STAR™

Total Ankle Replacement

STA

R A

nkle

Operative Technique

Trauma & Extremities

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This publication sets forth detailedrecommended procedures for usingStryker devices and instruments.It offers guidance that you shouldheed, but, as with any such technicalguide, each surgeon must considerthe particular needs of each patientand make appropriate adjustmentswhen and as required (IFU V5149, V5154, V5160, V5165).

A workshop training is recommendedprior to performing your first surgery.All non-sterile devices must be cleanedand sterilized before use.

Multi-component instruments mustbe disassembled for cleaning. Pleaserefer to the corresponding assembly/disassembly instructions. Pleaseremember that the compatibility ofdifferent product systems have not beentested unless specified otherwise in theproduct labeling.

The surgeon must discussall relevant risks including the finitelifetime of the device with the patientwhen necessary.

STAR

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Contents

Page

Indications/Contraindications 4

1. Operative Technique 8 Step 1 – Setup 8 Step 2 – Axial Plane Alignment 9 Step 3 – Coronal & Sagittal Plane Alignment 10 Step 4 – Tibial Cut 11 Step 5 – Talar Prep & Resection 15 Step 6 – Talar Component Sizing 17 Step 7 – Datum Positioning 19 Step 8 – Talar Circumferential Cuts 20 Step 9 – Implant Sizing and Placement 25

2. Closure and Postoperative Care 31

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Indications / Contraindications

Contraindications:

Active or prior deep infection in the ankle joint or adjacent bones

Skeletal immaturity

Bone stock inadequate to support the device including:

- Severe osteoporotic or osteopenic condition or other conditions resulting in poor bone quality

- Avascular necrosis of the talus

- Prior surgery and / or injury that has adversely affected ankle bone quality

Malalignment or severe deformity of involved or adjacent anatomic structures including:

- Hindfoot or forefoot malalignment precluding plantigrade foot

- Significant malalignment of the knee joint

Insufficient ligament support

Neuromuscular disease resulting in lack of normal muscle function about the affected ankle

Lower extremity vascular insufficiency demonstrated by Doppler arterial pressure

Charcot joint or peripheral neuropathy that may lead to Charcot joint of the affected ankle

Prior arthrodesis at the ankle joint

Poor skin and soft tissue quality about the surgical site

Warnings and Precautions:

Only implant the STAR Ankle after adequate training and familiarity with the surgical technique manual, to avoid increased risk of device failure due to improper surgical technique.

Do not use STAR Ankle components in combination with prosthesis components made by other manufacturers, because design, material or tolerance differences may lead to premature device and/or functional failure. Components of the system have been specifically designed to work together.

To ensure proper implantation of the STAR Ankle, use the instrumentation that is supplied with the system in accordance with the surgical technique manual.

The trial prosthesis should not be implanted.

Examine instruments for wear or damage before use. While rare, intra-operative instrument breakage may occur. Instruments that have experienced excessive use of force may be susceptible to breakage.

The safety and efficacy of the STAR Ankle have not been studied on patients weighing > 250 lbs (113kg).

Always determine that the patient does not have a possible allergy to the implant / prosthesis material before selecting the STAR implant to minimize the risk of an allergic response.

Discard all damaged or mishandled implants. Do not reuse implants and components. Although the implant may appear undamaged, it may have small defects and internal stress patterns which may lead to early failure of the device.

Single use is defined as use of one implant on a single patient in a single surgical procedure.

Reuse of implants designated as single use has been associated with sepsis and/or communication of potentially lethal viruses.

Do not resterilize. Do not use implants or components if the package is damaged or has been opened prior to planned use.

Always exercise care in selecting the proper type and size of the implant. Size and shape of the human bone place restrictions on the size and shape of the implant, potentially limiting device function.

Do not contour or bend an implant because it may reduce its fatigue strength and cause failure under load. Correct handling of the implant is extremely important.

