The PS version of the Rolflex TONIC system includes a stabilization by cam and post in an intercondylar “open box” design. Especially, the design and the positioning of the cam and post was studied to preserve the native bone with a minimal resection at the anterior intercondylar section.
The PS Rolflex TONIC presents a rounded shape postero-stabilization cam which is positioned very low and very posterior with regard to the distal and posterior condyles.
The mechanism of stabilization engages from 47° of flexion. The round shapes of the cam and post contact enables a freedom of rotation between the 2 components while preserving an important congruence. The contact initates at the top of the tibial post and lowers progressively to reduce the effect of the anterior forces generated by the femur on the tibia. Beyond 120° of flexion, the most posterior edge of the posteroro-stabilization cam leads to the decoaptation of the lateral condyle, characteristic of the large flexion.
PS Rolflex TONIC was not designed as a “hi-flex” prosthesis, but is respectful of the natural phisiology of the knee joint. Whenever the patient is able of bending, PS Rolflex TONIC will not block him (her) in his return to the function.