Marking template for installing a custom replacement device for resurfacing a femur and associated installation method

Abstract

A replacement device for resurfacing a joint surface of a femur and a method of making and installing such a device is provided. The custom replacement device is designed to substantially fit the trochlear groove surface, of an individual femur, thereby creating a “customized” replacement device for that individual femur and maintaining the original kinematics of the joint. The top surface is designed so as to maintain centrally directed tracking of the patella perpendicular to the plane established by the distal end of the femoral condyles and aligned with the center of the femoral head.

We claim: 
     
         1 . A knee prosthesis kit comprising:
 a knee prosthesis custom formed based on preoperative data obtained from a patient, the knee prosthesis configured to substantially allow the original kinematics of the patient's knee; and   an instrument comprising:
 a knee contacting surface with a three-dimensional shape custom formed based on the preoperative data to align with at least a portion of the patient's trochlear groove and to fit at least a portion of the patient's femur; and 
 a surgical tool guide customized for the patient. 
   
     
     
         2 . The kit according to  claim 1 , wherein the three-dimensional shape of the knee contacting surface of the instrument is configured to fit at least a portion of a distal-anterior region of the patient's femur. 
     
     
         3 . The kit according to  claim 1 , wherein the knee prosthesis is configured to maintain the original articulating movement of the patient's knee. 
     
     
         4 . The kit according to  claim 1 , wherein the knee contacting surface of the instrument is sized based on a location of a ridge of the patient's lateral condyle and a location of a ridge of the patient's medial condyle. 
     
     
         5 . The kit according to  claim 4 , wherein the knee contacting surface of the instrument is further sized based on a point of attachment of the patient's anterior cruciate ligament and a superior edge of an end of the patient's natural cartilage in the trochlea. 
     
     
         6 . The kit according to  claim 1 , wherein the knee prosthesis is configured to substantially maintain the original kinematics of the patient's knee after removal of at least some bone from the patient's knee. 
     
     
         7 . The kit according to  claim 1 , wherein the preoperative data comprises CT scan data. 
     
     
         8 . The kit according to  claim 1 , wherein the knee prosthesis is a femoral prosthesis. 
     
     
         9 . The kit according to  claim 1 , wherein the surgical tool guide is custom formed based on the preoperative data. 
     
     
         10 . The kit according to  claim 9 , wherein the surgical tool guide is in a predetermined position with respect to the three-dimensional shape of the knee contacting surface of the instrument. 
     
     
         11 . The kit according to  claim 1 , wherein the surgical tool guide comprises at least one opening for drilling a hole for attaching the knee prosthesis to the patient's knee. 
     
     
         12 . A knee prosthesis kit comprising:
 a knee prosthesis custom formed based on preoperative data obtained from a patient, the knee prosthesis configured to substantially preserve the original kinematics of the patient's knee after removal of at least some bone from the patient's knee; and   an instrument comprising a knee contacting surface with a three-dimensional shape custom formed based on the preoperative data to fit at least a portion of the patient's femur.   
     
     
         13 . The kit according to  claim 12 , wherein the knee contacting surface of the instrument is configured to align with at least a portion of the patient's trochlear groove. 
     
     
         14 . The kit according to  claim 12 , wherein the three-dimensional shape of the knee contacting surface of the instrument is configured to fit at least a portion of a distal-anterior region of the patient's femur. 
     
     
         15 . The kit according to  claim 12 , wherein the knee prosthesis is configured to maintain the original articulating movement of the patient's knee. 
     
     
         16 . The kit according to  claim 12 , wherein the knee contacting surface of the instrument is sized based on a distance between a ridge of the patient's lateral condyle and a ridge of the patient's medial condyle. 
     
     
         17 . The kit according to  claim 16 , wherein the knee contacting surface of the instrument is further sized based on a distance between a point of attachment of the patient's anterior cruciate ligament and a superior edge of an end of the patient's natural cartilage in the trochlea. 
     
     
         18 . The kit according to  claim 12 , wherein the preoperative data comprises CT scan data. 
     
     
         19 . The kit according to  claim 12 , wherein the knee prosthesis is a femoral prosthesis. 
     
     
         20 . The kit according to  claim 12 , wherein the instrument further comprises a surgical tool guide custom formed based on the preoperative data to be in a predetermined position with respect to the three-dimensional shape of the knee contacting surface of the instrument. 
     
     
         21 . The kit according to  claim 16 , wherein the surgical tool guide comprises at least one opening for drilling a hole for attaching the knee prosthesis to the patient's knee. 
     
     
         22 . A knee prosthesis kit comprising:
 a knee prosthesis custom formed based on preoperative data obtained from a patient, the knee prosthesis configured to maintain the original articulating movement of the patient's knee after removal of at least some bone from the patient's knee; and   an instrument comprising a knee contacting surface with a three-dimensional shape custom formed based on the preoperative data to fit at least a portion of the patient's femur.   
     
     
         23 . The kit according to  claim 22 , wherein the knee contacting surface of the instrument is configured to align with at least a portion of the patient's trochlear groove. 
     
     
         24 . The kit according to  claim 22 , wherein the three-dimensional shape of the knee contacting surface of the instrument is configured to fit at least a portion of a distal-anterior region of the patient's femur. 
     
     
         25 . The kit according to  claim 22 , wherein the knee contacting surface of the instrument is sized based on a distance between a ridge of the patient's lateral condyle and a ridge of the patient's medial condyle. 
     
     
         26 . The kit according to  claim 25 , wherein the knee contacting surface of the instrument is further sized based on a distance between a point of attachment of the patient's anterior cruciate ligament and a superior edge of an end of the patient's natural cartilage in the trochlea. 
     
     
         27 . The kit according to  claim 22 , wherein the preoperative data comprises CT scan data. 
     
     
         28 . The kit according to  claim 22 , wherein the knee prosthesis is a femoral prosthesis. 
     
     
         29 . The kit according to  claim 22 , wherein the instrument further comprises a surgical tool guide custom formed based on the preoperative data to be in a predetermined position with respect to the three-dimensional shape of the knee contacting surface of the instrument. 
     
     
         30 . The kit according to  claim 29 , wherein the surgical tool guide comprises at least one opening for drilling a hole for attaching the knee prosthesis to the patient's knee.