Immediately post-operative through two weeks, a patient should not bear any weight on the implanted STAR Ankle. Certain vigorous activities (e.g., basketball, football) and trauma to the joint replacement may cause early failure of the STAR Ankle. Please refer to the section titled “Closure and Post-Operative Care.”

Appropriate selection, placement and fixation of the STAR Ankle components are critical factors which affect implant service life. Improper selection, placement and fixation of the implant components may result in early implant failure. As in the case of all prosthetic implants, the durability of these components is affected by numerous biologic, biomechanic and other extrinsic factors which limit their service life. Accordingly, strict adherence to the indications, contraindications, precautions and warnings for this product is essential to potentially maximize service life.

Please refer to IFU V5149, V5154, V5160, V5165 for additional labeling information.

INDICATIONS FOR USE

The Scandinavian Total Ankle Replacement (STAR™ Ankle) is intended for use as a non-cemented implant to replace a painful arthritic ankle joint due to osteoarthritis, post-traumatic arthritis or rheumatoid arthritis.

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Preoperative planning can providethe opportunity to review a patient’sanatomy in order to plan appropriateadjustments to the surgical technique.Review of X-Rays can identifyosteophytes, potential deformities, suchas varus/valgus orientation, and otherelements that may eliminate the patientfrom consideration for a STAR, such asgeneralized Avascular Necrosis (AVN)of the talus.

Technique Overview

Implanting the STAR Ankle consistsof a variety of steps intended to ensurepredictable placement and accurate sizingof the implant. A priority is placed onprotecting adjacent anatomical structuresand minimizing bone resection.There are six principle cuts made inorder to prepare the tibia and talus forthe implant. Simple transverse tibial andtalar cuts are made, and after sizing thetalar component, several precise talardome cuts are conducted in order forthe talar dome component to be seatedon top of the talus. The talarcomponent sits on the talus and formsa “Cap” on the top and around all foursides. Holes are drilled in the tibia thatcan serve as anchor points for the tibialcomponent.

Finally, metal components are implanted,and an appropriate polyethylenecomponent is selected, dependingon the laxity of the ankle joint.Concomitant procedures may take placeeither before or after the ankle isreplaced, depending upon the need toprovide soft tissue balancing for theankle. Principle surgical technique stepsinclude:• Orienting the implant in the axialand coronal planes on the tibia• Transverse tibial cut• Orienting the implant on the talus• Talar dome resection• Talar component sizing• Datum positioning• Talar chamfer & medial/lateral cuts• Talar keel preparation• Implant sizing and placementCare has been taken to ensure that theinstrumentation and surgical techniqueenables repeatability and accuracy ofcuts, and provides proper placementand sizing of the implant.

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ComponentsComponents needed to use first in the case:

• First cut – reciprocating saw bladewith teeth up• Jacob’s chuck with anterior millassembled to it• Pin driver with 3.2mm pinassembled to it

Have laid out:

• 3.2mm Pin

• 2.4mm Pins

• Shoulder pin driver equipped

with shoulder pins

• Anterior mill (in jacob’s chuck)

• Barrel hole drill

• Talar keel mill

Other items needed:

• Osteotomes (6mm wide, maximum)

• Angled curette

• Rongeurs

• Army/navy

Pull angel wing, T alignment guide,gear key, #3 (or 6mm) talar cut guide,and appropriate (right or left) tibial cutguide are easily accessible.

Post talar cut sizing template (PTCT)ensure PTCT drill guide can bescrewed onto smallest sizer, withoutcross threading, and no gap betweencomponents (handle of sizer not bent).

Back Table LayoutAssemble together:

• Lateral tibial alignment guide

• Lateral tibial alignment rod

Assemble together:

• Tibial alignment guide

• Tibial alignment guide thumbscrew

Then assemble the above with:

• Pin block assembly (lightly lock thumbscrew on rod from assembly)

Use gear key to loosen set screw on pin block assembly, and then assemble:

• Adjustable Slider Block (leave halfway out from Pin Block Assembly,at thicker marked line)

Tighten down set screw on pin blockassembly.

