Method of Humeral Head Resurfacing and/or Replacement and System for Accomplishing the Method

Abstract

A method, and devices for facilitating the method, for shoulder replacement surgery. The method entails establishing a mechanical support in a the anatomical neck plane of the proximal humeral head, fixing a jig to the mechanical support, where the jig supports a drill guide with its axis perpendicular to the anatomical neck plane, adjusting the drill guide it coincide with the axis of the humeral head, drilling a hole through the humeral head for insertion of a shaft which will support and rotate a reaming bit. The reaming bits used to resurface the humeral head and the glenoid fossa are inserted through the back of the patient, through a gap created between two easily separated muscles, rather than through a gap cut through the subscapularis muscle on the front of the joint. A suitable jig is provided to facilitate the method.

I claim: 
     
         1 . A method of performing surgery on a shoulder joint of a patient, said method comprising the steps of:
 passing a first reamer head into the shoulder joint through a gap formed by retraction between an infraspinatus muscle and a teres minor muscle, without cutting a subscapularis muscle, the infraspinatus muscle, the teres minor muscle, or tendons attaching these muscles to a humerus;   operating the reamer to prepare a surface of the shoulder joint for application of a prosthesis to the surface;   passing a first shoulder joint prosthesis into the shoulder joint through the gap between the infraspinatus muscle and the teres minor muscle, without cutting a subscapularis muscle, the infraspinatus muscle, the teres minor muscle, or tendons attaching these muscles to a humerus; and   securing the shoulder joint prosthesis to a surface of the shoulder joint.   
     
     
         2 . A method of replacing a portion of a humeral head of a gleno-humeral joint of the patient with a humeral head prosthesis, said method comprising the steps of:
 removing a portion of the humeral head;   creating a channel through the humeral head, passing from a lateral area of the humerous to the apex of the humerus, along an axis of the humeral head;   providing a humeral head prosthesis comprising:
 a ball configured to replace the portion of a humeral head of the patient; 
 an anchoring bolt; 
 a stem with a first end configured for attachment to the ball and a second end configured for attachment to the anchoring bolt; 
   inserting the ball into place within the gleno-humeral joint;   inserting the stem into the channel, and joining the first end of the stem to the ball after the ball has been inserted into the gleno-humeral joint; and   securing the anchoring bolt to the second end of the stem, in a lateral area of the humerus.   
     
     
         3 . The method of  claim 2 , wherein the step of inserting the ball into place within the gleno-humeral joint is performed without cutting muscles overlying the gleno-humeral joint. 
     
     
         4 . The method of  claim 2 , further comprising the step of:
 placing a plate against the lateral surface of the humerus to provide support for the anchoring bolt.   
     
     
         5 . A method of replacing a portion of a glenoid fossa of a gleno-humeral joint of the patient with a glenoid prosthesis, said method comprising the steps of:
 removing a portion of the glenoid fossa;   providing a glenoid prosthesis comprising a keel;   creating a channel through a humeral head of the patient, passing from a lateral area of the humerus to the apex of the humerus, along an axis of the humeral head;   drilling a first pilot hole in the glenoid fossa to receive the keel of glenoid prosthesis, using a drill bit passing through the channel;   inserting the glenoid prosthesis into place within the gleno-humeral joint;   securing the glenoid prosthesis to the glenoid fossa by inserting the keel into the pilot hole.   
     
     
         6 . The method of  claim 5 , wherein the step of inserting the glenoid prosthesis into place within the gleno-humeral joint is performed without cutting muscles overlying the gleno-humeral joint. 
     
     
         7 . The method of  claim 5 , further comprising the steps of:
 drilling a second pilot hole in the glenoid fossa, using a drill bit passing through the channel;   further securing the glenoid prosthesis to the glenoid fossa by driving screws through the glenoid prosthesis and into the second pilot hole, using a screw driver inserted through the channel.   
     
     
         8 . A humeral head prosthesis for installation into a gleno-humeral joint of a patient, said humeral head prosthesis comprising:
 a ball configured to replace the portion of a humeral head of the patient;   an anchoring bolt; and   a stem with a first end configured for attachment to the ball and a second end configured for attachment to the anchoring bolt;   wherein the ball, anchoring bolt and stem are configured as separate components, and configured for assembly after the ball is inserted into the gleno-humeral joint of the patient.