Abstract: Methods and apparatus for planning and/or carrying out a total knee replacement surgical procedure on a knee of a leg of a patient are described. Anatomical data for the leg of the patient is obtained, which allows the femoral mechanical axis, the tibial mechanical axis, and the joint line of the knee to be determined. A planned proximal tibial cut angle and a planned distal femoral cut angle are determined. A total knee replacement procedure is carried out on the knee of the patient such that a distal femoral cut is made using the planned distal femoral cut angle and a proximal tibial cut is made using the planned proximal tibial cut angle.

Abstract: An assembly for use in knee surgery includes a patella sensor component having a backing plate which can be fitted to the patella and which has at least one sensor which can generate a signal corresponding to the compressive load applied to the backing plate, and at least first and second shims which provide a patella bearing surface for articulation against a surface on the patient's femur, and which can be positioned individually or in one or more combinations between the backing plate and the patient's patella to define first and second positions of the bearing surface relative to the patella. The assembly includes a clamp for a patella having opposing jaws which can be moved towards one another to clamp the patella between them, the clamp providing a reference surface for engaging the posterior surface of the patella and a support surface for supporting the cutting head of a cutting instrument, thereby locating the cutting instrument relative to the clamp.

Abstract: A cutting assembly for resecting a patient's patella during knee surgery comprises a cutting instrument having a cutting head for cutting the patella on a selected resection plane, and a patella clamp having opposing jaws which can be moved towards one another to clamp the patella between them. The clamp provides a reference surface for engaging the posterior surface of the patella, and a support surface for supporting the cutting head of the cutting instrument, thereby locating the cutting instrument relative to the clamp. The assembly includes a plurality of connector inserts which can be mounted individually or in one or more combinations on or relative to the clamp, providing a physical connection between the reference and support surfaces which defines the inclination of the support surface relative to the reference surface so that the inclination of the support surface relative to the reference surface can be varied by changing one or more of the connector inserts.

Abstract: A kit for use in knee replacement surgery includes a trial patella component and a patella implant component. The trial patella component includes a backing plate having a backing surface for positioning against a patient's patella, and at least one sensor which can generate a signal corresponding to the compressive load applied to the trial patella component, and a first bearing plate which can be fitted to the backing plate and which, when fitted to the backing plate, provides a bearing surface for articulation against a bearing surface on the patient's femur. The patella implant component has a backing surface for fixation to a patient's patella instead of the backing surface of the trial patella component, and a bearing surface for articulation against a femoral bearing surface.

Abstract: Methods and apparatus for planning and/or carrying out a total knee replacement surgical procedure on a knee of a leg of a patient are described. Anatomical data for the leg of the patient is obtained, which allows the femoral mechanical axis, the tibial mechanical axis, and the joint line of the knee to be determined. A planned proximal tibial cut angle and a planned distal femoral cut angle are determined. A total knee replacement procedure is carried out on the knee of the patient such that a distal femoral cut is made using the planned distal femoral cut angle and a proximal tibial cut is made using the planned proximal tibial cut angle.

Abstract: Methods and apparatus for planning and/or carrying out a total knee replacement surgical procedure on a knee of a leg of a patient are described. Anatomical data for the leg of the patient is obtained, which allows the femoral mechanical axis, the tibial mechanical axis and the joint line of the knee to be determined. A planned proximal tibial cut angle and a planned distal femoral cut angle are determined. A total knee replacement procedure is carried out on the knee of the patient, wherein a distal femoral cut is made using the planned distal femoral cut angle and a proximal tibial cut is made using the planned proximal tibial cut angle.

Abstract: Methods and apparatus for planning and/or carrying out a total knee replacement surgical procedure on a knee of a leg of a patient are described. Anatomical data for the leg of the patient is obtained, which allows the femoral mechanical axis, the tibial mechanical axis and the joint line of the knee to be determined. A planned proximal tibial cut angle and a planned distal femoral cut angle are determined. A total knee replacement procedure is carried out on the knee of the patient, wherein a distal femoral cut is made using the planned distal femoral cut angle and a proximal tibial cut is made using the planned proximal tibial cut angle.

Abstract: Methods and apparatus for planning and/or carrying out a total knee replacement surgical procedure on a knee of a leg of a patient are described. Anatomical data for the leg of the patient is obtained, which allows the femoral mechanical axis, the tibial mechanical axis and the joint line of the knee to be determined. A planned proximal tibial cut angle and a planned distal femoral cut angle are determined. A total knee replacement procedure is carried out on the knee of the patient, wherein a distal femoral cut is made using the planned distal femoral cut angle and a proximal tibial cut is made using the planned proximal tibial cut angle.

Abstract: Methods and apparatus for planning and/or carrying out a total knee replacement surgical procedure on a knee of a leg of a patient are described. Anatomical data for the leg of the patient is obtained, which allows the femoral mechanical axis, the tibial mechanical axis and the joint line of the knee to be determined. A planned proximal tibial cut angle and a planned distal femoral cut angle are determined. A total knee replacement procedure is carried out on the knee of the patient, wherein a distal femoral cut is made using the planned distal femoral cut angle and a proximal tibial cut is made using the planned proximal tibial cut angle.

