Mill and guide apparatus for preparation of a hip prosthesis

Abstract

A guide apparatus for preparing the femur of a patient with a rotary mill to receive a femoral hip prosthesis includes a V-shaped guide body having a lower end base portion adapted to extend into the intermedullary canal of the femur and an upper end portion comprised of at least two spaced apart struts so that the overall guide body had a configuration substantially the same as the prosthesis body sought to be implanted in the patient. The lower end of the guide body base provides one or more hemispherical receptacles for holding the hemispherical end portion of a spinning mill bit. A preferably removable transverse guide rail has connection pins at one end portion thereof for forming a connection with the upper end of the guide body at one of the struts, the arm having a curved surface that is adapted to guide the mill bit during preparation of the intermedullary canal of the patient's femur for receiving a hip prosthesis thereafter.

What is claimed as invention is:  
     
       1. A guide apparatus for preparing the femur of a patient with a mill to receive a femoral hip prosthesis comprising: 
       a) a guide body having a lower end base, the guide body being connectable to adapted to extend into the intermedullary canal of the  a patient's femur during use, and having an upper end portion comprised of at least one strut;  
       b) the lower end of the base having  guide body including receptacle means for holding one end of  a spinning mill;  
       c) a  at least a partially curved transverse guide rail having connection means thereon for forming a connection with the upper end of the guide body, the rail having a  at least a partially curved surface that is adapted to guide the mill during preparation of the intermedullary  intramedullary canal of the patient's femur for receiving a hip prosthesis.  
     
     
       2. The apparatus of  claim 1  wherein the guide body comprises a base with a pair of struts extending upwardly therefrom. 
     
     
       3. The apparatus of  claim 2  further comprising a receptacle formed on the upper end portion of the guide body for receiving the connection means portion of the guide rail. 
     
     
       4. The apparatus of  claim 1  wherein the connection forming means comprises a reversible connector that attached the guide rail to the guide body in multiple positions. 
     
     
       5. The apparatus of  claim 1  wherein the guide body is V-shaped and includes medial and lateral spaced apart struts. 
     
     
       6. The apparatus of  claim 5  wherein the connection means forms a connection with the medial strut. 
     
     
       7. The apparatus of  claim 5  wherein the connection means comprises a receptacle carried by one of the struts of the V-shaped body, and a pair of opposed pegs carried by one end portion of the guide rail for respectively attaching the guide rail to the guide body and pre-selected left and right respective positions so that the guide rail can be used to form posterior and anterior sides of the intermedullary  intramedullary canal. 
     
     
       8. The apparatus of  claim 5  wherein the V-shaped guide body includes a pair of spaced apart struts including a generally vertically upstanding strut and inclined strut forming an acute angle therewith. 
     
     
       9. The apparatus of  claim 5  wherein the guide body defines an envelope having a shape corresponding to the shape of an upper end portion of the prosthesis body to be placed in the patient's femur. 
     
     
       10. The apparatus of  claim 1  wherein the receptacle means includes a pair of spaced apart, anterior and posterior receptacles each being sized to receive the lower end portion of the mill. 
     
     
       11. The apparatus of  claim 1  wherein the guide body defines an envelope having substantially the same configuration as the prosthesis body sought to be implanted in the patient. 
     
     
       12. The apparatus of  claim 1  wherein the guide rail includes a curved arm portion having a bearing surface thereon which allows the mill to track and  an arcuate path extending generally away from the central axis of the intermedullary  intramedullary canal so that the mill forms a cut in the intermedullary  intramedullary canal that increases the size of the intermedullary  intramedullary canal from the distal end portion thereof to the proximal end portion thereof. 
     
     
       13. The apparatus of  claim 1  wherein the guide rail includes a cantilevered arm portion extending away from the connection means, the cantilevered arm carrying a curved guide surface that is positioned to engage the mid-section of the mill during use. 
     
     
       14. A guide apparatus for preparing the femur with a mill to receive a hip prosthesis comprising: 
       a) a V-shaped guide body having substantially the same configuration as a corresponding hip prosthesis to be implanted, said guide body including a lower end base configured to extend at least partially into the intermedullary  intramedullary canal of the femur, and an upper end portion comprised of a pair of spaced apart struts forming a V-shaped configuration;  
       b) an elongated mill having a lower end portion with a hemispherical tip thereon and circumferentially spaced apart cutter blades extending between the hemispherical tip and at least a mid-section of the mill, and an upper end portion of the mill having a tooled end portion to receive a rotary drill for rotating the bit;  
       c) the lower end of the base having receptacle means for holding the end of a spinning mill bit;  
       d) a curved guide rail having connection means thereon for forming a connection with one of said struts, said guide rail having an arm extending substantially transverse to said struts, said arm having a curved surface that is adapted to guide the reamer bit during  therealong as the hemispherical tip pivots in said receptacle means thereby preparing the intermedullary  intramedullary canal for receipt of the hip prosthesis.  
     
     
       15. A guide apparatus for preparing the femur of a patient with a mill to receive a femoral hip prosthesis, comprising: 
         a )  a guide body having an upper end portion and a lower end portion, the guide body being connectable to a patient's femur, forming a connection therewith during use;    
         b )  the guide body including means for holding a spinning mill during a cutting of the patient's femur at the intramedullary canal of the femur;    
         c )  an at least partially curved guide rail portion that extends generally transversely with respect to the mill, the rail having means for forming a connection with the upper end portion of the guide body, the rail having a surface that is adapted to guide the mill during preparation of the intramedullary canal of the patient's femur for receiving a hip prosthesis.   
     
     
       16. A method of for preparing the femur of a patient with a mill to receive a femoral hip prosthesis, comprising the steps of: 
         a )  attaching a guide body having an upper end portion and a lower end portion to the patient's femur, forming a connection therewith;    
         b )  supporting a spinning mill upon the guide body during a cutting of the patient's femur at the intramedullary canal of the patient's femur;    
         c )  cutting the patient's bone tissue at the intramedullary canal using the spinning mill;    
         d )  guiding transverse movement of the spinning mill during cutting of the patient's bone tissue at the intramedullary canal of the patient's femur with a guide rail portion that extends generally transversely with respect to the mill, the rail being connected during use to the guide body, the rail having a surface that is adapted to guide the mill during preparation of the intramedullary canal of the patient's femur for receiving a hip prosthesis.   
     
     
       17. The method of  claim 16  wherein the rail is removably attachable to the guide body. 
     
     
       18. The method of  claim 17  wherein in step “a” the lower end of the guide body is attached to the patient's femur. 
     
     
       19. The method of  claim 16  wherein in step “b” the mill extends partially into the patient's femur during cutting thereof. 
     
     
       20. The method of  claim 16  wherein the rail prevents excess cutting of bone tissue by the mill by limiting transverse movement of the mill. 
     
     
       21. The method of  claim 16 , wherein the mill is generally aligned with the central longitudinal axis of the patient's intramedullary canal.