Ensure rounded corners are up ondistal portion of Adjustable slider block.Ensure ‘funnel’ side of the tibialalignment guide lock is down.

Preoperative Planning

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Preoperative Planning

ApproachA small bump is placed beneath theipsilateral hip to rotate the ankle sothat the line of the medial malleolusis perpendicular to the operating table.After the foot and ankle have beencorrectly positioned, the leg is elevatedfor about 2 minutes, and a thigh hightourniquet is inflated with an appropriateamount of pressure for the size of thepatient’s leg and foot. The leg should beprepped and draped above the knee toallow the placement of the 3.2mm TibialPin.

A longitudinal 20cm incision is centeredover the ankle immediately lateral tothe anterior tibial tendon. The incisionis deepened to the ankle joint whileretracting the extensor hallucis longusand the neurovascular bundle laterally.

The superficial branch of the peronealnerve in the foot is visible and must beretracted carefully to the lateral aspectof the ankle.

It is frequently necessary to sacrificeone small branch of this nerve thatinnervates the great toe. The tendonsheath of the extensor hallucis longusis now incised in line with the skinincision. Every effort is made to avoidopening the tendon sheath of theanterior tibial tendon, since this maycause difficulty in closure. After thetendon sheath of the extensor hallucislongus is opened, the deep peronealnerve and artery are identified and aregently retracted. The ankle capsulartissues are incised in line with theskin incision and then are elevated

and mobilized exposing the medialmalleolus, and lateral malleoli.

If the capsule is of sufficient quality,it should be saved to close overthe prosthesis. It is important toavoid the release of the anteriortalofibular ligament as this may leadto lateral instability. The ankle joint isdistracted slightly, and hypertrophicsynovium, intraarticular loose bodiesor periarticular spurs are resected.Osteophytes on the anterior distaltibia are removed to visualize the tibialplafond.

Note:Self-retaining retractors should beavoided when possible, to eliminateexcess pressure on the skin edges.Hand retractors should be frequentlyrepositioned to minimize the risk oftissue trauma.

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Operative Technique

Step 1Setup

1.1 Make a mark at the level of thetibial tubercle. Place an osteotomein the medial gutter. Create a stabincision over the mark. Insert a3.2mm self-drilling pin intothe tibial tubercle, parallel to theosteotome in the gutter in the axialplane, but in slight plantarflexion.

1.2 Position the proximal portion ofthe previously assembled TibialAlignment Guide over the pin,at a height of one fingerbreadthabove the tibia proximal to theknee (if measuring distal tothe knee, use two fingerbreadths),and tighten the proximal screwto lock the guide superiorly.

Adjusting the pin block

1.3 The gear key is used to both lockinto position, and adjust the pinblock. The diagram illustrateswhich holes manipulate eachof the components.

1.4 Extend the pin block assemblyto allow for a one-centimeter gapbetween the proximal and distalblocks.

1.5 Adjust the distal aspect of thetibial alignment guide (roughlyat the level or above the plafond)proximal to the tibial plafondto allow for a cut just proximal to the articular surface.

Locking ScrewAdjustment Gear

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Operative Technique

1.6 Generally align the Tibial AlignmentGuide over the crest of the tibia.

1.7 Hand tighten the proximal andmiddle screws of the tibial alignmentguide.

Step 2Axial Plane Alignment

2.1 Place an Osteotome in the medialgutter. Place the “T” AlignmentGuide over the distal end of theAdjustable Slider Block.

2.2 Release the middle thumb screw onthe tibial alignment guide and adjustthe rotation to ensure the shaft ofthe “T” Alignment Guide is parallelwith the osteotome.

