Patent ID: 8092546

Claim:
A prosthesis for use in knee arthroplasty including a tibial component and a femoral component, the femoral component having at least one condyle, the tibial component comprising: (a) a tibial base having: (i) an inferior surface for engagement with a prepared surface at the proximal end of a tibia, (ii) a superior surface opposite said inferior surface, (iii) a passageway extending through said tibial base, said passageway having an open proximal end adjacent said superior surface and an open distal end adjacent said inferior surface, said passageway having a wall surface portion defining a Morse taper portion, said Morse taper portion tapering inwardly from said superior surface toward said inferior surface, and (iv) an enlarged threaded aperture adjacent said superior surface and defining a shoulder extending outwardly from said Morse taper portion; (b) a tibial stem received within said passageway of said tibial base with at least a portion of said tibial stem extending distally from said open distal end of said passageway of said tibial base such that said tibial stem extends distally from said inferior surface of said tibial base, said tibial stem having: (i) a portion defining a Morse taper sized to engage said Morse taper portion of said passageway of said tibial base, and (ii) a threaded flange portion proximal of said portion of said tibial stem defining said Morse taper, said threaded flange portion threadably engageable with said enlarged threaded aperture of said tibial base, such that when said threaded flange portion is threadably engaged with said threaded aperture and said portion of said tibial stem defining said Morse taper is snugly engaged to said Morse taper portion of said tibial base, a gap remains between a distal side of said flange portion and a proximal surface of said shoulder, whereby threaded engagement of said threaded flange portion with said threaded aperture ensures firm engagement between said Morse taper portion of said tibial base and said Morse taper of said tibial stem; and (c) an insert positioned on said superior surface of said tibial base, said insert contoured to be engaged by the condyle of the femoral component.