NexGen® CR-Flex Fixed Bearing Knee
THE SPECIFIC DEMANDS OF THE CR SURGEON
Specifically designed for the CR surgeon, the CR-Flex Knee represents an
enhancement of the highly successful NexGen CR Knee. It's a good
choice for CR patients because it offers new design elements that address
not only high flexion, but many of the important issues faced by CR
surgeons. For example, consider the knee that is tight in flexion and
acceptable in extension. CR-Flex offers Minus size femoral components
which are 2mm smaller in the A/P dimension. Without removing additional
bone, the Minus size options help the CR surgeon balance the flexion and
extension gaps.
Click to learn more about Minus Sizing Options.
ACCOMMODATING FLEXION TO 155° WITH KINEMATIC ROLLBACK
With traditional TKA designs, the contact area between the posterior femoral condyles and the tibial articular surface decreases as the knee moves into flexion angles higher than 125˚. Also, with some designs, high flexion may be somewhat limited by impingement of the quadriceps mechanism on the front of the tibial articular surface.
Specific design features of the CR-Flex Knee help maintain adequate tibiofemoral contact during high flexion and provide greater clearance for the patellar tendon. These features allow the kinematics of the NexGen CR design to continue into deep flexion angles.
Click to learn more about Enhanced CR-Flex Design Features.
TIBIOFEMORAL KINEMATICS
Asymmetrical femoral condyles work in concert with the PCL to facilitate
normal asymmetric rollback of the femur on the tibia during flexion.1
The lateral distal radius of CR-Flex is extended posteriorly to further aid
natural anteroposterior rollback when the PCL is present.
References:
1. Bertin KC, Komistek RD, Dennis DA, Hoff WA, Anderson DT, Langer T. In vivo determination of posterior femoral rollback for subjects having a NexGen posterior cruciate-retaining total knee arthroplasty. J Arthroplasty. December, 2002;17(8):1040-1048.