2.3 Put one pin in the superior PinBlock Assembly, only penetratingthe first cortex of the tibia to allowvarus/valgus and tibial cut slopeadjustment. This locks the axial plane alignment.

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Operative Technique

2.4 Remove the “T” Alignment Guideand osteotome.

Step 3

Coronal & Sagittal Plane Alignment

3.1 Adjust the coronal plane alignmentby loosening, and rotating the guidemedially or laterally on the 3.2mmtibial tubercle pin. Hand tightenthe set screw after final positioning.

3.2 Attach the Parallel Alignment Guideto the mid-portion of the TibialAlignment Guide.

3.3 Align the tibial alignment guide tobe parallel to the tibial diaphysis inboth the coronal and sagittal planes.Confirm with fluoroscopy.

Alignment can be adjusted bychanging the position of the TibialAlignment Guide with respect to thepins in place. For example, raisingthe proximal portion of the TibialAlignment Guide on the 3.2mm pinwill close the anterior angle of thetibial cut in the sagittal plane.

Note: When the Tibial Alignment Guideis parallel from a lateral view to theintramedullary canal, the tibial cutangle is 3° open anterior, with thetypical anatomic patient being7°-10° open anterior.

Notes

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3.4 Drive the initial pin that was earlierplaced in the Pin Block Assembly tothe far cortex to lock the slope of thecut in the sagittal plane.

3.5 Remove the Parallel Alignment Guide.

Step 4

Tibial Cut

4.1 Attach the Tibial Cut Guide onto theAdjustable Slider Block and secure itin place with the Gear Key.

4.2 Insert the Angel Wing into thecutting slot of the Tibial Cut Guide.The Angel Wing has seven pegsextending five millimeters superiorand inferior from the central blade.

The Pegs are spaced 10mm apart, so canbe used to generally determine the depthof the cut from an A/P perspective.

Operative Technique Notes

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Operative Technique

4.3 The Angel Wing design accounts forthe amount of bone resected by thesaw blade, when measuring the cut.

4.4 Use the Gear Key on the set screwand adjustment within the Pin BlockAssembly to loosen and align theAdjustable Slider Block such thatthe inferior tip of the closest peg isaligned with the most superior aspectof the distal tibial plafond. With thisdefault setting, a maximum of fivemillimeters of distal tibial bone willbe removed.

Fluoroscopy is properly positionedwhen the lateral view of the widesection of the wing is a thin singleline also known as a “True LateralView.”

Note:The Angel Wing mimics thethickness of the saw blade. Doublecheck the “Slope” of the tibial cut inthe sagittal plane. Make additionaladjustments as needed. The defaultsetting of the cut guides is to provide3° open slope.

4.5 Tighten the set screw to lockthe resection level of the TibialAlignment Guide. Now secure theguide in the oblique holes usingthe 2.4mm pins.

5mm

5mm5mm

5mm

Blade/Wing

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Operative Technique

4.6 Remove the Angel Wing.

4.7 Make medial and lateral adjustmentswith the gear key to minimize therisk of notching either the medialand lateral malleoli during tibialresection.

4.8 Insert two 2.4mm pins into theinferior portion of the Pin BlockAssembly to lock the amount oftibial resection.

Note:Use the holes marked “0” (the mostproximal). This will enable a 2mmadjustment if a recut is needed simplyby repositioning the Adjustable sliderBlock from the “0” holes to the “2”holes.

4.9 Insert medial and lateral pinsinto their slots in the saw guide toprotect the medial malleolus andfibula from notching or cutting.

Note:Ensure the pins are seated deeplyenough to avoid interfering withthe saw in order to properly conductthe tibial cuts.

5mmTargetPinLocation

Tibia

Locks Medial/ Lateral Adjustments

Notes

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Operative Technique

4.10 With the oscillating saw, usinga pecking motion to determineproper depth, make a transversedistal tibial cut within the TibialCut Guide.

