Modular knee prosthesis system

[0002] The disclosures herein related generally to knee prostheses and more particularly to a modular knee prosthesis system.

[0003] Knee replacement systems are provided for partial and total knee replacement. Such systems are used for distal femoral repair, proximal tibia repair, and combined distal femoral/proximal tibia repair. Because of variations in bone loss, there are variations in components required in knee replacement systems. While some of the components vary, depending on surgical requirements, there are some components which are used in all or substantially all of the replacement systems. As a result, some component modularity has been introduced.

[0004] Total knee replacement may be required for a revision hinged orthopedic application, or a hinged orthopedic application, i.e. minor bone loss; a tibial orthopedic oncology-trauma application, i.e. major tibial bone loss; a femoral orthopedic oncology-trauma application, i.e. major femoral bone loss; and a distal femur-proximal tibia orthopedic oncology-trauma application, i.e. major tibial and femoral bone loss. In these applications, component requirements vary greatly. In order to meet the requirements, a substantial inventory of components is required, and at a considerable cost. Also, several instruments and implant trials are required because of the various techniques used for each orthopedic procedure.

[0005] Therefore, what is needed is a system and apparatus that provides for modularity and flexibility between orthopedic, orthopedic oncology and orthopedic trauma surgical applications.

[0006] One embodiment, accordingly, provides a system and apparatus that uses the same modular components for hinged orthopedic applications, revision hinged orthopedic applications, orthopedic oncology applications and orthopedic trauma applications. To this end, a modular knee system includes a hinged femoral component and a distal femoral component. A plurality of first stem components are selectively compatible with the hinged femoral component. A plurality of first adaptors are selectively compatible with the first stem components and the distal femoral component. A hinge component is connected to a tibial insert. The hinge component and the tibial insert are selectively compatible with the hinged femoral component and the distal femoral component. A hinged tibial component and a proximal tibial component are selectively compatible with the tibial insert. A plurality of second stem components are selectively compatible with the hinged tibial component. A plurality of second adaptors are selectively compatible with the second stem components and the proximal tibial component.

[0007] A principal advantage of this embodiment is that modular components are used for several surgical applications including hinged orthopedic applications, revision hinged orthopedic applications, orthopedic oncology applications and orthopedic trauma applications, thus reducing component inventory and costs.

[0008] FIG. 1 is a diagrammatic view illustrating an embodiment of a modular knee prosthesis system.

[0009] FIG. 2 is a cross-sectional view, taken along the line 2—2 of FIG. 1, illustrating an embodiment of a stem.

[0010] FIG. 3 is a cross-sectional view, taken along the line 3—3 of FIG. 1, illustrating another embodiment of a stem.

[0011] FIG. 4 is a diagrammatic view illustrating an embodiment of a hinged modular knee application.

[0012] FIG. 5 is a diagrammatic view illustrating another embodiment of a hinged modular knee application.

[0013] FIG. 6 is a diagrammatic view illustrating a further embodiment of a hinged modular knee application.

[0014] FIG. 7 is a diagrammatic view illustrating another embodiment of a hinged modular knee application.

[0015] A modular knee system is generally designated 10 in FIG. 1. Knee system 10 includes a plurality of first stem components 12a, 12b, 12c. Stem components 12a-cmay be of variable lengths, diameters and shapes as required for anatomical suitability with the intramedullary canal of a femur (not shown). The stem components 12a-cmay also include a full or partial porous coating. An outer surface 14, FIG. 2, of stem component 12amay be substantially circular and include a plurality of grooves 16 extending inwardly therefrom. Alternately, the outer surface 14 of stem component 12c, FIG. 3, may be substantially circular and include a plurality of flutes 18 extending outwardly therefrom. A rounded first end 20 of each stem 12a-cinserts into the femoral intramedullary canal. A tapered second end 22 of each stem 12a-cinserts into a component discussed below.

[0016] Depending upon surgical requirements, either a hinged femoral component 24 or a distal femoral component 26 is selected. Any one of the first stem components 12a-cmay be used with the hinged femoral component 24. The tapered second end 22 of the stem components 12a-ccan seat in a mating tapered receptacle 23 in the component 24. A spacer or spacers 28 may be seated on the hinged femoral component 24 to provide an anatomical adjustment, if required. A plurality of first adaptors 30aand 30b, provide a selective interconnection between the tapered end 22 of the selected one of the stems 12a-cand the distal femoral component 26. The adaptor 30ais provided with an extension portion 31. The extension portion 31 may be provided with a porous coating 33 to promote bone in-growth. In addition, a segment 30cmay be used in combination with the adaptors 30aand 30b. The segment 30calso has an extension portion 31 which may include the porous coating 33. Adaptors 30aand 30b, and the segment 30c, have a tapered end 35 which seats in a mating tapered receptacle 37 in the component 26.

[0017] A hinge component 36 is provided with a tapered portion 38 for insertion into a mating tapered seat 40 provided in a tibial insert 42. The hinge component 36 is connected to either the hinged femoral component 24 or the distal femoral component 26 by a known pin and bushing arrangement (not shown). The tibial insert 42 has a tapered end 44 for seating in a mating tapered seat 46, 47 in either a hinged tibial component 48 or a proximal tibial component 50, respectively. Depending on surgical requirements, either the hinged tibial component 48 or the proximal tibial component 50 is selected.

[0018] Knee system 10 includes a plurality of second stem components 52a, 52b, 52c, 52d. Stem components 52a-dmay be of variable lengths, diameters and shapes as required for anatomical suitability with the intramedullary canal of a tibia (not shown). The stem components 52a-dmay also include a full or partial porous coating. An outer surface of the stems 52a-dmay include grooves or flutes as discussed above. A rounded first end 54 of each stem inserts into the tibial intramedullary canal (not shown). A tapered second end 56 of each stem 52a-dinserts into the hinged tibial component 48.

