Glenoid component with improved fixation stability

Abstract

A glenoid component is provided to reduce glenoid loosening when implanted in orthopedic joint replacement/reconstruction, such for a shoulder. The glenoid component can include pegs or a keel and articulating surface geometry that uses complex, non-spherical geometry to recreate a level of constraint that is adequate, but not excessive, to thereby mitigate loosening of the glenoid component after implantation. In addition, some embodiments provide that peak stresses both within cement and at an interface of the cement and a supportive component can be reduced. Further, geometry of the pegs can allow stresses to be evenly applied to a cement mantle formed in the supportive component. Finally, the pegs can be configured to desired lengths in order to avoid placement in areas of the supportive component, for example, that have insufficient bone stock.

1 .- 33 . (canceled) 
     
     
         34 . A method for implanting a glenoid component in a supportive substrate of a scapula, the method comprising the steps of:
 drilling at least one hole in the supportive substrate to facilitate press-fitting a proximal portion of at least one peg extending from a back surface of the glenoid component;   depositing cement in a distal portion of the hole in the supportive component;   press fitting the proximal portion of the at least one peg in a proximal portion of the at least one hole;   engaging a distal portion of the peg with the cement located in the distal portion of the hole in the supportive substrate; and   at least partially curing the cement so that at least one attachment structure located on a distal portion of the peg comprises a mechanically interlock with a cement mantle in the supportive substrate.   
     
     
         35 . The method of  claim 34  comprising configuring the distal portion of the peg with a maximum cross-sectional diameter relative to a longitudinal axis of the peg less than a minimum cross-sectional diameter of the proximal portion. 
     
     
         36 . The method of  claim 34  comprising the step of pressurizing the cement in the hole. 
     
     
         37 . The method of  claim 34  comprising injecting high pressure cement into the hole with, a tight fitting cement nozzle. 
     
     
         38 . The method of  claim 34  comprising the steps:
 inserting a hollow distal component comprising a material for bone in-growth into the hole; and 
 locking the distal portion peg into the hollow distal component to secure the peg to the supportive component. 
 
     
     
         39 . The method of  claim 34  comprising the steps of:
 forming a reverse curvature along least a portion of a peripheral region of a front surface of the glenoid component; and transmitting a load applied to the peripheral region by the humeral head downwardly through substantially all of the glenoid component and into the supportive substrate. 
 
     
     
         40 . The method of  claim 34  comprising the steps of:
 forming a reverse curvature along least a portion of a peripheral region of a front surface of the glenoid component; and 
 directing a load applied to the peripheral region by the humeral head through the back surface of the glenoid component and into the supportive substrate. 
 
     
     
         41 . The method of  claim 34  comprising the steps of:
 forming a reverse curvature along least a portion of a peripheral region of a front surface of the glenoid component; and 
 directing a load applied to the peripheral region by the humeral head to the supportive substrate engaged with the back surface of the glenoid component. 
 
     
     
         42 . The method of  claim 34  comprising the step of forming a reverse curvature along least a portion of a peripheral region of a front surface of the glenoid component that substantially eliminates overhanging loads. 
     
     
         43 . The method of  claim 34  comprising forming at least one contoured pathway in a front surface of the glenoid component that directs motion of a humeral head along a directional path. 
     
     
         44 . The method of  claim 34  comprising forming at least one eminence in a front surface of the glenoid component to discourage motion of a humeral head along the front surface. 
     
     
         45 . The method of  claim 34  comprising locating the cement mantle substantially along only the distal portion of the peg. 
     
     
         46 . The method of  claim 34  wherein the attachment structure is selected from the group comprising at least one of a radial groove, an annular groove, a linear groove, an axial groove, a step, a flute, radial holes, annular holes, and linear holes. 
     
     
         47 . The method of  claim 34  comprising:
 engaging a first peg of a first length with an the inferior region of the scapula; 
 engaging a second peg of a second length less than the first length with a central region, of the scapula; and 
 engaging a third peg of a third length less than the second length with a superior region of the scapula. 
 
     
     
         48 . A method for implanting a glenoid component in a supportive substrate of a scapula, the method comprising the steps of:
 providing a supportive structure comprising at least one hole to receive a portion of at least one peg extending from a back surface of the glenoid component;   depositing cement in a distal portion of the hole in the supportive component;   press fitting the proximal portion of the at least one peg in a proximal portion of the at least one hole; and   engaging a distal portion of the peg with the cement located in the distal portion of the hole in the supportive substrate.   
     
     
         49 . The method of  claim 48 , wherein providing the supportive structure comprises forming the at least one hole in the supportive structure. 
     
     
         50 . The method of  claim 49 , wherein forming the at least one hole in the supportive structure comprises drilling the at least one hole. 
     
     
         51 . The method of  claim 48 , further comprising at least partially curing the cement so that at least one attachment structure located on a distal portion of the peg mechanically interlocks with a cement mantle in the supportive substrate.