A method for registering one or more surfaces associated with a bone for implant revision procedures includes a digitizer used to digitize surface points on remaining cement, bone surfaces, or both. The bone is adapted to hold a primary implant and from which the primary implant was removed. The position of the one or more surfaces associated with bone is registered by computing at least one of: a generic set of one or more planes using the surface points or a best match between a known implant geometry and the surface points. A computer-assisted surgical system is also provided to execute the method.

A method includes obtaining a planned position of a first prosthetic component for implantation in a joint, obtaining positional data indicative of relative positions of bones of the joint, calculating, based on the positional data and the planned position of the first prosthetic component, a planned separation distance for the joint, facilitating adjustment of the planned position based on a desired separation distance by updating the planned separation distance in response to an adjusted planned position of the first prosthetic component, and guiding installation of the first prosthetic component in the joint in the adjusted planned position.

The present disclosure discloses an artificial femoral prosthesis (100) for knee arthroplasty, a tibial prosthesis (150), a medial femoral unicompartmental prosthesis (201), a lateral femoral unicompartmental prosthesis (301), and a femoral trochlear prosthesis (401). The femoral prosthesis (100) comprises: a medial condyle portion (51) and a medial trochlear portion (131), wherein an articular surface of the medial condyle portion appears in a sagittal section as an arc of a first ellipse (38), and an articular surface of the medial trochlear portion appears in the sagittal section as an arc of a second ellipse or circle (40); and lateral members (91, 141), comprising a lateral trochlear portion (141) and a lateral condyle portion (91), wherein an articular surface of the lateral trochlear portion appears in the sagittal section as an arc of a third ellipse or circle (80), and an articular surface of the lateral condyle portion appears in the sagittal section as an arc of a fourth ellipse (78). The prostheses according to the above embodiments of the present disclosure can better conform to geometric shapes of normal femoral condyles of humans, thereby simplifying greatly design of parameter values for different models of femoral prostheses.

This invention relates to a positioning template used to determine correct cutting planes and angles and drilling positions during surgical procedures, and more particularly, but not exclusively, to a femoral cutting template (10) used in the preparation of a femoral condyle during a unicondylar knee arthroplasty (UKA). The femoral cutting template (10) comprises attachment means (12) for releasably attaching the template to a tibiofemoral spacer shim (50), provided between a proximal tibia and a femoral condyle. The template further comprises a main body (14) defining first and second guide apertures (16,18) for guiding first and second tools respectively. The first and second tools are used for creating first and second receiving formations (206,208), in the femoral condyle, which are created for receiving first and second parts of a femoral component forming part of an unicondylar knee prosthesis.

A method of evaluating a human knee joint, includes: cutting away a proximal portion of the tibia; inserting the gap tensioner between the tibia and the femur; extending the gap tensioner urging the tibia and the femur apart and applying tension to the medial and lateral collateral ligaments; associating at least two tracking markers with the knee joint; providing an electronic receiving device operable to determine a position and orientation of each of the tracking markers relative to the electronic receiving device; moving the knee joint through at least a portion of its range of motion; while moving the knee joint, using the electronic receiving device to collect position data from the tracking markers; processing the collected position data to produce a geometric model of at least a portion of the knee joint; and computing one or more tool paths passing through the knee joint.

A surgical kit and method for milling a bone, the surgical kit including: a rotatable milling tool including a receiving bore with an abutment portion; a positioning pin insertable in the bone for guiding the milling tool along a milling axis and towards the bone, the positioning pin including a pin shaft receivable in the receiving bore and a pin depth determination element, the pin shaft being abuttable against the abutment portion of the milling tool; and a bone milling guide positionable at a predetermined location on the bone for guiding the positioning pin when the positioning pin is inserted into the bone, the bone milling guide including a pin shaft guiding channel for receiving the pin shaft and a guide depth determination element cooperable with the pin depth determination element to provide an indication that the positioning pin is inserted in the bone at a predetermined depth.

A system for repairing a defect on an articular surface of a patient's trochlear region, the system comprising a guide block comprising a body having an exterior surface configured to engage with the saddle portion and ridge portions of the patient's trochlear region, a protrusion extending generally from the body and configured to be received in a first bore formed in the articular surface along a reference axis, and a first cavity extending through the body configured to establish a first working axis displaced from the reference axis, wherein the exterior surface of the body and the protrusion are configured to secure the location of the guide block about the patient's trochlear region. A method for preparing an implant site in bone, comprising: establishing a reference axis extending from the bone; creating a bore in the bone by reaming about the reference axis; securing a guide block about the articular surface; establishing a first working axis extending from the bone using the guide block, the first working axis is displaced from the reference axis; and creating a first socket in the bone by reaming about the first working axis, wherein the first socket partially overlaps with the bore.

Certain embodiments generally provide an improved tibial base member comprising keel portions that allow one or both cruciate ligaments to be preserved. Other embodiments provide improved lateral and/or medial inserts having a mesial lip that helps relieve and or prevent impingement between the femoral component and the tibial eminence. Other embodiments provide improved femoral components having various chamfers to provide additional clearance with respect to the tibial eminence and posterior cruciate ligament without decreasing bone coverage.

A system for a unicompartmental knee replacement is described. The system can include a femoral prosthesis component, a tibial prosthesis component and a meniscal bearing. The meniscal bearing can be insertable between the femoral prosthesis component and the tibial prosthesis component. The meniscal bearing can include a first bearing surface configured to bear against the femoral prosthesis component, a second bearing surface opposed to the first bearing surface and configured to bear against the tibial prosthesis component, and a sidewall separating the first bearing surface from the second bearing surface, wherein the sidewall has a retention groove formed in a portion thereof, and wherein the meniscal bearing and the tibial prosthesis component are configured such that the retaining flange enters the retention groove on movement of the meniscal bearing relative to the tibial prosthesis component towards the medial wall.

An example implant device includes a base having a surface that mates with bone, and a plurality of tapered protrusions positioned on the base and extending from the surface of the base that mates with bone. A surface of the plurality of tapered protrusions includes a textured surface to increase area for bone growth. An example method for inserting the implant device into bone includes forcing the plurality of tapered protrusions of the implant device into the bone, and securing the implant device in place without cement due to the plurality of tapered protrusions cutting into the bone for fixation of the implant device.