Abstract: A femoral extension prosthetic component for use in a unicondylar meniscal bearing unicompartmental knee replacement is described. The femoral component comprises a securing element and a bearing surface, the securing element adapted to abut and be connected to a distal end of a femur bone, and the Dearing surface adapted to abut a meniscal bearing. The femoral component includes an entrapment portion adapted to extend beyond the meniscal bearing. Tibial components and meniscal bearings are also described, as well as methods of using such components.

Abstract: A rotary mill is disclosed comprising a body portion (4) having a milling surface (10) and a central bore (30) extending along an axis of rotation (18) of the body portion (4), and a guide portion (6) having a guide body (22) and a guide peg (24) extending from the guide body (22), the guide peg (24) operable to be received in the central bore (20) of the body portion (4), the guide body (22) having at least one alignment feature (28, 30) which is the same as that of a prosthesis component.

Abstract: Systems, devices, and methods are provided for measuring forces in the space of a knee during surgery. Such forces can be caused by tension in the ligaments of the knee. A femoral member is engaged with a distal femur. While the knee is flexed, partially extended, or fully extended, a force sensor and a gauge shim can be placed in the gap between the femoral member and the tibial plateau to measure the forces therebetween. The force sensor provides an accurate and quantifiable measurement of force, making knee replacement surgery and ligament tension balancing more accurate, standardized and repeatable. The force sensor comprises an elongate housing which comprises a thin force sensing distal portion and a proximal handle portion.

Abstract: A bearing for a total or partial joint replacement prosthesis: the bearing having a body and a reinforcing element which strengthens the bearing and which forms an attachment member, and/or the bearing being formed at least partially from polymeric or composite material the bearing comprising a lower modulus portion and a higher modulus portion, one portion of the bearing being at least partially encased by the other portion of the bearing. Also provided is a method for of forming the bearing, and a total or partial joint replacement prosthesis comprising the hearing.

Abstract: An artificial ligament is provided having an elongate body and two ends, with a loop being provided at least one of the ends and a loop liner being provided within the loop. A kit of artificial ligaments is also provided with each ligament in the kit having a different fixed length. Also provided are methods for determining a length of artificial ligament to be used within a prosthetic knee joint, selecting a ligament from a range or kit of ligaments, and implanting a prosthetic knee joint assembly comprising an artificial ligament.

Abstract: A method of implanting a lateral unicondylar knee prosthesis in a lateral articulating portion of a femur having a lateral condyle for engagement with a tibia, the method including the steps of: bending a patients knee such that the knee is not in full extension; making an incision through the skin, muscle, and other soft tissue until the damaged bone surfaces are exposed; resecting an end portion of the lateral tibia; resecting an end portion of the lateral femoral condyle; attaching a tibial prosthetic component to the resected end portion of the tibia; attaching a lateral femoral condyle prosthetic component to the resected end portion of the lateral femoral condyle; determining the thickness of a mobile bearing member with the knee in full extension; and inserting the mobile bearing member between the tibial prosthetic component and the femoral prosthetic component.

Abstract: A ligament assembly (2) comprising a resilient element (20) connected to a bone anchor (4) and a ligament (18), the resilient element (20) acting m a cantilever and resisting toads transmitted between the bone anchor (4) and the ligament (18) by virtue of the resistance to bending of the resilient element. The ligament (18) may comprise an artificial ligament (18) which is adapted to replace a human or animal ligament. The resilient element (20) may comprise a spiral spring and may act as a biasing element/shock absorber operatively coupled to the artificial ligament (18) to control the effective stiffness of the artificial ligament (18). Consequently, the resilient element (20) enables an effective stiffness of the artificial ligament (18) to be achieved that more closely approximates the stiffness of a natural ligament.

Abstract: A bearing component 2 for a joint replacement prosthesis comprises a first bearing element 4; a second bearing element 6, and a linking element 8, operatively connecting the first and second bearing elements 4, 6 and permitting relative motion there between. The flexible linking element 8 prevents dislocation of mobile bearings in a total knee replacement prosthesis. The invention also relates to a bridging element which retains the linking element 8 with some play, which acts as a ligament support 2051, and which causes a deflection of the line of action of a ligament 1018. A joint replacement prosthesis is also disclosed comprising a biasing element 1140 or a tensioning element 1220 operatively coupled to the artificial ligament 1018. The biasing element 1140 or tensioning element 1220 may be housed in the stem of a tibia tray 1006.

Abstract: A ligament assembly (2) comprising a resilient element (20) connected to a bone anchor (4) and a ligament (18), the resilient element (20) acting m a cantilever and resisting toads transmitted between the bone anchor (4) and the ligament (18) by virtue of the resistance to bending of the resilient element. The ligament (18) may comprise an artificial ligament (18) which is adapted to replace a human or animal ligament. The resilient element (20) may comprise a spiral spring and may act as a biasing element/shock absorber operatively coupled to the artificial ligament (18) to control the effective stiffness of the artificial ligament (18). Consequently, the resilient element (20) enables an effective stiffness of the artificial ligament (18) to be achieved that more closely approximates the stiffness of a natural ligament.

Abstract: A ligament balancer for a knee is disclosed that includes a first guide portion having a first guide hole extending there through, and a second guide portion having a second guide hole extending there through, the first and second guide portions being moveable with respect to each other along a movement axis, the balancer being adapted such that, in use, the movement axis is substantially parallel to the anterior/posterior axis of a distal femoral surface. Also disclosed is a kit of parts that includes the ligament balancer and a drill guide for a knee, the drill guide includes first and second connected arms, each arm comprising at least two guide openings extending there through, the guide openings being spaced longitudinally along each arm, longitudinal axes of the first and second arms intersecting at a predetermined angle. Also disclosed is a method of attaching a cutting block to a distal femoral surface as part of a knee replacement procedure.