4.11 With the reciprocating saw, makean upward, proximally-oriented cutwith a pecking motion along theinner edge of the medial malleolus.Care should be taken to not overcutthe tibial bone.

4.12 Remove the pins from the TibialCut Guide, unlock it from the PinBlock Assembly and remove theTibial Cut Guide.

4.13 Using osteotomes, rongeurs,or other surgical instruments,remove all resected tibia bone.

Notes

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Step 5Talar Prep & ResectionNote:

For patients with deformities, it maybe appropriate to mobilize the talus bycleaning out both lateral and medialgutters.

5.1 Insert the Number 3 (or 6mm) TalarCut Guide onto the Tibial AlignmentGuide, and lock in place by tighteningwith the set screw. With the Talar CutGuide in this position, a maximum of4mm of bone will be removed fromthe talar dome.

5.2 The Talus should be NeutrallyPositioned (90o perpendicular) tothe long axis of the tibia. Excessivedorsiflexion will rotate the talarcomponent anteriorly while excessiveplanterflexion will rotate it posteriorly.Proper orientation protects the talarneck from inadvertent weakeningfrom the anterior chamfer cut.

5.3 The talus must be touching thepaddle face for an adequate amountof resection. The foot should be in aneutral or slightly valgus orientation.

5.4 Insert the Angel Wing to verifythe orientation and angle of the talarcut and amount of the resection.

5.5 Insert medial and lateral fixationpins into the Talar Cut Guidewhile holding the foot in a neutralalignment.

Operative Technique Notes

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Operative Technique Notes

5.6 Insert medial and lateral pins intothe talar cutting slots to protect themalleoli.

Note:Ensure the pins are properly aligned,and use a mallet to begin placement ofthe pins to ensure proper orientationand alignment. Improper alignmentmay cause the pins to bind in the holesof the Talar Cut Guide.

5.7 Using the oscillating saw, make thetransverse distal talar cut.

5.8 Remove the pins from the Talar CutGuide, unlock it from the Pin BlockAssembly and remove the Number 3(6mm) Talar Cut Guide.

5.9 Insert the 12mm end of the JointSpace Evaluator between the cutsurfaces of the tibia and talus. 12mmof space is required for positioning ofthe tibial and talar components witha 6mm bearing.

If the Joint Space Evaluator does notfit easily in the joint space, additionalbone will have to be cut, at the surgeon’s discretion. This will typically be done on the tibia. Additional tibialbone can be removed by re-attachingthe Tibial Cut Guide to the Adjustable Slider Block.

5.10 Remove the Tibial AlignmentGuide and corresponding 2.4mmpins.

Note:If the talar dome is unevenly cut,it may be necessary to flatten thesurface of the talus in order toproperly use the Post Talar CutTemplate (PTCT) to size the talarcomponent.

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Operative Technique

Step 6Talar Component Sizing

6.1 Insert the Post Talar Cut Template(PTCT) onto the cut surface ofthe talus. The template determinesthe correct talar component size.The outer outline of the templatecorresponds to the outer outlineof the talar component. For optimal sizing, the outer surfaceof the PTCT should match theouter edge of the talar bone.

Note:One side of the Post Talar CutTemplate is for the left ankle,and the other is for the right ankle.

Size A (mm) B (mm)

XXSmall 28 29XSmall 30 31Small 34 35Medium 36 35Large 38 35

6.2 Once the appropriate PTCT isdetermined, attach the drill guideonto the PTCT.

6.3 Rotational alignment of the sizeris determined by aligning the shaft of the PTCT toward the second metatarsal. Note the size on the Post Talar Cut Template. The size of the datum used in future steps will conform to the appropriate size of the PTCT. Approximately center the PTCT on the surface of the talus.

Too large and will cause overlapin the gutters.

Too small and will cause too muchbone to be removed.

