Total knee replacements for hinged knee implants include a tibial member, a femoral member, a hinge assembly having a laterally extending axle configured to hingedly attach the femoral member to the tibial member, and a lock mechanism in communication with the hinge assembly. The lock mechanism is configured to (i) lock the femoral member in alignment with the tibial member for a full extension or other defined stabile walking configuration to thereby allow an arthrodesis or stiff knee gait and (ii) unlock to allow the femoral and tibial members to pivot relative to each other for flexion or bending when not ambulating.

The implantable prosthesis for replacing a human knee joint comprises a femoral prosthetic element (12) and a tibial prosthetic element (14) which are articulated with one another by means of a joint device (30) for the purpose of executing a knee bend. The tibial prosthetic element (14) has a through-opening (40) for the passage of a tool (84), a rod-like shaft anchoring part (32) or an intramedullary lengthening nail (80). In order to reduce the extent of a surgical intervention and thus the risk of infection also for the lengthening of the tibia, the joint device (30) is designed such that it forms a guide channel (42) for the passage of the tool (84), the rod-like shaft anchoring part (32) or the intramedullary lengthening nail (80) from the outside, which guide channel is in alignment with the through-opening (40) and is in connection therewith when the tibial prosthetic element (14) and the femoral prosthetic element (12) are arranged at a predetermined angle relative to one another in a functional position corresponding to a knee bend.

A total knee prosthesis including a tibial component having a baseplate portion and a protruding portion extending from the baseplate portion is disclosed. An axle is connectable to the tibial component directly or indirectly. A femoral component has an articular surface and an opening for receipt of the axle. The opening defines a pivot center about which the femoral prosthesis rotates. The articular surface has a posterior portion having a first flexion radius defining a first flexion center. The first flexion center is offset from the pivot center a distance substantially equal to a product of a constant and the first flexion radius.

The invention relates to a knee joint endoprosthesis has a tibia part, a femur part, a meniscus part arranged on the tibia part in mutually non-rotatable manner and a connecting device for connecting the tibia part to the femur part in articulated manner. Said femur part comprises at least one femur condyle having a femur condyle surface. Said meniscus part comprises at least one upper surface which faces the femur part and has at least one meniscus joint surface which touches the femur condyle surface of the at least one femur condyle. Said femur part and the tibia part are mounted such as to be rotatable relative to each other about a rotational axis.

A system including a prosthesis assembly for a constrained knee including a tibial baseplate, a mobile bearing, and a fixed bearing. The tibial baseplate can include a distal surface and a proximal surface that can be configured to receive a hinge post. The mobile bearing can be configured to couple with the tibial baseplate and to rotate about at least a first axis approximated by a centerline of the hinge post. The rotation about at least the first axis can be limited by at least the first engagement feature. The fixed bearing can be configured to be coupled to the tibial baseplate. The fixed bearing can be restrained from rotating about the first axis by at least the first engagement feature of the tibial baseplate. The tibial baseplate can be configured to be assembled with either the mobile bearing or the fixed bearing.

A total knee prosthesis system that includes a guide having first and second wedges each having a thickness configured to be located between the tibial and femoral component. When the first and second wedges are located between the tibial and femoral component, the first and second wedges align the first axle opening of the tibial component with the second axle opening of the femoral component for receipt of an axle. The guide includes a guide recess extending between the first and second wedges and a post extending into the guide recess. The guide also includes a bridge connected to and extending between the first and second wedges such that the bridge at least partially defines the guide recess.

A hinged articulating spacer system for revision knee arthroplasty includes a femur rod for a femur, and a tibia rod for a tibia. The tibia rod is hingedly couplable to the femur rod to form a hinged rod assembly. A pre-formed femoral spacer component includes bone cement impregnated with an antibiotic. The pre-formed femoral spacer defines an opening that receives the hinged rod assembly. A pre-formed tibial spacer component includes bone cement impregnated with an antibiotic. The pre-formed tibial spacer defines an opening that receives the hinged rod assembly.