Tibial Resurfacing System and Method
An implant resection system for preparing an implant site to replace a defect in an articular surface of a first bone includes a guide configured to be coupled generally perpendicular to the first bone proximate to the defect. The guide includes a body portion defining a plurality of excision passageways. The excision passageways each define a generally cylindrical core pathway configured to extend generally perpendicular to the first bone which partially overlaps with an adjacent generally cylindrical core pathway. A projection associated with each of the plurality of the generally cylindrical core pathways defines a truncated cylindrical excision site extending through a portion of the articular surface. Each truncated cylindrical excision site partially overlaps with at least one adjacent truncated cylindrical excision site.
1 . An implant resection system for preparing an implant site to replace a defect in an articular surface of a first bone, said implant resection system comprising:
a guide configured to be coupled generally perpendicular to said first bone proximate to said defect, said guide comprising a body portion defining a plurality of excision passageways, said excision passageways each defining a generally cylindrical core pathway configured to extend generally perpendicular to said first bone which partially overlaps with an adjacent generally cylindrical core pathway, wherein a projection associated with each of said plurality of said generally cylindrical core pathways defines a truncated cylindrical excision site extending through a portion of said articular surface, and wherein each truncated cylindrical excision site partially overlaps with at least one adjacent truncated cylindrical excision site.
2 . The implant resection system of claim 1 , further comprising:
an arm extending outwardly from a distal face of said body portion of said guide; and
a spoon disposed about a distal end of said arm, said spoon configured to be disposed between said articular surface of said first bone and an articular surface of a cooperating bone.
3 . The implant resection system of claim 2 , wherein said spoon further comprises a generally convex base portion configured to abut against said articular surface of said first bone.
4 . The implant resection system of claim 3 , wherein said spoon further comprises a generally concaved upper portion configured to abut against said articular surface of said cooperating bone.
5 . The implant resection system of claim 2 , further comprising:
a locking passageway extending through a portion of said arm; and
at least one pin configured to be advanced through said locking passageway and into said first bone and to secure said spoon relative to said first bone.
6 . The implant resection system of claim 5 , wherein said locking passageway is configured to align said at least one pin such that said at least one pin extends into said first bone proximate to the meniscus.
7 . The implant resection system of claim 1 , further comprising:
a locking passageway extending through a portion of said body portion; and
at least one pin configured to be advanced through said locking passageway and into said first bone and to secure said body portion relative to said first bone.
8 . The implant resection system of claim 1 , further comprising:
a dowel having a longitudinal passageway, said dowel configured to be advanced through a first of said plurality of excision passageways and to abut against said first bone; and
a pin configured to be advanced through said longitudinal passageway of said dowel and into said first bone;
wherein said dowel and said pin are configured to secure said body portion relative to said first bone.
9 . The implant resection system of claim 8 , further comprising a locking feature to secure said dowel within said first excision passageway.
10 . The implant resection system of claim 1 , further comprising a core drill configured to advanced through a first one of said plurality of excision passageways along a first of said generally cylindrical core pathways to remove a portion of said bone and said articular surface to define a first of said plurality of partially overlapping truncated cylindrical excision sites.
11 . The implant resection system of claim 10 , further comprising:
a pin configured to be advanced through said first excision passageway and into said first bone;
wherein said core drill further comprises a centering bushing disposed within a core cavity of said core drill, said centering bushing configured to be advanced over said pin and to center said core drill along said generally cylindrical core pathway associated with said first excision passageway.
12 . The implant resection system of claim 1 , wherein said plurality of excision passageways includes a first, a second, and a third excision passageway, said third excision passageway partially overlapping said first and said second excision passageways;
wherein said guide further comprises a first and a second protrusion configured to extend from said body portion and to be received in a truncated cylindrical excision site associated with said first and said second excision passageway, respectively.
13 . The implant resection system of claim 12 , wherein said first and said second protrusions further comprise alignment passageways, each alignment passageway configured to be advanced over an associated pin to secure said guide to said first bone while a core drill is advanced through said third excision passageway to form an excision site associated with said third excision passageway.
14 . The implant resection system of claim 1 , further comprising an implant comprising:
a load bearing surface having a contour substantially corresponding to a contour of the articular surface corresponding to said implant site; and
a bone facing surface having a contour substantially corresponding to the contour of said plurality of truncated cylindrical excision sites formed in said first bone.
15 . The implant resection system of claim 14 , wherein said bone facing surface further comprises a plurality of relief cavities configured secure said implant to said bone.
16 . The implant resection system of claim 14 , further comprising a keel extend generally away from said bone facing surface, said keel configured to engage a corresponding notch formed in one of said plurality of truncated cylindrical excision sites.
17 . The implant resection system of claim 14 , wherein said first bone is a tibia, and wherein said implant includes a “D” shaped cross-section.
18 . The implant resection system of claim 14 , wherein said implant comprises an upper portion configured to be secured to a lower portion, said upper portion comprising said load bearing surface and said lower portion comprising said bone facing surface.
19 . A method for preparing an implant site to replace a defect in an articular surface, said method comprising:
securing a guide to bone proximate said defect, said guide comprising a body portion defining a plurality of excision passageways, each excision passageway defining a generally cylindrical core pathway which partially overlap with an adjacent generally cylindrical core pathway; and
advancing at least one drill through said plurality of excision passageways along said generally cylindrical core pathways to form a plurality of partially overlapping truncated cylindrical excision sites extending through said articular surface.