Device and method for bicompartmental arthroplasty

Abstract

Disclosed is a device and method of bicompartmental arthroplasty of the knee. The device permits arthroplasty of the medial or lateral and patellofemoral compartments of the knee while leaving the opposite compartments and the anterior and posterior cruciate ligaments intact. The device provides a femoral prosthesis component that includes a trochlear surface and a tibial prosthesis component which can be secured to the tibia. The femoral component is essentially “u” shaped having an anterior leg upon which the trochlear surface is positioned and a posterior leg which engages the posterior surface of the distal end of the femur. The femoral component also has a convex articulating surface which engages a concave articulating surface of the tibial prosthesis component to approximate the articulation of a healthy knee. The patellar prosthesis is applied to the posterior surface of the patella and articulates with the trochlear exterior surface of the femur.

1 . A method of performing bicompartmental arthroplasty of a patient's knee comprising the steps of: 
 a. making an incision along the anterior medial aspect of the knee;    b. excising the remnants of the medial meniscus;    c. surgically preparing a medial compartment of a proximal end of the patient's tibia to receive a medial tibial prosthesis component in a manner so as to preserve the integrity of a anterior and posterior cruciate ligaments; said medial tibial prosthesis component having a first surface configured to be secured to said surgically prepared medial compartment of the proximal end of the patient's tibia and a second concave curved surface;    d. rotating a patella approximately 90 degrees;    e. surgically preparing a medial compartment of a distal end of the patient's femur to receive a medial femoral prosthesis component having a concave trochlea surface; said medial femoral prosthesis component also having a first surface configured to be secured to said surgically prepared medial compartment of the distal end of the femur and a second convex curved surface configured to articulate with the second concave curved surface of said medial tibial prosthesis component to permit pivotal articulation between said medial femoral prosthesis component and said medial tibial prosthesis component, said pivotal articulation approximating the articulation of a healthy knee joint;    f. securing a medial femoral component to the femur;    g. securing the medial tibial component to the tibia;    h. positioning the patella over the concave trochlea surface of the medial femoral prosthesis component; and    i. closing the incision.    
   
   
       2 . A method of performing bicompartmental arthroplasty of the knee as claimed in  claim 1 , further comprising the additional steps of: 
 a. surgically preparing a posterior surface of the patient's patella to receive a patella prosthesis component having a first surface configured to be secured to said surgically prepared posterior surface of the patella, and a convex curved second surface configured to engage the concave trochlea surface of said medial femoral prosthesis component; and    b. securing said patella prosthesis component to the patella.    
   
   
       3 . A method for bicompartmental arthroplasty of the knee as claimed in  claim 1  wherein said medial femoral prosthesis component comprises a metallic material.  
   
   
       4 . A method for bicompartmental arthroplasty of the knee as claimed in  claim 1  wherein said medial femoral prosthesis component comprises a bio-compatible plastic.  
   
   
       5 . A method for bicompartmental arthroplasty of the knee as claimed in  claim 1  wherein said medial tibial prosthesis component comprises a bio-compatible plastic.  
   
   
       6 . A method for bicompartmental arthroplasty of the knee as claimed in  claim 1  wherein said medial tibial prosthesis component comprises a metallic material.  
   
   
       7 . A method for bicompartmental arthroplasty of the knee as claimed in  claim 1  wherein said medial tibial prosthesis component comprises a bio-compatible plastic and metallic material.  
   
   
       8 . A method for bicompartmental arthroplasty of the knee as claimed in  claim 1  wherein said medial femoral prosthesis component and said medial tibial prosthesis component are dimensioned to permit the distal end of the femur and the proximal end of the tibia to be surgically prepared in manner so as to preserve the integrity of the patient's anterior and posterior cruciate ligaments.  
   
   
       9 . A method for bicompartmental arthroplasty of the knee as claimed in  claim 2  further comprising the additional step of: 
 positioning said convex curved second surface of said patella prosthesis component to articulate with the concave trochlea surface of said medial femoral prosthesis component.    
   
   
       10 . A method for bicompartmental arthroplasty of the knee as claimed in  claim 1  wherein said femoral prosthesis component is secured to the femur using a cement.  
   
   
       11 . A method for bicompartmental arthroplasty of the knee as claimed in  claim 1  wherein said femoral prosthesis component is secured to the femur by bone ingrowth into an ingrowth surface applied to the first surface of the femoral prosthesis component.  
   
   
       12 . A method for bicompartmental arthroplasty of the knee as claimed in  claim 1  wherein said tibial prosthesis component is secured to the tibia using a cement.  
   
   
       13 . A method for bicompartmental arthroplasty of the knee as claimed in  claim 1  wherein said tibial prosthesis component is secured to the tibia by bone ingrowth into an ingrowth surface applied to the first surface of the tibial prosthesis component.  
   
   
       14 . A method for bicompartmental arthroplasty of the knee as claimed in  claim 2  wherein said patella prosthesis component is secured to the patella by cement.  
   
