Apparatus for fitting a shoulder prosthesis

Abstract

Method and set of surgical instruments for fitting a shoulder prosthesis, and the shoulder prosthesis. The proposed method seeks to interpose a bone graft between the previously prepared glenoid surface of a scapula of a patient's shoulder and the face of a glenoid prosthetic component opposite the articular surface. The set of instruments permit the bone graft to be taken from the upper epiphysis of the humerus, either in situ or ex vivo.

1 . A shoulder prosthesis adapted for implantation in a glenoid of a patient, the prosthesis comprising:
 a head portion having an articulation surface adapted for articulation with a humeral head and an engagement surface opposite the articulation surface;   a bone graft having a medial surface and a distal surface and defining a thickness between the medial and distal surfaces, the medial surface having a shape complementary to the glenoid surface and the distal surface having a shape complementary to the engagement face of the head portion; and   an anchor structure connected to the engagement surface and adapted to extend through the bone graft and into the glenoid surface, the anchor structure being adjustable in overall length to accommodate the thickness of the bone graft such that the anchor structure extends through and projects beyond the bone graft upon engagement of the distal surface of the bone graft with the engagement surface of the head portion.   
     
     
         2 . The prosthesis of  claim 1 , wherein the bone graft is at least 7 mm thick. 
     
     
         3 . The prosthesis of  claim 1 , wherein the anchor structure is adjustable to at least 20 mm in length. 
     
     
         4 . The prosthesis of  claim 1 , wherein the anchor structure includes a first portion and a second portion telescopically received in the first portion, the second portion being extendable from the first portion to adjust the overall length of the anchor structure. 
     
     
         5 . The prosthesis of  claim 1 , wherein the anchor structure includes a first portion having a first length and a second portion releasably connected to the first portion to extend the overall length of the anchor structure. 
     
     
         6 . The prosthesis of  claim 1 , wherein the bone graft includes metal material having a trabecular structure. 
     
     
         7 . The prosthesis of  claim 1 , wherein the bone graft includes structured porous tantalum. 
     
     
         8 . The prosthesis of  claim 1 , wherein the bone graft is taken from a bone in the patient. 
     
     
         9 . The prosthesis of  claim 1 , wherein the bone graft comprises an upper epiphysis of a humerus. 
     
     
         10 . The prosthesis of  claim 1 , wherein the bone graft comprises at least one of an allograft, a xenograft, a natural material, and a synthetic material. 
     
     
         11 . The prosthesis of  claim 1 , wherein the bone graft defines an outer lateral face and the prosthesis further comprises a reinforcing structure that at least partially surrounds the outer lateral face of the bone graft. 
     
     
         12 . The prosthesis of  claim 1 , wherein the bone graft defines an outer lateral face and the glenoid component at least partially surrounds the outer lateral face of the bone graft. 
     
     
         13 . The prosthesis of  claim 1 , wherein the bone graft defines an outer lateral face and the prosthesis further comprises a reinforcing structure located between the medial surface of the bone graft and the glenoid surface, the first reinforcing structure comprising first side walls supporting the outer lateral face of the bone graft. 
     
     
         14 . A shoulder prosthesis system adapted for replacement of a glenohumeral joint of a patient, the prosthesis comprising:
 a humeral head having a humeral articulation surface; and   a glenoid component including:
 a head portion having an articulation surface in articulating engagement with the humeral articulation surface of the humeral head; 
 a bone graft having a medial surface and a distal surface and defining a thickness between the medial and distal surfaces; and 
 an anchor structure connected to the engagement surface and secured into a glenoid surface of the glenohumeral joint, the anchor structure engaging the bone graft and restricting lateral movement of the bone graft, the anchor structure being adapted to be adjusted in overall length to accommodate the thickness of the bone graft. 
   
     
     
         15 . The system of  claim 14 , wherein the anchor structure includes a first portion and a second portion, the second portion being telescopically received in the first portion and extendable from the first portion to adjust the overall length of the anchor structure. 
     
     
         16 . The system of  claim 14 , wherein the anchor structure includes a first portion and a second portion releasably secured to the first portion to extend the overall length of the anchor structure. 
     
     
         17 . A method of repairing a glenohumeral joint, the method comprising:
 receiving a bone graft with an anchor structure of a glenoid component, the bone graft having a thickness between a medial surface and a distal surface of the bone graft;   engaging the medial surface of the bone graft with an engagement surface of a head structure of the glenoid component, the head structure having an articulation surface that is adapted to articulate with a humeral head, the articulation surface being positioned opposite the engagement surface;   restricting lateral movement of the bone graft with the anchor structure of the glenoid component, the anchor structure of the glenoid component projecting from the engagement surface of the glenoid component;   adjusting an overall length of the anchor structure of the glenoid component to compensate for the thickness of the bone graft; and   securing the anchor structure of the glenoid component into a boney structure of the glenoid.   
     
     
         18 . The method of  claim 17 , further comprising engaging the articulation surface of the glenoid component with a natural humeral head. 
     
     
         19 . The method of  claim 17 , further comprising engaging the articulation surface of the glenoid component with a prosthetic humeral head. 
     
     
         20 . The method of  claim 17 , further comprising shaping a natural humeral head to define a humeral engagement surface and engaging the articulation surface of the glenoid component with the humeral engagement surface. 
     
     
         21 . The method of  claim 17 , wherein the anchor structure includes a first portion having a first length and a second portion releasably connected to the first portion to extend the overall length of the anchor structure, and further wherein the bone graft is received by the first portion and then the second portion is releasably connected to the first portion. 
     
     
         22 . The method of  claim 17 , wherein the bone graft is received by the engagement surface and then the first portion of the anchor structure is connected to the head structure.