Medacta Corporate

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GMK KNEE REVISION SYSTEM 
THERE ARE NO IMPOSSIBLE CHALLENGES


The entire GMK Total Knee Replacement System has been designed to preserve the joint functionality without dramatically altering its anatomy and kinematics, even in cases of severe ligament instability or massive bone defects.

Thanks to the GMK Revision comprehensive range of options  the surgeon can choose the most suitable solution for every patient within his care without any compromise.

The established GMK REVISION implant, along with the easy to use instrumentation, help the surgeon to operate every day in total confidence, flawlessly addressing each surgical scenario, from primary augmentable cases to the most challenging knee revisions: with GMK REVISION any challenge is possible!

 

  1. Cemented and mechanically attached tibial augmentation can selectively address asymmetric bone defects
  2. Tibial inlays are available both on fixed and mobile versions with different levels of constraint to provide the maximum intra-operative flexibility.
  3. Besides the traditional symmetric inset patella, GMK Revision also offers the asymmetric resurfacing patella, increasing the patella-femur contact surface, reducing stress on polyethylene and improving stability.
  4. GMK Revision femoral component is bone preserving: the reduced box fits both posterior-stabilised and semi-constrained inlays therefore eliminating large bone loss.
  5. Same internal and articular profiles as GMK Primary femur ensures the freedom to choose intra-operatively the most suitable solution for the patient.
  6. Distal and posterior femoral augmentation mechanically attached to the femoral component help to fill condylar bone defects, accurately managing the joint line position and the flexion/extension gaps.
  7. 360° adjustable tibial and femoral offsets maximise bone coverage without compromise, reducing the risk of overhang.
  8. All the modular connections are tested and dedicated instruments are available in the operating room to standardise the procedure, providing every patient with the maximum level of safety.
  9. A complete range of extension stems is available when intramedullary fixation is required. Stems are available in a wide range or sizes and in cementless or cemented and are interchangeable between femur and tibia to minimise the OR inventory.

The GMK Revision product range, including mobile and fixed bearings, offers different levels of constraint:

  • Cruciate retaining
  • Ultracongruent
  • Posterior-stabilized
  • Varus/valgus constrained

STANDARD FEMORAL COMPONENT

6 sizes
Anatomical: left and right
Material: Cobalt-Chrome (Co-Cr-Mo ISO 5832-4)
Cemented

POSTERIOR-STABILISED FEMORAL COMPONENT

6 sizes
Anatomical: left and right
Material: Cobalt-Chrome (Co-Cr-Mo ISO 5832-4)
Cemented

FIXED TIBIAL COMPONENT

6 sizes
Anatomical: left and right
Material: Cobalt-Chrome (Co-Cr-Mo ISO 5832-4)
Cemented

MOBILE TIBIAL COMPONENT

6 sizes
Anatomical: left and right
Material: Cobalt-Chrome (Co-Cr-Mo ISO 5832-4)
Cemented

ULTRACONGRUENT FIXED INLAY

Symmetric, deep dish
Anterior flare to accommodate patellar tendon
6 sizes
Five levels of thickness (10, 12 ,14, 17, 20 mm)
Machined Ultra High Molecular Weight Polyethylene (UHMWPE ISO 5834-2)

POSTERIOR-STABILISED FIXED INLAY

Symmetric
Anterior flare to accommodate patellar tendon
6 sizes
Five levels of thickness (10, 12 ,14, 17, 20 mm)
Additional fixation screw
Machined Ultra High Molecular Weight Polyethylene (UHMWPE ISO 5834-2)

SEMI-CONSTRAINED FIXED INLAY

Symmetric
Anterior flare to accommodate patellar tendon
6 sizes
Seven levels of thickness (10, 12 ,14, 17, 20, 23, 26 mm)
Additional fixation screw
Machined Ultra High Molecular Weight Polyethylene (UHMWPE ISO 5834-2)

STANDARD MOBILE INLAY (CRUCIATE RETAINING)

Symmetric
Anterior flare to accommodate patellar tendon
6 sizes
Five levels of thickness (10, 12 ,14, 17, 20 mm)
Machined Ultra High Molecular Weight Polyethylene (UHMWPE ISO 5834-2)

ULTRACONGRUENT MOBILE INLAY

Symmetric, deep dish
Anterior flare to accommodate patellar tendon
6 sizes
Five levels of thickness (10, 12 ,14, 17, 20 mm)
Machined Ultra High Molecular Weight Polyethylene (UHMWPE ISO 5834-2)

OFFSET ADAPTER

Interchangeable femur / tibia
2 offset: 3 , 5 mm
Titanium alloy (Ti6Al4V, ISO 5832-3)

CEMENTLESS EXTENSION STEM

Interchangeable femur / tibia
Diameter = 11, 13, 16, 19, 22 mm
Length = 65, 105, 150 mm
Titanium alloy (Ti6Al4V, ISO 5832-3)

