of a flange of an acetabular cage and a patient-specific second surface opposite to the first surface. The patient-specific second surface is preoperatively configured from a three-dimensional digital image of a pelvis of a patient to mate and closely conform to a corresponding surface of the pelvis under the flange in only one position.

1 . A pelvic implant system comprising:
 an acetabular cage implantable into a pelvis of a patient; the acetabular cage including an acetabular cup, and an iliac flange and an ischial flange coupled to an upper portion of the acetabular cup; and   an iliac spacer and an ischial spacer, wherein each of the iliac and ischial spacers comprises first and second opposing surfaces, and a peripheral surface located between and to space apart the first and second surfaces to provide at least one of the iliac and ischial spacers with a wedge shape, wherein each of the first surfaces is shaped to receive a complementary-shaped portion of a corresponding flange of at least one flange of the iliac and ischial flanges, wherein each of the second surfaces defines a patient-specific bone-engaging surface preoperatively configured from a three-dimensional image of the pelvis to complementary mate and closely conform to a surface of the pelvis under the flange in one position.   
     
     
         2 . The pelvic implant system of  claim 21 , wherein each of the peripheral surfaces includes a ridge surrounding each of the recesses that are elevated relative to each of the first surfaces. 
     
     
         3 . (canceled) 
     
     
         4 . (canceled) 
     
     
         5 . The pelvic implant system of  claim 21 , wherein at least the iliac flange includes a substantially square shape or square-like shape. 
     
     
         6 . The pelvic implant system of  claim 5 , wherein the recess of the iliac spacer has an elongated rectangular shape. 
     
     
         7 . The pelvic implant system of  claim 5 , wherein the recess of the iliac spacer has a square shape. 
     
     
         8 . The pelvic plant system of  claim 21 , wherein the recess of the ischial spacer as a triangular shape. 
     
     
         9 . The pelvic implant system of  claim 1 , wherein at least one flange of the iliac and ischial flanges is removably coupled to the acetabular cup. 
     
     
         10 . The pelvic implant system of  claim 9 , wherein the at least one flange of the iliac and ischial flanges that is removably coupled to the acetabular cup is an ischial blade modularly coupled to the acetabular cup. 
     
     
         11 . The pelvic implant system of  claim 1 , further comprising:
 an obturator foramen hook modularly coupled to the acetabular cup.   
     
     
         12 . The pelvic implant system of  claim 1 , wherein the iliac spacer includes a plurality of iliac spacers, wherein each iliac spacer of the plurality of iliac spacers includes a height different from the other iliac spacers such that the plurality of iliac spacers has a variable height. 
     
     
         13 . A pelvic implant system comprising:
 a patient-specific spacer having:   a first surface with a recess configured for receiving at least a portion of a flange of an acetabular cage, wherein the acetabular cage is configured to be placed in an acetabular socket of a pelvis;   a patient-specific second surface opposite to and spaced apart from the first surface, the patient-specific second surface preoperatively configured from a three-dimensional digital image of the pelvis to have a mirror surface that complementary mates and closely conforms to a surface of the pelvis under the flange in only one position on the pelvis; and   a peripheral surface located between the first surface and the patient-specific second surface such that the first surface and the patient-specific second surface are angled relative to each other such that the patient-specific spacer has a substantially wedge shape.   
     
     
         14 . The pelvic implant system of  claim 13 , wherein the patient-specific spacer includes a plurality of patient-specific spacers, wherein each of the patient-specific spacers includes a peripheral surface that has a height; wherein the height of each patient-specific spacer is different from each of the other patient-specific spacers, such that the plurality of patient-specific spacers has a variable height. 
     
     
         15 . The pelvic implant system of  claim 14 , wherein each of the plurality of patient-specific spacers includes a recess that is at least one of triangle-shaped, elongated rectangle-shaped, substantially square-shaped, or square-shaped. 
     
     
         16 . The pelvic implant system of  claim 15 , wherein the recesses are configured for at least one ischial flange and at least one iliac flange. 
     
     
         17 .- 20 . (canceled) 
     
     
         21 . The pelvic implant system of  claim 1 , wherein each of the first surfaces has a recess configured to receive the complementary-shaped portion of the corresponding flange. 
     
     
         22 . The pelvic implant system of  claim 1 , wherein the acetabular cup has a rim that lies substantially in a plane, wherein the iliac flange and the ischial flange are angled away from the acetabular cup relative to the plane. 
     
     
         23 . The pelvic implant system of  claim 22 , wherein the wedge shape of the at least one of the iliac and ischial spacers has a wide end and a narrow end, and the narrow end is disposed proximate the acetabular cup and the wide end is disposed distal to the acetabular cup. 
     
     
         24 . The pelvic implant system of  claim 2 , wherein:
 a thickness of the iliac spacer is greater than a thickness of the iliac flange and a surface area of the iliac spacer is greater than a surface area of the iliac flange; and   a thickness of the ischial spacer is greater than a thickness of the ischial flange and a surface area of the ischial spacer is greater than a surface area of the ischial flange.   
     
     
         25 . The pelvic implant system of  claim 13 , wherein the patient-specific spacer includes a plurality of fixation holes extending from the first surface to the patient-specific second surface. 
     
     
         26 . The pelvic implant system of  claim 13 , wherein the peripheral surface includes a ridge surrounding the recess that is elevated relative to the first surface.