Abstract: A femoral knee implant includes a fourth compartment of articulation. The superior posterior articulating surface is achieved by first increasing the thickness of the superior posterior condylar portion of the femoral component to widen the superior posterior edge of the posterior condyle. Second, the newly created surface at the superior posterior condyle is smoothly rounded to provide an articular surface with no sharp changes in the surface contours. In one embodiment, the fourth articular compartment of this invention is provided in a one piece femoral design. In another embodiment, it is provided as a modular addition to an existing prior art femoral component. In another embodiment, the fourth compartment is combined with a posterior stabilized (PS) TKR design that includes a tibial post and cooperating femoral cam characterized by low engagement of the cam on the spine.

Abstract: A femoral knee implant includes a fourth compartment of articulation. The superior posterior articulating surface is achieved by first increasing the thickness of the superior posterior condylar portion of the femoral component to widen the superior posterior edge of the posterior condyle. Second, the newly created surface at the superior posterior condyle is smoothly rounded to provide an articular surface with no sharp changes in the surface contours. In one embodiment, the fourth articular compartment of this invention is provided in a one piece femoral design. In another embodiment, it is provided as a modular addition to an existing prior art femoral component. In another embodiment, the fourth compartment is combined with a posterior stabilized (PS) TKR design that includes a tibial post and cooperating femoral cam characterized by low engagement of the cam on the spine.

Abstract: A notch/chamfer guide has chamfer and trochlear recess cutting slots and a notch, corresponding to the intercondylar box of a femoral implant, with a removable notch slot attachment. With the notch slot attachment assembled to the cutting guide adjacent the notch, blade receiving slots are defined between the notch slot attachment and the inside walls of the notch. The slots provide control to the saw blade to prevent the blade from angling away from the notch walls and making imprecise cuts. The notch slot attachment is removable to allow easy access to the notch area so that a manual instrument such as an osteotome can be used for final removal of the notch bone and to facilitate the use of an oscillating saw in the chamfer slots of the guide. A U-shaped notch is provided for cutting a trochlear recess that will lie behind the anterior portion of the implanted knee component to receive the backside of the patellar track of the implant.

Abstract: A set of instruments and a surgical technique facilitate precise orientation of the femoral implant. Precision is aided by decoupling the determination of A/P placement, valgus angle, and external rotation into three discrete steps. In this way, a surgeon's full concentration can be directed to each element of placement and fine adjustments can readily be made to each. An Epicondylar Guide is configured to ease referencing external rotation from the epicondyles. The narrow elongated guide is easily alignable with the epicondyles when it is placed on the flat distal cut. A Posterior Reference/Rotation Guide can be attached to the Epicondylar Guide to check the rotation relative to the intact posterior condyles to confirm the epicondylar setting. A slot in the guide guides a saw blade to cut a corresponding slot in the distal femur. An A/P Cutting Guide has a fin that fits in the slot cut in the distal femur.

Abstract: A tibial knee component includes reference marks to which a surgeon can reference the location of the point of contact between the tibial component and a femoral knee component. In one embodiment of the invention, the femoral component also includes reference marks to aid the surgeon in determining the contact point and to aid in orienting the knee in specific predetermined degrees of flexion.

Abstract: A tibial knee component includes reference marks to which a surgeon can reference the location of the point of contact between the tibial component and a femoral knee component. In one embodiment of the invention, the femoral component also includes reference marks to aid the surgeon in determining the contact point and to aid in orienting the knee in specific predetermined degrees of flexion.

Abstract: A patella cutting clamp comprises a pair of jaw members joined together in scissors-like relation for pivotal movement relative to each other about a pivot axis intermediate their ends. Each jaw member has a handle portion extending in one direction from the pivot axis and a jaw portion extending in the other direction. The jaw portions have edges facing each other that are shaped for engagement with opposite borders of a patella. Teeth along the patella-gripping edges grip and hold the patella firmly. Saw guide slots in the jaw portions lying in a common plane guide the saw when the saw cut is made. A patella elevator member is attached to the jaw members for movement along the pivot axis and has a platform portion adapted to engage the anterior aspect of the patella. A mechanism is provided for establishing and maintaining a predetermined position of the elevator member relative to the jaw members and thereby positioning the patella at a predetermined position relative to the saw guide slots.

Abstract: A box-like recess between the condylar portions of the femoral component has a transverse convexly curved cam follower portion at the posterior extremity of a superior wall which engages a concave cam surface at the inferior portion of the posterior surface of a tibial post that extends up from the plateau surface of the tibial component into the recess. The camming action between the cam follower and cam surface forces the zones of contact between the condylar portions of the femoral component and concavities in the tibial component posteriorly as the leg approaches full flexion, thereby increasing the range of flexion without interference between posterior surfaces of the femur and the tibial component and preventing anterior dislocation of the femur. The plateau of the tibial component slopes inferiorly and posteriorly, also to increase the range of flexion without interference.

Abstract: A knee joint prosthesis comprises a femoral component having laterally spaced-apart condylar portions shaped to match generally the shapes of the condylar surfaces of the femur and a tibial component having a plate-like platform portion which includes laterally spaced-apart concavities in the external surface, each of which receives and supports one of the condylar portions of the femoral component in all positions of the leg. The femoral component has a box-like intercondylar portion interconnecting the condylar portions and defining an intercondylar recess which receives a post that extends upwardly from the tibial component. At and near full extension of the leg, any tendency for posterial dislocation of the femur results in engagement between the anterior surfaces of the post and recess to prevent posterial dislocation of the femoral component relative to the tibial component.