Medacta GMK Sphere Surgical Technique
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Medacta GMK Sphere Surgical Technique

Medially stabilized knee. calipered kinematic alignment
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Surgical Technique
Joint
Spine
Sports Med
CALIPERED KINEMATIC ALIGNMENT

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Summary of Contents for Medacta GMK Sphere

  • Page 1 Surgical Technique Joint Spine Sports Med CALIPERED KINEMATIC ALIGNMENT...

  • Page 2: Table Of Contents

    GMK Sphere Calipered Kinematic Alignment Surgical Technique INDEX INTRODUCTION Kinematic Alignment approach Indications Contraindications Surgical Approach TIBIO-FEMOR AL OFFSET MEASUREMENT DISTAL FEMOR AL RESECTION Placing the Intramedullary Rod Positioning the Distal Cutting Guide ANTERIOR CUT, POSTERIOR CUT AND CHAMFER Femoral Sizing...

  • Page 3: Table Of Contents

    10. PATELL A 11. SELECTION OF THE PROSTHETIC COMPONENTS - SIZE MATCHING 12. FINAL IMPL ANT 12.1 Tibial implant 12.2 Insert 12.3 Femoral implant 12.4 Patella 13. ANNEX 1 UNSLOTTED GUIDE COMPATIBILIT Y 13.1 Distal femoral resection 13.2 Proximal tibial resection 14.

  • Page 4: Introduction

    The GMK Sphere is designed for cemented use in total knee arthroplasty, if there is evidence of sufficient sound EXAMPLE: In a varus knee there is typically cartilage wear bone to seat and support the components.

  • Page 5: Contraindications

    2. TIBIO-FEMOR AL OFFSET MEASUREMENT When using a GMK Sphere CR insert, the measurement of the tibio-femoral offset can be a reference to check the slope once the trial implants are in place. Flex the knee to 90°.

  • Page 6: Distal Femor Al Resection

    GMK Sphere Calipered Kinematic Alignment Surgical Technique 3. DISTAL FEMOR AL RESECTION Calipered kinematic alignment sets the femoral component Determine the extent of cartilage wear on each distal coincident to the distal articular surface of the native femur. femoral condyle. Use a ring curette to remove any partially Restoring the native distal femoral line requires worn cartilage on the bone.

  • Page 7: Positioning The Distal Cutting Guide

    6.0 ± 0.5 mm. These values equal the 9 block by releasing the lever. mm thickness of the distal condyles of the GMK Sphere femoral component after compensating for the ~1 mm kerf of the saw blade and 2 mm of worn cartilage when...

  • Page 8: Anterior Cut, Posterior Cut And Chamfer

    GMK Sphere Calipered Kinematic Alignment Surgical Technique In cases of a 1 mm under-resection, refine the cut through If one or both condyles have been over-resected by 1 or 2 the slot of the distal cutting block. mm, the correct joint line level is restored using dedicated washers, as described in the next section.

  • Page 9: In1 Cutting Block Positioning

    To measure the size of the femur: 1. The stylus should contact the anterior ridge of the lateral femoral cortex. 2. The posterior plates should be in contact with both the medial and lateral posterior femoral condyles. The size can be read on the front of femoral sizer. 4IN1 CUTTING BLOCK POSITIONING Option 1: Posterior Pegs Once the size has been established, drill through the...
  • Page 10 GMK Sphere Calipered Kinematic Alignment Surgical Technique OPTION To apply the washer, slide it over the posterior peg of the 4in1 block until it contacts the flat surface of the back of To achieve further stabilization, insert two pins into the the 4in1 block.
  • Page 11 Select the 4in1 block which corresponds to the size CAUTION previously determined. Slide the 4in1 block over the pins through the corresponding row of parallel positioning holes It is strongly recommended not to impact or hammer the until it contacts the distal resection. 4in1 guide with a mallet.

  • Page 12: Posterior Cut, Anterior Cut And Chamfers

    5.0 ± 0.5 mm. These values equal the 8 block cuts will not result in anterior notching of the femur. mm thickness of the posterior condyles of the GMK Sphere femoral component after compensating for the ~1 mm...