   
       15 . A method for bicompartmental arthroplasty of the knee as claimed in  claim 2  wherein said patella prosthesis component is secured to the patella by bone ingrowth into an ingrowth surface applied to the first surface of the patella prosthesis component.  
   
   
       16 . A method of performing bicompartmental arthroplasty of a patient's knee comprising the steps of: 
 a. making an incision along an anterior medial aspect of the knee;    b. excising remnants of a medial meniscus;    c. surgically preparing a medial compartment of a proximal end of a patient's tibia to receive a medial tibial prosthesis component in a manner so as to preserve the integrity of anterior and posterior cruciate ligaments; said medial tibial prosthesis component having a first surface configured to be secured to said surgically prepared medial compartment of the proximal end of the tibia and a second concave curved surface;    d. rotating the patient's patella approximately 90 degrees;    e. surgically preparing the medial compartment of a distal end of the patient's femur to receive a medial femoral prosthesis component, said medial femoral prosthesis component having a first leg portion and a second leg portion and a base portion connected between said first and second leg portions to form an essentially U-shaped component, said medial femoral prosthesis component having a first interior surface configured to be secured to a surgically prepared medial compartment of a distal end of the patient's femur so that a base portion of the femoral prosthesis contacts the distal end of the femur, said first leg portion contacts the anterior surface of the distal end of the femur, and the second leg portion contacts the posterior surface of the distal end of the femur, and said medial femoral prosthesis component also having a second exterior convex curved surface on said base portion, and an exterior concave trochlea surface positioned on said first leg portion and configured to articulate with the patella; said second convex curved surface on said base portion configured to articulate with the second concave curved surface of said medial tibial prosthesis component to permit articulation between said medial femoral prosthesis component and said medial tibial prosthesis component, said articulation motion approximating the articulation of a healthy knee joint;    f. securing the medial femoral component to the femur;    g. securing the medial tibial component to the tibia;    h. positioning the patella over the trochlea surface of the medial femoral prosthesis component; and    i. closing the incision.    
   
   
       17 . A method of performing bicompartmental arthroplasty of the knee as claimed in  claim 16  comprising the additional steps of: 
 a. surgically preparing a posterior surface of the patient's patella to receive a patella prosthesis component having a first surface configured to be secured to said surgically prepared posterior surface of the patella, and a convex curved second surface configured to engage the concave trochlea surface of said medial femoral prosthesis component; and    b. Securing said patella prosthesis component to the patella.    
   
   
       18 . A method for bicompartmental arthroplasty of the knee as claimed in  claim 16  wherein said medial femoral prosthesis component comprises a metallic material.  
   
   
       19 . A method for bicompartmental arthroplasty of the knee as claimed in  claim 16  wherein said medial femoral prosthesis component comprises a bio-compatible plastic.  
   
   
       20 . A method for bicompartmental arthroplasty of the knee as claimed in  claim 16  wherein said medial tibial prosthesis component comprises a bio-compatible plastic.  
   
   
       21 . A method for bicompartmental arthroplasty of the knee as claimed in  claim 16  wherein said medial tibial prosthesis component comprises a metallic material.  
   
   
       22 . A method for bicompartmental arthroplasty of the knee as claimed in  claim 16  wherein said medial tibial prosthesis component comprises a bio-compatible plastic and metallic material.  
   
   
       23 . A method for bicompartmental arthroplasty of the knee as claimed in  claim 16  wherein said medial femoral prosthesis component and said medial tibial prosthesis component are dimensioned to permit the distal end of the femur and the proximal end of the tibia to be surgically prepared in manner so as to preserve the integrity of the anterior and posterior cruciate ligaments.  
   
   
       24 . A method for bicompartmental arthroplasty of the knee as claimed in  claim 16  wherein said femoral prosthesis component is secured to the femur using a cement.  
   
   
       25 . A method for bicompartmental arthroplasty of the knee as claimed in  claim 16  wherein said femoral prosthesis component is secured to the femur by bone ingrowth into an ingrowth surface applied to the first surface of the femoral prosthesis component.  
   
   
       26 . A method for bicompartmental arthroplasty of the knee as claimed in  claim 16  wherein said tibial prosthesis component is secured to the tibia using a cement.  
   
   
       27 . A method for bicompartmental arthroplasty of the knee as claimed in  claim 16  wherein said tibial prosthesis component is secured to the tibia by bone ingrowth into an ingrowth surface applied to the first surface of the tibial prosthesis component.  
   
   
       28 . A method for bicompartmental arthroplasty of the knee as claimed in  claim 17  wherein said patella prosthesis component is secured to the patella by cement.  
   
   
       29 . A method for bicompartmental arthroplasty of the knee as claimed in  claim 17  wherein said patella prosthesis component is secured to the patella by bone ingrowth into an ingrowth surface applied to the first surface of the patella prosthesis component.  
   
   
       30 . A method for bicompartmental arthroplasty of the knee as claimed in  claim 17  further comprising the additional step of: 
 positioning said convex curved second surface of said patella prosthesis component to articulate with the concave trochlea surface of said medial femoral prosthesis component.