Medacta Corporate

All in one

MORE THAN
15 YEARS OF CLINICAL SUCCESS

Evolis implant and instruments have been developed in collaboration with a group of experienced orthopaedic surgeons making possible to successfully realize thousands of knee arthroplasties worldwide, including Europe, USA, Australia and Japan.

The Evolis concept is based on 3 main features:

  • A compact, easy and well designed ancillary which allows an accurate, fast and reproducible surgical act, offering at the same time several operative choices as well as checks during surgery.
  • Both implant design and product range are the result of a morphometric study aimed at the optimization of bone-implant surfaces.
  • The choice of common profiles allows interchangeability of the sizes without compromising on maximal metal - polyethylene contact surfaces.

 

  1. Bone preserving design: minimum condylar resections and posterior-stabilised version without any need for a box
     
  2. Anatomic design of the trochlea optimises the patellar tracking, reducing stress on patellar tendon and the risk of patella dislocation
     
  3. J-curved sagittal profile allows more natural knee kinematics, improves knee flexion and promotes rollback of the femoral component
     
  4. Different cemented tibial extension stem options are available when further stabilisation in needed

 

STANDARD FEMORAL COMPONENT

6 sizes
Anatomical: left, right
Material: Cobalt-Chrome (Co-Cr-Mo ISO 5832-4)
Cemented: 0.5 mm deep pockets
Cementless: Porous Titanium coating

POSTERIOR-STABILISED FEMORAL COMPONENT

6 sizes
Anatomical: left, right
Material: Cobalt-Chrome (Co-Cr-Mo ISO 5832-4)
Cemented: 0.5 mm deep pockets
Cementless: Titanium plasma sprayed coating (ASTM F 1580)

TIBIAL BASEPLATE

6 sizes
Symmetric
Material: Titanium alloy (Ti6Al4V ISO 5832-3)
Cemented: 0.5 mm deep pockets
Cementless: Titanium plasma sprayed coating (ASTM F 1580)
Cementless: 4 screws holes (not required with cement): Ø 6.5 mm; 6 lengths : 20, 25, 30, 35, 40, 45 mm

TIBIAL EXTENSION STEM

Extension stem connection: Ø 12 mm ; 2 lengths: 30, 60 mm
Material: Titanium alloy (Ti6Al4V ISO 5832-3)

STANDARD INSERT

6 sizes
Five levels of thickness: 9, 11, 13, 16, 19 mm
Machined Ultra High Molecular Weight Polyethylene (UHMWPE ISO 5834-2)

ULTRACONGRUENT INSERT

6 sizes
Five levels of thickness: 10, 12 ,14, 17, 20 mm
Machined Ultra High Molecular Weight Polyethylene (UHMWPE ISO 5834-2)

POSTERIOR-STABILISED INSERT

6 sizes
Five levels of thickness: 9, 11, 13, 16,19 mm
Machined Ultra High Molecular Weight Polyethylene (UHMWPE ISO 5834-2)

RESURFACING PATELLA

Symmetric shape, 3 fixation peg
4 sizes
Machined Ultra High Molecular Weight Polyethylene (UHMWPE ISO 5834-2)
Cemented

INSET PATELLA

Symettric shape, one central fixation peg
3 sizes
Machined Ultra High Molecular Weight Polyethylene (UHMWPE ISO 5834-2)
Cemented

BONE PRESERVING POSTERIOR-STABILISED FEMORAL COMPONENT

The posterior-stabilised femoral component is completely boxless, thus preserving bone.
Mechanical tests show that a good level of ROM and A/P stability is provided by the cam-post mechanism adopted by the Evolis PS version.*

*Data on file: Medacta

ANTI-NOTCHING ANTERIOR CUT

The 4° sloped anterior cut creates a wedge effect that improves primary stability and reduces the risk of anterior notching.

SAFE INSERT FIXATION MECHANISM

The inlay clipping mechanism assures time-effective and safe implantation avoiding sliding, deformation and risk of dislocation.
An additional fixation screw for the posterior-stabilised insert provides further mechanical resistance. The mechanical tests performed demonstrate  the safety of Evolis posterior-stabilised inlay.*

*Data on file: Medacta

WIDE FEMORAL-TIBIAL SIZE MATCHING

Thanks to the wide size matching between femoral and tibial component, Evolis provides to the surgeon a big flexibility in obtaining the maximum bone coverage without compromises.

POLYETHYLENE INSERT

MATERIAL
The Evolis polyethylene inserts, as all the Medacta GMK tibial inserts, do not undergo any irradiation or thermal process that can affect the mechanical properties and the oxidative stability of the material. This ensures the best maintenance of mechanical properties which is crucial to reduce the delamination process[1], the main cause of polyethylene failure in total knee arthroplasty.[2]

*The value refers to a non-irradiated polyethylene with characteristics similar to those of GMK inserts polyethylene.

Figure 1: Modulus (defined as the ratio of tensile stress to tensile strain) for non-irradiated and cross-linked polyethylene.
Subsequent melt stabilisation for cross-linked polyethylene was performed at 170°C. Adapted from Baker et al.[3]

*The value refers to a non-irradiated polyethylene with characteristics similar to those of GMK inserts polyethylene.

Figure 2: Yield stress (MPa) for non-irradiated and cross-linked polyethylene. Subsequent melt stabilisation for cross-linked
polyethylene was performed at 150°C. Adapted from Muratoglu et al.[4]

*The value refers to a non-irradiated polyethylene with characteristics similar to those of GMK inserts polyethylene.

Figure 3: Ultimate tensile strength (MPa) for non-irradiated and cross-linked polyethylene. Subsequent melt stabilisation for
cross-linked polyethylene was performed at 150°C. Adapted from Muratoglu et al.[4]

 

Learn more about Medacta polyethylene: Polyethylene in TKA: Do we really need cross-linked polyethylene?, MORE Journal Vol. 1 May 2011.[5]

EVOLIS INSTRUMENTATION: ALL IN ONE!
The key instruments of Evolis instrumentation is the femoral 30in1 cutting block, providing various benefits:

  • Time saving
  • Easy to use
  • Reproducible surgical act
  • Reduced instrumentation: only 2 trays!

For tibial step, both intra- and extra-medullary options are available to match every surgeon’s preferences

DESIGN RATIONALE
[1] Ries M D, “Highly Cross-Linked Polyethylene. The Debate is Over-In Opposition”, The Journal of Arthroplasty, 20:59-62, 2005.
[2] Kondo et al. “Arthroscopy for evaluation of polyethylene wear after total knee arthroplasty”, J Orthop Sci, 13:433-437, 2008. Orthop Sci, 13:433-437, 2008
[3] Baker et al., “The effects of degree of Crosslinking on the fatigue crack initiation and propagation resistane of orthopedic-grade polyethylene”, J Biomed Mater Res A, 66(1):146-54, 2002.
[4] Muratoglu et al., “Unified wear model for highly crosslinked ultra-high molecular weight polyethylenes (UHMWPE)”, Biomaterials, 20:1463-70, 1999.
[5] Polyethylene in TKA: Do we really need cross-linked polyethylene?, MORE Journal Vol. 1 May 2011

 

CLINICAL STUDIES
[6] Bouchet, Dufour, Lepage, Olivier, Toesca, Clinical and radiological evaluation up to 5 years, study report

EVOLIS AND GMK SINERGY
As the GMK and Evolis femoral internal profiles are the same, the Evolis 30in1 cutting block is available as an additional option to implant GMK PRIMARY.