  • Page 13: Tibial Resection

    5. TIBIAL RESECTION Calipered kinematic alignment sets the tibial component parallel to the flexion-extension axis of the native knee and coincident with the plane of the native tibia, which means restoring the varus-valgus and the slope, after compensating for cartilage and bone wear. MARK THE A/P AXIS ON THE TIBIA On the lateral tibial condyle, mark the anterior-posterior axis (blue line) of the almost elliptically-shaped boundary of the...

  • Page 14: Setting The Tibial Varus/Valgus With The Extramedullary Guide

    GMK Sphere Calipered Kinematic Alignment Surgical Technique Select the tibial slotted cutting guide which corresponds to SETTING THE TIBIAL VARUS/VALGUS WITH the operative side (left or right). Fix the slotted tibial cutting THE EXTRAMEDULLARY GUIDE guide to the extramedullary eyeballing superior guide using the set screw provided (black circle).

  • Page 15: Setting The Tibial Resection Level With The Extramedullary Guide

    SETTING THE TIBIAL RESECTION LEVEL WITH REMOVING THE EXTRAMEDULLARY GUIDE THE EXTRAMEDULLARY GUIDE Remove the stylus by pulling it upwards (1). Unlock the Fix the tibial stylus into the dedicated hole on the cutting frontal screw of the extramedullary guide body (2). Open guide.
  • Page 16 GMK Sphere Calipered Kinematic Alignment Surgical Technique VERIFICATION CHECK TIBIAL RESECTION Measure the thickness of the resected medial and lateral Bring the tibial cutting guide into contact with the tibia by tibial condyles at the base of the tibial spines. This two sliding it along the pins.

  • Page 17: Extension Gap Check

    7. EXTENSION GAP CHECK Test the extension gap with the flexion-extension spacer OPTION (available thicknesses: 10, 11, 12, 13, 14 mm). Use the side As an alternative, modular spacers can be used in order to marked as “EXT”. check the extension gap. The femoral spacer simulates the thickness of the femoral component, while the independent cut reference spacer simulates the thickness of the tibial component plus the minimum 10 mm insert.

  • Page 18: Trial Reduction

    GMK Sphere Calipered Kinematic Alignment Surgical Technique VERIFICATION CHECK If a correction is needed to restore a tight rectangular gap, follow the steps below. At 0°of flexion varus/valgus laxity should be minimized and native knee and limb alignments should be restored. The TIGHT MEDIAL &...

  • Page 19: Balance The Tka With Trial Components

    Place the knee in 90° of flexion. Manually distract the tibia from the femur, apply a posterior drawer test. Confirm the knee is stable. If corrections are needed, refer to the steps in the GMK Sphere - Flex Insert and GMK Sphere - CR Insert decision trees below. CAUTION...
  • Page 20 GMK Sphere Calipered Kinematic Alignment Surgical Technique GMK SPHERE DECISION-TREE - FLEX INSERT GMK SPHERE DECISION-TREE - CR INSERT FLEXION FLEXION Tight Loose Tight Loose Tight Tight 1. If the joint is tight both in extension and flexion recut 1. If the joint is tight both in extension and flexion recut...

  • Page 21: Tibial Bridge Tray

    TIBIAL BRIDGE TRAY Case B: femur size 4 and tibia size 3. In some cases, if different femur and tibia sizes are required, the surgeon should use the trial bridge tray. The trial bridge tray is a baseplate which allows the use of an insert with a different size to the tibia.

  • Page 22: Finishing The Femur And Tibia

    GMK Sphere Calipered Kinematic Alignment Surgical Technique 9. FINISHING THE FEMUR AND TIBIA FEMORAL FINISHING Position the trochlear-milling guide on the distal resection plane using the built-in pegs and insert two pins into the Once trial reduction has been deemed satisfactory, secure fixation holes.

  • Page 23: Femoral Finishing Check

    Option : osteotome Perform the cuts following the sequence shown in the Femoral finishing can be performed with the osteotome by figure to finish the trochlea. using the femoral trochlear-cutting guide.  Femoral peg holes Remove the femoral trial, and prepare the femoral trochlear FEMORAL FINISHING CHECK cutting guide by turning the screw (A) and selecting the size Remove the femoral trochlear milling guide and check the...

