Cutting guide apparatus and surgical method for use in knee arthroplasty

Abstract

Novel cutting guides and surgical methods for use in knee arthroplasty are described. Embodiments of the inventive cutting guide apparatus include fixed and adjustable cutting guide blocks having a series of slots designed to accommodate a cutting saw. The cutting guides and surgical method are designed to allow for the provision of all desired surgical cuts upon the distal end of the femur, for subsequent implantation of a prosthesis thereto, without having to remove the cutting guide block.

1 . An orthopedic cutting guide apparatus suitable for use in preparing the distal end of a femur in knee arthroplasty, said femur having an anterior surface, a posterior surface, and a distal-most end surface, said apparatus comprising:
 a. an adjustable cutting guide block comprising a first section secured to a second section; said first and second sections each comprising at least one cutting slot for engaging a cutting saw for the provision of cuts at desired locations upon said femur in preparation of said femur for attachment of a prosthetic implant thereto;   b. said first section of said cutting guide further comprising an anterior face integral with a proximal end, a distal face integral with a posterior end, and medial and lateral sides;   c. said second section comprising a distal face, an anterior end, a posterior end, and medial and lateral sides; and   d. an insert configured to engage said first and second sections of said cutting guide block to one another, wherein said insert has one side configured to engage said posterior end of said first section and an opposite side configured to engage said anterior end of said second section. whereby said insert may be engaged between said posterior end of said first section and said anterior end of said second section to provide for adjustability of said cutting guide upon said femur in the anterior/posterior direction with respect to said femur.   
     
     
         2 . The apparatus of  claim 1 , further including at least on stabilizing pin for securing said block to said femur. 
     
     
         3 . The apparatus of claim of  1 , wherein said posterior end of said first section comprises at least one elongated channel configured to engage therein a complementarily configured first rib extending on one surface of said insert; and wherein said anterior end of said second section comprises at least one elongated channel configured to engage therein a complementarily configured second rib extending on another surface of said insert; whereby when said ribs of said insert are engaged within said channels of said first and second sections, said first and second sections of said cutting guide block are secured to one another at a desired length in the anterior/posterior direction with respect to said femur. 
     
     
         4 . The apparatus of  claim 1 , wherein said insert is further configured to engage a second insert, such that two or more inserts may be stacked upon one another and engaged between said posterior end of said first section and said anterior end of said second section. 
     
     
         5 . The apparatus of  claim 2 , wherein said stabilizing pin comprises a head and an elongated shank integral with said head and having a penetrating point for piercing bone, said pin further having a spherical portion subjacent said head and configured for pivotal engagement within a complementarily configured bore communicating through said cutting guide block. 
     
     
         6 . The apparatus of  claim 5 , wherein cutting guide block further comprises at least one stabilizing lug for engaging said stabilizing pin, said lug extending from one of said medial and lateral sides of said cutting guide block, said lug comprising said bore for engaging said stabilizing pin. 
     
     
         7 . The apparatus of  claim 2 , wherein said stabilizing pin comprises a head and an elongated shank integral with said head and having a penetrating point for piercing bone, said pin further having a substantially triangularly-shaped portion subjacent said head and configured for pivotal engagement within a complementarily configured bore communicating through said guide. 
     
     
         8 . A surgical method for shaping the distal end of a femur for subsequent implantation of a prosthesis in knee arthroplasty, said femur having an anterior surface, a distal-most end surface, and a posterior surface, said method comprising:
 a. aligning a cutting guide block on said distal end of said femur;   b. securing said cutting guide block to said distal end of said femur, said cutting guide block comprising a series of slots communicating therethrough, each of said slots designed to accommodate a cutting blade of a saw, each slot oriented on said guide to provide corresponding cuts on the anterior, distal-most, and posterior surfaces of said femur;   c. making at least five successive cuts into said femur by inserting said saw blade into each of said cutting slots of said cutting guide in any order desired, wherein all of said five cuts are made without removing or repositioning said cutting guide and wherein one of said cuts is a distal-most cut made into said distal-most end of said femur; and   d. removing said cutting guide block from said femur for subsequent implantation of a knee prosthesis.   
     
     
         9 . The method of  claim 8 , wherein said cutting guide block is the cutting guide block of  claim 1 . 
     
     
         10 . The method of  claim 8 , wherein said cutting guide block is adjustable in the anterior/posterior direction relative to said distal end of said femur. 
     
     
         11 . The method of  claim 8 , wherein one of one said successive cuts is an anterior chamfered cut made through a corresponding slot communicating through said anterior portion of said cutting guide, thereby providing said anterior chamfered cut via the anterior side said femur. 
     
     
         12 . The method of  claim 8 , wherein said aligning of said cutting guide block does not include the insertion of an intramedullary guide into said femur prior to alignment. 
     
     
         13 . The method of  claim 8 , wherein said aligning further includes the insertion of spacers through a slot within said cutting guide block and beneath the posterior surface of said femur. 
     
     
         14 . The method of  claim 8 , wherein said cutting guide block is aligned on said distal end of said femur via a computer assisted orientation system operatively connected to said cutting guide block. 
     
     
         15 . The method of  claim 8 , wherein securing of said cutting guide block to said femur further includes engaging a stabilizing a pin within bores penetrating through medial and lateral sides of said cutting guide block and within a bore drilled through said respective medial and lateral sides of said distal femur, said femoral bore in registration with said bores of said cutting guide block.