CEMENTED EXTENSION STEM

Interchangeable femur / tibia
Fluted shape
Diameter = 11, 13, 16 mm
Length = 65, 105 mm
Titanium alloy (Ti6Al4V, ISO 5832-3)

DISTAL FEMORAL AUGMENTATION

Mechanically attached to femoral component (screw included)
Interchangeable medial / lateral side
Three levels of thickness: 4,8,12 mm
High nitrogen Stainless steel (M30NW, ISO 5832-9) and Titanium alloy (Ti6Al4V, ISO 5832-3)

POSTERIOR FEMORAL AUGMENTATION

Mechanically attached to femoral component (screw included)
Interchangeable medial / lateral side
Two levels of thickness: 5, 10 mm
High nitrogen Stainless steel (M30NW, ISO 5832-9) and Titanium alloy (Ti6Al4V, ISO 5832-3)

TIBIAL AUGMENTATION

Cemented to tibial component
Interchangeable medial / lateral side
Two levels of thickness: 5, 10 mm
Titanium alloy (Ti6Al4V, ISO 5832-3)

RESURFACING PATELLA

Anatomical shape
4 sizes
Machined Ultra High Molecular Weight Polyethylene (UHMWPE ISO 5834-2)
Cemented
Three fixation pegs

INSET PATELLA

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

The femoral box is reduced to a minimum, saving precious bone stock.

SEMI-CONSTRAINED FIXED  INLAY
 

MECHANICAL PROPERTIES

The internal reinforcement metal peg provides resistance and safety. Mechanical tests show proven stability and mechanical resistance of GMK REVISION semi-constrained inlay*.  Residual freedom ensures varus/valgus and torsional accommodation.

*Data on file: Medacta

 


POLYETHYLENE

Published papers show that polyethylene that does not undergo any irradiation or thermal treatments, that may affect mechanical properties, may show reduced potential of delamination[1]. Medacta provides machined, non-irradiated polyethylene for all GMK tibial inserts.

Read more 

 

BONE PRESERVING AUGMENTABLE TIBIAL COMPONENT

Both for mobile and fixed bearing, the internal surface of the tibial baseplate is mirror polished, minimising the risk of backside wear.
The keel dimensions are the same as for GMK PRIMARY, allowing for the use of a modular offset.
Cemented augments are available to fill bone defects and  manage the joint line position.

Interchangeable modular offset adapters are available for femur and tibia in order to provide the maximum flexibility with the minimum inventory, avoiding the need for additional offseted stems.
All the modular connections are accurately tested* and dedicated instruments are available in the operating room to ensure a reproducible fixation and providing the maximum safety for the patient.

  *Data on file: Medacta

Due to different clinical indications,  both cementless and cemented options are available. Cementless stems have longitudinal splines to provide rotational stability, whereas cemented stems have longitudinal pockets for cement and fluted shape to facilitate insertion.

ADD EASY-TO-USE AND SAFE INSTRUMENTATION TO A VERSATILE RANGE OF PRODUCT: THE RESULT IS GMK REVISION
The primary goal of a GMK Revision knee replacement includes the restoration of anatomical alignment and functional stability, the accurate re-establishment of the joint line and the fixation and stabilisation of the revision prosthetic implant components.

The GMK Revision has flexible instrumentation which allows different surgical techniques to be performed, depending on the surgeon's preferences and the clinical circumstances. The surgeon can therefore proceed with complete confidence even in the most challenging situation.

NO COMPROMISES ON SAFETY

Dedicated instruments are provided to accurately reproduce the validated offset on femur and tibia. All the modular connections are then secured by Morse taper, additional screw, dynamometric wrenches and special impactors which always ensure a standardised and reproducible procedure.

MICROMETRIC ADJUSTMENT OF THE RESECTION LEVEL TO SAVE BONE STOCK

Tibial and femoral resections can be accurately fine-tuned thanks to micrometric systems, in order to preserve as much bone as possible and  ensuring an optimal joint line management.

STRAIGHTFORWARD JOINT LINE MANAGEMENT

Multiple checks at different operative stages allows the management of the joint line position in order to restore the best functionality of the extensor mechanism. Patellar tracking can be adjusted up to the femoral trialing step as femoral augment resections can be performed  directly through the trial femur.

INTRA-OPERATIVE FLEXIBILITY THANKS TO THE CROSSOVER TECHNIQUES

The instruments provided easily allow the surgeon to switch, intra-operatively, from a less constrained to a more constrained inlay when more stability is required, without the need for any additional instrumentation.

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

GMK PRIMARY AND GMK REVISION SYNERGY

Same internal and articular femoral profiles between GMK REVISION and GMK PRIMARY ensure the freedom to choose intra-operatively the most suitable constraint for the patient, even after the bone cuts have been performed.

In addition, the wide compatibility of the primary polyethylene inlay and using the same primary tibial component results in less inventory for the hospital.