  • Page 24: Tibial Finishing

    GMK Sphere Calipered Kinematic Alignment Surgical Technique TIBIAL FINISHING Assemble the reamer guide to the trial tibial baseplate following the marked numbers: • Position the reamer guide on the trial tibial baseplate aligning mark (1) to the centre of the baseplate.

  • Page 25: Tibial Stem Extension

    To remove bone use the reamer clockwise, to Two stem length options are available for primary TKA with compact bone use the reamer counter clockwise (no bone GMK Sphere: 30 mm and 65 mm. is excised). CAUTION In order to avoid the risk of cortical infraction, carefully plan preoperatively the positioning of the stem extension with the help of the X-ray template.
  • Page 26 GMK Sphere Calipered Kinematic Alignment Surgical Technique Ream the canal until the correct depth is reached. For 30 mm stem option For 65 mm stem option ream to the 30 mm mark ream to the 65 mm mark Remove the 11 mm reduction bush and insert the 15.5 mm reduction bush in the reamer guide assembled on the trial baseplate and finish the keel preparation using the15.5 mm...

  • Page 27: Patell A

    10. PATELLA Insert the patella resection guides into the patella clamp. OPTION After carefully releasing the periphery of the patella, The patella size can be assessed using dedicated position the resection guides at the appropriate resection templates. level, with the assistance of the patellar stylus assembled in one slot of the resection guide.

  • Page 28: Selection Of The Prosthetic Components - Size Matching

    GMK Sphere Calipered Kinematic Alignment Surgical Technique 11. SELECTION OF THE PROSTHETIC COMPONENTS - SIZE MATCHING GMK Fixed Tibial Trays can be matched with GMK Sphere Flex/CR Tibial Inserts and GMK Sphere Femoral Components according to Table 1. GMK Sphere Femoral Components...

  • Page 29: Insert

    WARNING When using a GMK Sphere Flex insert, it can be further secured through an optional screw packaged together with it. If the screw option is chosen, the torque limiter screwdriver 3.5 N·m must be used to guarantee that the...

  • Page 30: Annex 1 Unslotted Guide Compatibilit Y

    GMK Sphere Calipered Kinematic Alignment Surgical Technique 13. ANNEX 1 UNSLOTTED GUIDE COMPATIBILIT Y 13.1 DISTAL FEMORAL RESECTION In the table below is highlighted the compatibility between the metal slotted distal cutting guides and the metal unslotted distal cutting guides.

  • Page 31: Annex 2 Mis Guide Compatibilit Y

    14. ANNEX 2 MIS GUIDE COMPATIBILIT Y 14.1 DISTAL FEMORAL RESECTION The compatibility between the metal slotted distal cutting guides and the MIS metal distal cutting guide is highlighted in the table below. Metal slotted distal cutting guide 02.07.10.4574 Metal unslotted MIS Metal slotted MIS distal cutting Metal unslotted MIS distal recut guide 2.642...

  • Page 32: Proximal Tibial Resection

    GMK Sphere Calipered Kinematic Alignment Surgical Technique 14.2 PROXIMAL TIBIAL RESECTION The compatibility between the the metal slotted tibial cutting and the MIS metal distal cutting guide is highlighted in the table below. Metal slotted tibial cutting guide Metal slotted MIS tibial cutting guide 02.07.10.4542/4543...

  • Page 33: Posterior Referencing: Femoral Sizing And External Rotation Adjustment

    15.1 POSTERIOR REFERENCING: FEMORAL SIZING AND EXTERNAL ROTATION ADJUSTMENT Insert an angel wing between the foot of the Posterior Referencing Femoral Sizer posterior to the worn femoral Connect the 0° rotational guide to the Posterior Referenced condyle when compensating for worn cartilage Multisize Femoral Sizer by sliding it onto the driven pins.

  • Page 34: Femoral Upsizing/Downsizing

    GMK Sphere Calipered Kinematic Alignment Surgical Technique Once the position of the sizer is satisfactory, drill the built-in pins holes through the dedicated holes of the femoral sizer (blue circles). CAUTION While drilling, ensure that contact between the femoral sizer and the distal resection is maintained.
  • Page 35 Anterior adjustment (UP +2) Posterior adjustment (UP +2) CAUTION Use the pair of holes marked in the same manner ) for a correct repositioning of the 4in1 cutting block built-in pins. When using the repositioning plate the position of the 4in1 cutting block will be shifted 3.5 mm in mediolateral direction.
  • Page 36 GMK Sphere Calipered Kinematic Alignment Surgical Technique CAUTION Downsizing after femoral resections If, despite soft tissue release, the flexion gap is still tight, a It is strongly recommended not to impact or hammer femoral downsizing may be needed. directly on the 4in1 guide. If the surgeon considers such...