Abstract: A rotary mill is disclosed comprising a body portion (4) having a milling surface (10) and a central bore (20) extending along an axis of rotation (18) of the body portion (4); and a guide portion (6) having a guide body (22) and a guide peg (24) extending from the guide body (22), the guide peg (24) operable to be received in the central bore (20) of the body portion (4), the guide body (22) having at least one alignment feature (28, 30) which is the same as that of a prosthesis component.

Abstract: A femoral component (101) for a knee prosthesis, the femoral component (101) comprising: a body portion (103) having: a lateral portion (109) and a medial portion (111) when in an implanted configuration, wherein a parasagittal plane is located at the intersection between the lateral portion (109) and the medial portion (111); and a patella track (105) extending anterior-posteriorly around the body portion (103), wherein the patella track (105) comprises a first patella track portion (105a) that is directed laterally away from the parasagittal plane as it extends towards a posterior end of the patella track (105).

Abstract: Systems, devices, and methods are provided for measuring forces in the space of a knee during surgery. Such forces can be caused by tension in the ligaments of the knee. A femoral member is engaged with a distal femur. While the knee is flexed, partially extended, or fully extended, a force sensor and a gauge shim can be placed in the gap between the femoral member and the tibial plateau to measure the forces therebetween. The force sensor provides an accurate and quantifiable measurement of force, making knee replacement surgery and ligament tension balancing more accurate, standardized and repeatable. The force sensor comprises an elongate housing which comprises a thin force sensing distal portion and a proximal handle portion.

Abstract: A rotary mill is disclosed comprising a body portion (4) having a milling surface (10) and a central bore (20) extending along an axis of rotation (18) of the body portion (4); and a guide portion (6) having a guide body (22) and a guide peg (24) extending from the guide body (22), the guide peg (24) operable to be received in the central bore (20) of the body portion (4), the guide body (22) having at least one alignment feature (28, 30) which is the same as that of a prosthesis component.

Abstract: A bearing component 2 for a joint replacement prosthesis comprises a first bearing element 4; a second bearing element 6, and a linking element 8, operatively connecting the first and second bearing elements 4, 6 and permitting relative motion there between. The flexible linking element 8 prevents dislocation of mobile bearings in a total knee replacement prosthesis. The invention also relates to a bridging element which retains the linking element 8 with some play, which acts as a ligament support 2051, and which causes a deflection of the line of action of a ligament 1018. A joint replacement prosthesis is also disclosed comprising a biasing element 1140 or a tensioning element 1220 operatively coupled to the artificial ligament 1018. The biasing element 1140 or tensioning element 1220 may be housed in the stem of a tibia tray 1006.

Abstract: A prosthesis (100, 200) comprising a bone attachment component (106) having one or more fixation structures (124, 224), wherein the prosthesis is configured to be selectively convertible between a mobile bearing prosthesis, in which a barrier (120) is secured to the bone attachment component (106) using the fixation structures, and a constrained bearing prosthesis, in which a bearing component (204) is secured to the bone attachment component (106) using the fixation structures (124, 224).

Abstract: A guide tool (100) for guiding resection of a bone piece, comprising a body (102), a burr guide opening (130) extending through the body (102) and defining a burr resection surface, and a saw guide opening (120) extending through the body (102) and defining a saw resection surface, the burr guide opening (130) and the saw guide opening (120) being aligned such that the burr resection surface and the saw resection surface intersect, defining a bone piece resection surface.

Abstract: A bearing component 2 for a joint replacement prosthesis comprises a first bearing element 4; a second bearing element 6, and a linking element 8, operatively connecting the first and second bearing elements 4, 6 and permitting relative motion there between. The flexible linking element 8 prevents dislocation of mobile bearings in a total knee replacement prosthesis. The invention also relates to a bridging element which retains the linking element 8 with some play, which acts as a ligament support 2051, and which causes a deflection of the line of action of a ligament 1018. A joint replacement prosthesis is also disclosed comprising a biasing element 1140 or a tensioning element 1220 operatively coupled to the artificial ligament 1018. The biasing element 1140 or tensioning element 1220 may be housed in the stem of a tibia tray 1006.

Abstract: The invention concerns a tibial prosthetic component comprising a plate (100) for forming a tibial plateau of a tibia (16), wherein a peripheral region of the plate (100) has a thickness of less than 3 mm. The invention also concerns a tibial prosthetic component having a keel of depth less than 9 mm. The invention also concerns a method of selecting a tibial prosthetic component comprising receiving measurements of at least one physical attribute of an individual into whom the tibial prosthetic component is to be implanted, selecting a thickness of a plate (100) and depth of keel of the tibial prosthetic component based on the measurements and providing a tibial prosthetic component comprising a plate (100) having the selected thickness and a keel having the selected depth.

Abstract: A femoral extension prosthetic component for use in a unicondylar meniscal bearing unicompartmental knee replacement is described. The femoral component comprises a securing element and a bearing surface, the securing element adapted to abut and be connected to a distal end of a femur bone, and the bearing surface adapted to abut a meniscal bearing. The femoral component includes an entrapment portion adapted to extend beyond the meniscal bearing. Tibial components and meniscal bearings are also described, as well as methods of using such components.