A

B

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Operative Technique

6.4 The post of the drill guide shouldbe centered over the lateral process.Anterior/Posterior positioning ofthe template is achieved by usingthe c-arm to align the midpoint ofthe template to the center of rotationof the talus.

Note:Use the Joint Space Distractor toclamp the PTCT to the top of the talus; pay particular attention that there is no gap between the PCTC and the top of the talus especially posteriorly.

6.5 Once template alignment is properlypositioned, insert a 2.4mm pinthrough the drill guide.

6.6 Loosen the thumbscrew on thePTCT Drill Guide and remove.Separately, remove the PTCT,leaving the pin in the talus.

Notes

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Operative Technique

Step 7Datum Positioning

X-Small and XX-Small sizes skip Step 7.Datum is integrated into the A/Pand M/L cut guides.

7.1 Select a Datum that matches the sizeof the previously determined PTCTonto the Datum Holder. Slide theDatum mounted on its holderover the 2.4mm pin in the talus.Align the handle of the Datum Holder with the 2nd metatarsal.

7.2 Secure the Datum to the talus with15mm Drill Tip Pins (w/shoulder)using the Pin Driver. Should thisprovide insufficient purchase,20mm length pins are also availablefrom the sterile Instrument set.If power is used with the Pin Driver,care should be taken to ensure finaltightening is done manually.

Note:If inserting under power always finish tightening manually.

7.3 Remove the 2.4mm Pin and then the Datum Holder.

7.4 Insert the Talar A/P Cut Guide ontothe Datum and secure it with itslocking bolt.

Notes

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Operative Technique

Step 8Talar Circumferential Cuts

XS/XXS - Talar A/P Cut Guide is placed over the centering 2.4mm pin, and secured to the Talus with the shoulder pins.

8.1 Place a 2.4mm drill pin in thedistal section of the A/P Cut Guideto secure it, being careful not topenetrate into the subtalar joint.

8.2 With an oscillating saw, makethe posterior talar cut throughthe posterior guide of the TalarA/P Cut Guide.

8.3 Beginning with the distal cut slot,and proceeding with the proximalcut slot, prepare the anterior surfaceof the talus through the superiorand inferior slots of the Talar A/PCut Guide with a pecking andsweeping motion.

Notes

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Operative Technique

8.4 Remove the pin from the TalarA/P Cut Guide, unlock it from theDatum, and remove the Talar A/PCut Guide from the Datum.Make sure all loose bone is removedfrom the anterior surface of the talus,and the surface is smooth so as to notinterfere with Talar M/L Cut Guidein the next steps.

XS/XXS - Place a 2.4mm Drill Pin back into the center hole of the guide. Remove the two shoulder bolts. Remove the A/P Cut Guide. Insert the Talar M/L Cut Guide onto the centering 2.4mm pin and secure it with the two shoulder pins.

8.5 Insert the Talar medial/lateral CutGuide onto the Datum. Secure itwith its locking bolt.

8.6 The reciprocating blade is insertedinto the guide until the laser markand last cutting tooth are flushwith the front edge of the guide.The saw is then started and rotatedby dropping the tip of the saw bladeuntil the top edge of the blade iseven with the engraved line onthe side of the guide. This insuresthe proper depth of resection whileavoiding resecting down into thesub-talar joint.

8.7 The blade is then drawn anteriorlyuntil the teeth meet the bottom edgeof the anterior chamfer face.

Note:For additional fixation support,with osteopenic bone, for example,additional pins or shoulder pins canbe utilized in the Talar M/L Cut Guide.

Use the Joint Space Distractor toclamp the M/L Cut Guide to the topof the talus; pay particular attentionthat there is no gap between the M/LCut Guide and the top of the talusespecially posteriorly.

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8.8 The same motion is repeatedon the other side.

8.9 Remove the Talar M/L Cut Guide,Datum, and fixation pins from thetalus. Take care to fully engage thePin Driver on the Drill Tip Pins byrotating the Driver until the squareend of the Pin seats deeply inside thePin Driver. If using power, ensure fullengagement before applying power.