Abstract: A femoral instrument for use in the intramedullary canal is described and includes an intramedullary rod having a tip at a free end. A body is attached to the intramedullary rod and has a face with a bone abutting portion. A centralizer mechanism is located within the rod and is operable to deploy and retract a plurality of members to engage and disengage an inner surface of the intramedullary canal. The length of the intramedullary rod from the tip to the face of the body is less than 30 cm. The instrument can also include an angular adjustment mechanism. The angular adjustment mechanism can have a plurality of formations and can be rotated about the longitudinal axis of the intramedullary rod to present at least a one of the formations to abut a portion of the body to define the relative angle between the body and the intramedullary rod.

Abstract: A femoral instrument for use in the intramedullary canal is described and includes an intramedullary rod having a tip at a free end. A body is attached to the intramedullary rod and has a face with a bone abutting portion. A centraliser mechanism is located within the rod and is operable to deploy and retract a plurality of members to engage and disengage an inner surface of the intramedullary canal. The length of the intramedullary rod from the tip to the face of the body is less than 30 cm. The instrument can also include an angular adjustment mechanism. The angular adjustment mechanism can have a plurality of formations and can be rotated about the longitudinal axis of the intramedullary rod to present at least a one of the formations to abut a portion of the body to define the relative angle between the body and the intramedullary rod.

Abstract: A femoral instrument for use in the intramedullary canal is described and includes an intramedullary rod having a tip at a free end. A body is attached to the intramedullary rod and has a face with a bone abutting portion. A centraliser mechanism is located within the rod and is operable to deploy and retract a plurality of members to engage and disengage an inner surface of the intramedullary canal.

Abstract: A device and methods for use in determining the trajectory of a patella of a patient during a navigated knee replacement surgical procedure are described. The device includes a first component including a mounting for attachment to a posterior surface of the patient's patella and a second component having an outer surface presenting a formation adapted to engage with a femoral part of the patient's knee. A slider mechanism allows the second component to translate relative to the first component in a substantially medial-lateral direction of the patient when the first component is attached to the patient's patella. The device can be used in a method to help determine the medial-lateral position for a patella implant.

Abstract: A femoral instrument for use in the intramedullary canal is described and includes an intramedullary rod having a tip at a free end. A body is attached to the intramedullary rod and has a face with a bone abutting portion. A centraliser mechanism is located within the rod and is operable to deploy and retract a plurality of members to engage and disengage an inner surface of the intramedullary canal.

Abstract: A device and methods for use in determining the trajectory of a patella of a patient during a navigated knee replacement surgical procedure are described. The device includes a first component including a mounting for attachment to a posterior surface of the patient's patella and a second component having an outer surface presenting a formation adapted to engage with a femoral part of the patient's knee. A slider mechanism allows the second component to translate relative to the first component in a substantially medial-lateral direction of the patient when the first component is attached to the patient's patella. The device can be used in a method to help determine the medial-lateral position for a patella implant.

Abstract: A pressurizer device (1) is provided for maintaining pressure in the cement in a bone cavity during introduction of a prosthetic component, for example, a replacement hip stem. The pressurizer device (1) has a collar (4) and a hood (3). The hood (3) has a hoop (20) which arches across the central opening (14) of the collar (4). The hood (3) can be provided with or without a lining.

Abstract: A tamp assembly for use in configuring bone cavity filler material within a bone cavity, in preparation for receiving an implant, includes a distal tamp portion which has a substantially constant cross-section over at least part of its length. A proximal tamp portion has a through bore extending through it with a size which is such that the proximal tamp portion is a sliding fit over the distal tamp portion. The proximal tamp portion has an exterior tamping surface extending from the through bore which faces generally towards the distal tamp portion. The assembly includes a hammer for transmitting impact to the bone cavity filler material which is contacted by the tamping surface of the proximal tamp portion.

Abstract: A tamp assembly for use in configuring bone cavity filler material within a bone cavity, in preparation for receiving an implant, includes a distal tamp portion which has a substantially constant cross-section over at least part of its length. A proximal tamp portion has a through bore extending through it with a size which is such that the proximal tamp portion is a sliding fit over the distal tamp portion. The proximal tamp portion has an exterior tamping surface extending from the through bore which faces generally towards the distal tamp portion. The assembly includes a hammer for transmitting impact to the bone cavity filler material which is contacted by the tamping surface of the proximal tamp portion.

Abstract: A prosthetic component which can be in the form of a hip stem (1) is provided with a proximal portion (2) and a distal portion (4) terminating at a distal end (5). The distal portion (4) has at least two slots (6) disposed longitudinally in the distal portion (4). The distal portion (4) of the hip stem (1) has a hollow centre (8). The hip stem (1) can be compressed to expand the diameter of the distal portion (4) by buckling the legs (13) between the slots (6) in the form of a stent or Chinese lantern.

Abstract: A bone cavity sealing gasket which can be fitted over the resected end of a bone (2) to be provided with bone cement in its axial cavity, includes a sealing plate (10, 40) which has a quantity of a resiliently deformable material on its lower face to enable a seal to be created between the plate (10, 40) and the upper edge of the bone, and an opening (12, 42) extending through it. A plug (14, 30, 44) can be received in the opening (12,42) in the sealing plate (10, 40). The plug (14,30,44) has an injection port (26, 32) extending through it aligned with the opening (12, 42) in the sealing plate (10, 40) in which the injection nozzle (16) of bone cement delivery apparatus can be received.