[0019] Any one of the second stem components 52a-dmay be used with the hinged tibial component 48, or alternately, a plug 59 may be used with hinged tibial component 48. The tapered second end 56 of the stem components 52a-d, or plug 59, can seat in a mating tapered receptacle 53 in the component 48. A spacer or spacers 58 may be seated on the hinged tibial component 48 to provide an anatomical adjustment, if required. A plurality of second adaptors 60aand 60b, provide a selective interconnection between the tapered end 56 of the selected one of the stems 52a-dand the proximal tibial component 50. The adaptor 60ais provided with an extension portion 61. The extension portion 61 may be provided with a porous coating 63 to promote bone in-growth. In addition a segment 60cmay be used in combination with the adaptors 60aand 60b. The segment 60calso has an extension portion 61 which may include the porous coating 63. Adaptors 60aand 60b, and the segment 60chave a tapered end 55 which seats in a mating tapered receptacle 57 of the component 50.

[0020] In operation, the hinged femoral component 24 and the distal femoral component 26 are provided. The plurality of first stem components 12a-care provided and are compatible with the hinged femoral component 24. One of the first stem components 12a-cis selected. The plurality of first adaptors 30aand 30bare provided and are compatible with the first stem components 12a-cand the distal femoral component 26. One of the femoral components 24, 26 is selected. If the hinged femoral component 24 is selected, it is connected to the selected first stem component 12a-c. One of the first adaptors 30a, 30bis selected in the instance where the distal femoral component 26 is selected as an alternate to the hinged femoral component 24. The selected one of the first adaptors 30a, 30bis connected between the distal femoral component 26 and the selected first stem component 12a-c. The selected one of the femoral components 24, 26 is connected to the hinge component 36 which is attached to the tibial insert 42. The hinged tibial component 48 and the proximal tibial component 50 are provided. The second stem components 52a-dare compatible with the hinged tibial component 48. One of the second stem components 52a-dis selected for connection to the hinged tibial component 48, or alternately, the plug 59 is selected to be attached to the hinged tibial component 48. In the instance where the proximal tibial component 50 is selected, the second adaptors 60aand 60bare provided, and, the selected one of the second adaptors 60a, 60b, is positioned between the selected one of the second stem component 52a-dand the proximal tibial component 50.

[0021] As a result, one application for the modular system 10, is illustrated in FIG. 4. A selected one of the first stems 12a-cmay be connected to the hinged femoral component 24. A selected one of the second stems 52a-dmay be connected to the hinged tibial component 48, or alternately, the plug 59 may be connected to the hinged tibial component 48. The hinged femoral component 24 may be interconnected with the hinged tibial component 48 by means by the hinge component 36 and the tibial insert 42. If anatomical adjustment is required, the spacer 28 may be used with the hinged femoral component 24, and the spacer 58 may be used with the hinged tibial component 48.

[0022] Another application for the modular system 10 is illustrated in FIG. 5. A selected one of the first stems 12a-cmay be connected to the hinged femoral component 24. A selected one of the second stems 52a-dand a selected one of the second adaptors 60a, 60b, may be connected to the proximal tibial component 50. The hinged femoral component 24 may be interconnected with the proximal tibial component 50 by means of the hinge component 36 and the tibial insert 42. If anatomical adjustment is required, the spacer 28 may be used with the hinged femoral component 24.

[0023] A further application for the modular system 10 is illustrated in FIG. 6. A selected one of the first stems 12a-cand a selected one of the first adaptors 30a, 30b, may be connected to the distal femoral component 26. A selected one of the second stems 52a-dmay be connected to the hinged tibial component 48, or alternately, the plug 59 may be connected to the hinged tibial component 48. The distal femoral component 26 may be interconnected with the hinged tibial component 48 by means of the hinge component 36 and the tibial insert 42. If anatomical adjustment is required, the spacer 58 may be used with the hinged tibial component 48.

[0024] Another application for the modular system 10 is illustrated in FIG. 7. A selected one of the first stems 12a-cand a selected one of the first adaptors 30a, 30b, may be connected to the distal femoral component 26. A selected one of the second stems 52a-dand a selected one of the second adaptors 60a, 60b, may be connected to the proximal tibial component 50. The distal femoral component 26 may be interconnected with the proximal tibial component 50 by means of the hinge component 36 and the tibial insert 42.

[0025] As it can be seen, the principal advantages of these embodiments are that modular components are used for several surgical applications including hinged orthopedic, revision hinged orthopedic, orthopedic oncology and orthopedic trauma. By using the same components in several surgical applications the cost of offering the system is reduced. The surgical technique is simplified because there are fewer instruments required, e.g. implant trials and surgical instruments, because the same technique and instruments can be used for several orthopedic applications. The system is also provided to maintain the anatomically correct joint line for femur, tibia and patella.

[0026] As a result, the same hinge component and tibial insert combination is used in various applications. Also, the same hinged tibial component is used for stemmed and stemless applications. A variety of stems can be used with the hinged femoral and distal femoral components, with the hinged tibial and proximal tibial components, and in other modular knee prosthesis applications and systems. In addition, a variety of stems can be used with a variety of adaptors which may include a porous coating.

[0027] Although illustrative embodiments have been shown and described, a wide range of modification, change and substitution is contemplated in the foregoing disclosure and in some instances, some features of the embodiments may be employed without a corresponding use of other features. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the embodiments disclosed herein.