Note:The M/L talar cut bone is most easilyremoved by using a 6mm osteotomeat 90° to the cut surface, rather thanprying the bone away from the centerof the talus.

8.10 Using an osteotome, remove themedial/lateral cut section of thetalus. Approximately 10mm medialand 15mm lateral gutter bone mustbe removed.

8.11 Using forceps, place the TalarWindow Trial over the talus.The Talar Window Trial is usedto ensure that all talar cuts arecomplete and accurate, and allloose bone has been removed.

8.12 Secure the Talar Window Trialwith two 2.4mm fixation pins.

Note:

Ensure the pins are properly aligned, and use a mallet to begin placement of the pins to ensure proper orientation and alignment. Improper alignment may cause the pins to bind in the holes of the Talar Window Trial.

Operative Technique Notes

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NotesOperative Technique

8.13 Insert the Talar Keel Mill into thecenter slot of the Talar WindowTrial, and drill an anterior hole,a posterior hole, and center hole.Connect the holes by sweeping thedrill in the slot.

Note:

Raise the drill as close to the tibia as possible, then pull the mill forwards; this will ensure that an anterior window is created in the anterior cut surface of the talus.

8.14 Remove the Talar Keel Mill, fixation pins, and Talar WindowTrial.

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Operative Technique

8.15 Insert the Keel Broach intokeel slot to check the talar cuts.

8.16 The back angled surface of thekeel broach should line up withthe posterior talar cut, and thevertical face should line up withthe intersection of the anteriorand superior talar cuts.

Notes

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Operative Technique

Step 9Implant Sizing and Placement

9.1 To obtain the correct size for thetibial component, hook the edge ofthe ruler to the posterior edge of thetibial surface.

9.2 Obtain anterior/posterior dimensionmedially and laterally on the tibia,and select corresponding tibialcomponent based on the referencechart below.

9.3 Insert corresponding Barrel HoleGuide (BHG) to confirm adequatespace. The black etch on the inferiorportion of the Barrel Hold Guidemimics the actual implant’s. Depthand tibial surface coverage can beconfirmed on fluoroscopy.

Note:Note how deeply inserted the BHGis – the tibial component will beimplanted as deeply as the flange ofthe BHG is positioned in relation tothe tibia.

Note:Gapping, due to bone fragments canalso be identified with fluoroscopy.Look for incongruence or gapsbetween the Barrel Hole Guideand the cut surface of the Tibia.

Size A (mm) B (mm)

X-Small 30 30Small 32 30Medium 32.5 35Large 33 40X-Large 33.5 45

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Operative Technique

9.4 Insert the talar component ontothe prepared talus. The notched endof the Joint Space Evaluator can beused on the anterior edge of the talarcomponent to aid in impacting thetalar component in place. Seat the talarcomponent with the talar impactor.

9.5 Use the Joint Space Evaluator 9mmend to ensure the talar componentis properly seated. Fluoroscopy canbe used to determine proper A/Ppositioning of the talar component.

9.6 Next, insert the Trial Poly betweenthe tibia and the talar component.The poly ensures that the Barrel HoleGuide (BHG) is flush against theprepared tibial surface and to protectthe bearing surface while inserting.

Note:The Tibial Component should havemaximum cortical coverage to resistsubsidence. A small amount ofoverhang anteriorly and posteriorlyis acceptable.

9.7 Place the BHG against the preparedsurface of the tibial cut. Ensurealignment of the BHG with the talarcomponent. Fluoroscopy shouldbe used to ensure the BHG is flushwith the cut tibial surface. If gappingoccurs, it is possible that additionalbone fragments are present, and needto be removed. Secure the BHG to thetibia with two 2.4mm fixation pins.

