Design

PE Insert (Cruciate Retaining)
PE Insert (Cruciate Substituting)
PE Insert (Cruciate Substituting - Ultracongruent)
Patellar Component

Femoral Component (standard)

All articular surfaces are precision ground under robotic control to achieve a precise and reproducible highly polished surface on every femoral component.

Designed in left and right versions, the patella shield is inclined in order to avoid excessive notching of the anterior femoral corticalis. The lateral shield has been slightly raised to protect against lateral patellar subluxation.

The patella groove is deep to prevent patellar subluxation ensuring full femoral-patellar contact up to 90° of flexion. The groove stops such that the posterior cruciate ligament can be retained if desired.

The femoral component has two pegs that are required for instrument referencing and contribute to the overall primary stability of the femoral component. From the medial-lateral view, both condyles are formed from a curve with a radius that diminishes from distal to dorsal.

The condylar surfaces are not flat in the medial to lateral direction but rather formed from multiple radii. This not only ensures that contact stresses are kept to a minimum but also tolerates slight misalignment of the components (int/external rotation and varus/valgus).

Femoral Component (Posterior Stabilized)

The external geometry of the posterior stabilized cruciate sacrificing femoral component (PS) is identical to the standard version with the exception of a centrally located box in which the post of the PE insert sits. The post and cam mechanism of the femoral component encourage correct kinematics in the absence of the cruciate ligaments.

Tibial Component

The tibial component is symmetric thereby eliminating the need for left and right versions. The inner surfaces that have contact with the PE insert are all polished to reduce PE wear.

On the bone side, the tibial component has cement pockets to capture the cement and maintain adequate cement mantle thickness.

The stem and plateau are manufactured from a single piece of material ensuring the highest resistance to repetitive loading forces.

Posterior and anterior recesses are designed to receive the snap-fit mechanism on the PE insert. A centrally located threaded hole gives an additional level of security by ensuring that the PE insert is securely fixed to the tibial component.

PE Insert (Cruciate Retaining)

The standard tibial PE insert has a symmetrical oval shape. A posterior cutout has been incorporated to allow for retention of the posterior cruciate ligament.

The shape of the articular surfaces are such that the PE contact stresses are minimized for the full range of normal knee motions and rotations up to ±15°.

A precise fit to the tibial component is ensured by the anterior and posterior snappers that lock into corresponding pockets during insertion. As an added measure of security, a centrally located hole allows the tibial component to be fixed with one screw to the tibial component.

PE Insert (Cruciate Substituting)

The cruciate substituting posterior stabilized PE insert has the same basic symmetric oval geometry as the cruciate retaining standard PE insert with all of the same snapper features and central screw hole. The posterior cutout is less marked since the posterior cruciate ligament is absent. A central post is added that contacts the interior of the femoral box providing the knee with femoral rollback and stability in the absence of the posterior cruciate ligament.

The articular surfaces exhibit a greater degree of congruency with the femoral condyles than in the case of the standard PE insert further reducing the contact stresses. Rotations up to ±10° are allowed.

PE Insert (Cruciate Substituting - Ultracongruent)

The cruciate substituting ultracongruent PE insert has the same basic symmetrical oval geometry as the cruciate retaining standard tibial PE insert and a centrally located screw hole. The posterior cutout is absent since the posterior cruciate ligament is absent.

The condylar surfaces exhibit the greatest degree of congruency with the femoral condyles to provide even lower contact stresses than exhibited in the standard and PS PE inserts.

Patellar Component

The basic patelar geometry is circular (axis-symmetric) with a raised center portion on the articular surface. On the opposite side are three pegs and an extensive cement pocket. The surgical technique allows for both only and inlay of the insert.