  • Page 37: Impl Ants Nomencl Ature

    16. IMPLANTS NOMENCLATURE GMK SPHERE FEMUR CEMENTED GMK FIXED TIBIAL TRAY CEMENTED REF. LEFT SIZE REF. RIGHT REF. LEFT SIZE REF. RIGHT 02.12.0001L 02.12.0001R 02.07.1201L 02.07.1201R 02.12.0021L 02.12.0021R 02.07.1202L 02.07.1202R 02.12.0002L 02.12.0002R 02.07.1203L 02.07.1203R 02.12.0022L 02.12.0022R 02.12.T3i4L t3-i4 02.12.T3i4R 02.12.0003L 02.12.0003R...
  • Page 38 GMK Sphere Calipered Kinematic Alignment Surgical Technique GMK SPHERE FLEX TIBIAL INSERT - SIZE1 GMK SPHERE FLEX TIBIAL INSERT - SIZE2 THICKNESS THICKNESS REF. LEFT REF. RIGHT REF. LEFT REF. RIGHT (mm) (mm) 02.12.0110FL 02.12.0110FR 02.12.0210FL 02.12.0210FR 02.12.0111FL 02.12.0111FR 02.12.0211FL 02.12.0211FR...
  • Page 39 GMK SPHERE CR TIBIAL INSERT - SIZE1 GMK SPHERE CR TIBIAL INSERT - SIZE2 THICKNESS THICKNESS REF. LEFT REF. RIGHT REF. LEFT REF. RIGHT (mm) (mm) 02.12.0110CRL 02.12.0110CRR 02.12.0210CRL 02.12.0210CRR 02.12.0111CRL 02.12.0111CRR 02.12.0211CRL 02.12.0211CRR 02.12.0112CRL 02.12.0112CRR 02.12.0212CRL 02.12.0212CRR 02.12.0113CRL 02.12.0113CRR 02.12.0213CRL...

  • Page 40: K A Instrument Complement

    GMK Sphere Calipered Kinematic Alignment Surgical Technique 17. K A INSTRUMENT COMPLEMENT Reference Description Q.ty Distal Cut Reference 02.12.10.0721 Block Unworn-Unworn Distal Cut Reference 02.12.10.0722 Block Worn-Unworn Distal Cut Reference 02.12.10.0723 Block Unworn-Worn Distal Cut Reference 02.12.10.0724 Block Worn-Worn 2° Valgus correction 02.12.10.0725...

  • Page 42: Compatibilit Y Chart

    GMK Sphere Calipered Kinematic Alignment Surgical Technique 18. COMPATIBILIT Y CHART GMK Patella GMK Sphere Femur GMK Sphere Flex/CR Insert GMK Tibia Tibia...
  • Page 43 All GMK Resurfacing Patellae can be implanted with all the sizes of GMK Sphere femurs Size 1 Size 2 Size 3 Size 4 Size 5 Size 6 Size 7 Size 1+ Size 2+ Size 4+ Size 5+ Size 6+ Size 3...
  • Page 44 GMK Sphere Calipered Kinematic Alignment Surgical Technique NOTES...
  • Page 46 GMK Sphere Calipered Kinematic Alignment Surgical Technique...
  • Page 47 The instrumentation is not sterile upon delivery. Instruments must be cleaned before use and sterilized in an autoclave respecting the US regulations, directives where applicable, and following the manufactures instructions for use of the autoclave. For detailed instructions please refer to the document “Recommendations for cleaning decontamination and sterilisation of Medacta International orthopaedic devices” available at www.medacta.com.
  • Page 48 Phone +41 91 696 60 60 - Fax +41 91 696 60 66 Kinematic Alignment info@medacta.ch Surgical Technique Find your local dealer at: medacta.com/locations ref: 99.26SPHERE.12MIKAUS rev. 00 All trademarks and registered trademarks are the property of their respective owners.

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