All in one
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:
6 sizes
Anatomical: left, right
Material: Cobalt-Chrome (Co-Cr-Mo ISO 5832-4)
Cemented: 0.5 mm deep pockets
Cementless: Porous Titanium coating
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)
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
Extension stem connection: Ø 12 mm ; 2 lengths: 30, 60 mm
Material: Titanium alloy (Ti6Al4V ISO 5832-3)
6 sizes
Five levels of thickness: 9, 11, 13, 16, 19 mm
Machined Ultra High Molecular Weight Polyethylene (UHMWPE ISO 5834-2)
6 sizes
Five levels of thickness: 10, 12 ,14, 17, 20 mm
Machined Ultra High Molecular Weight Polyethylene (UHMWPE ISO 5834-2)
6 sizes
Five levels of thickness: 9, 11, 13, 16,19 mm
Machined Ultra High Molecular Weight Polyethylene (UHMWPE ISO 5834-2)
Symmetric shape, 3 fixation peg
4 sizes
Machined Ultra High Molecular Weight Polyethylene (UHMWPE ISO 5834-2)
Cemented
Symettric shape, one central fixation peg
3 sizes
Machined Ultra High Molecular Weight Polyethylene (UHMWPE ISO 5834-2)
Cemented
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
The 4° sloped anterior cut creates a wedge effect that improves primary stability and reduces the risk of anterior notching.
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
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.
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:
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.
