Cannulated Hemi-Implant and Methods of Use Thereof

Abstract

The present invention provides a cannulated hemi-implant with a base and a threaded stem for fixing the stem of the implant within a medullary canal of a phalanx or other bone in the foot. The implant includes a tri-part head capable of both cutting bone and self-threading, with bone forming the medullary canal of a phalanx of a human foot. The present invention also provides a hand tool which engages and rotates the implant within the medullary canal of the phalanx. The present invention further provides a method of surgically implanting the implant in the medullary canal of the phalanx or other bone.

1 - 32 . (canceled) 
     
     
         33 . A one-piece implant comprising an elliptically-shaped base having a bottom surface, a side surface, a rounded rim and an ellipsoidal articular surface, said base having a threaded stem with a tri-part head protruding perpendicularly away from said bottom surface of said base, and wherein a central cannulation is provided through said elliptically-shaped base and said stem. 
     
     
         34 . The one-piece implant of claim  1 , wherein threads are provided on the exterior surface of said stem. 
     
     
         35 . The one-piece implant of claim  1 , wherein said elliptically-shaped base comprises a major diameter and a minor diameter. 
     
     
         36 . The one-piece implant of claim  1 , wherein said ellipsoidal articular surface provides a concavity capable of articulation with a portion of a joint. 
     
     
         37 . The one-piece implant of claim  1 , wherein said implant has a major diameter of between about 40.0 mm and 10.0 mm, a minor diameter of between about 35.0 mm and 8.0 mm, said stem has a length of between about 15.0 mm and 1.0 mm and a diameter of between about 10.0 mm and 4.0 mm, said base has a thickness of between about 4.0 mm and 0.5 mm, said threads have a pitch of between about 2.0 mm and 1.0 mm, and said cannulation has a diameter of between about 4.0 mm and 0.5 mm. 
     
     
         38 . The one-piece implant of claim  1 , wherein said implant has a major diameter of 15.0 mm, a minor diameter of 13.0 mm, said stem has a length of 4.0 mm and a diameter of 7.5 mm, said base has a thickness of 1.8 mm, and said threads have a pitch of 1.65 mm. 
     
     
         39 . The one-piece implant of claim  1 , wherein said implant has a major diameter of 17.0 mm, a minor diameter of 15.0 mm, said stem has a length of 5.0 mm and a diameter of 7.5 mm, said base has a thickness of 2.0 mm, said threads have a pitch of 1.65 mm, and said cannulation has a diameter of 1.6 mm. 
     
     
         40 . The one-piece implant of claim  1 , wherein said implant has a major diameter of 19.0 mm, a minor diameter of 17.0 mm, said stem has a length of 6.0 mm and a diameter of 7.5 mm, said base has a thickness of 2.1 mm, said threads have a pitch of 1.76 mm, and said cannulation has a diameter of 1.6 mm. 
     
     
         41 . The one-piece implant of claim  1 , wherein said implant has a major diameter of 22.0 mm, a minor diameter of 19.0 mm, said stem has a length of 7.0 mm and a diameter of 6.5 mm, said base has a thickness of 2.2 mm, said threads have a pitch of 1.76 mm, and said cannulation has a diameter of 1.6 mm. 
     
     
         42 . The one-piece implant of claim  1 , wherein said implant has a major diameter of 24.0 mm, a minor diameter of 21.0 mm, said stem has a length of 8.0 mm and a diameter of 6.5 mm, said base has a thickness of 2.3 mm, said threads have a pitch of 1.76 mm, and said cannulation has a diameter of 1.6 mm. 
     
     
         43 . A cannulated hemi-implant system comprising a one-piece implant having an elliptically-shaped base with an ellipsoidal articular surface and a threaded stem having a tri-part head, a hand tool having an engagement surface with an element selected from the group consisting of metal wedge holders, a sleeve and prongs, a trial sizer, a blade guide, and a guide wire.