Notes

27

Operative Technique

9.8 Drill the first hole with a 6.5mmBarrel Hole Drill with hand slightlydropped toward the foot to preventthe drill from skiving downwardposteriorly. Ensure the hole is drilledall the way so that the positive stopon the drill meets the Barrel HoleGuide.

9.9 Remove the drill bit, and insert theBarrel Hole Plug in the drilled holeto ensure precise spacing as the secondhole is drilled. Drill the second hole,being sure to drill all the way to thepositive stop on the drill.

9.10 Use the Key Hole Broach to removethe thin section of bone betweenthe hole and the cut tibial surface.Then, the Barrel Hole Plug should beinserted in the second hole, and thefirst hole should be prepared withthe Key Hole Broach.

9.11 Remove the fixation pins and BHG,leaving the proximal pin to guideorientation during impaction.

9.12 Select a tibial component thatmatches the size of the BHG.Mount the tibial component ontothe tibial inserter, locking it withthe thumb screw.

Notes

28

Operative Technique

9.13 Insert the mounted tibial component into the prepared tibial barrel holes, ensuring alignment with proximal pin.

Note:Drop hands toward foot while impacting to ensure barrels remain seated in prepared channels. Place the foot in maximum plantarflexion.

Impact the tibial component until the barrels are fully inserted in the tibia.

Note:Due to the slope of the bone of theanterior tibia, the tibial tray mayprotrude 1mm from the currentanterior edge of the anterior tibia.However, due to the poor soft issueenvelope of the ankle, too muchprotrusion is to be avoided.

9.14 Loosen the thumbscrew on thetibial inserter, and remove theTibial Inserter. Fluoroscopy can beused to determine proper implantdepth. Use the notched side of theJoint Spacer Evaluator to impactthe tibial component to its finaldepth. Place the smallest TrialBearing between the tibial andtalar components.

Note:A 2.4mm pin can be used to loosen the thumbscrew on the Tibial Inserter in case it is put on too tightly.

9.15 To assess bearing size, place thetrial bearing in the joint space.If the trial forceps is used,be careful not to scratch thepolished bearing surfaces, anddo not twist the forceps to assessvarus/valgus, as this can stressthe forceps metal tips.

Notes

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Operative Technique

9.16 Once the trial bearing is in place,assess the ankle stability and assessthe Trial Bearing size.

9.17 If a gap of more than a millimeteris seen anywhere between the trialbearing and metal components,try the next thicker size. If a gapoccurs only on one side, ligamentbalancing may be necessary.

9.18 If satisfactory results are obtained,replace the trial bearing with theappropriate final mobile bearing.

Note:If the trial bearing is difficult toremove, plantarflex the foot to movethe bearing anteriorly and shuckthe heel to better release the trial.

9.19 Fill the two barrel holes with bonegraft and tamp to compact thematerial.

9.20 Perform any adjunct procedures,and then close the incision in layers.

Notes

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Operative Technique

Closure and Postoperative CareFor a minimum of two weeks after surgery, the patient should limit weight bearing on the operated ankle. The patient should keep ‘toes above the nose’ as much as possible while limiting all physical activities. Partial weight-bearing may begin at 2 to 3-weeks post-operative and gradually increase until the patient is fully weight-bearing at 4 to 6-weeks post-operative.

Implant RemovalThe polyethylene component can typically be removed with towel clamp to grip the sides. For tight joints, should polyethylene replacement be required, this component can also be drilled into, taking care to not damage any of the metal components. After drilling with a small drill, the shoulder pins can be used to lock into the polyethylene and remove the component.

Tibial Component Removal

A Tibial Component Remover is included in the system. The Tibial plastic end of the Barrel Impactor can be removed (by unscrewing the large knob), and replaced with the Tibial Extractor. The Tibial Extractor can be inserted into the joint space and the distal lip hooke over the posterior of the Tibial component. Be sure to remove bones covering the anterior aspect of the barrels. A thin, flexible osteotome may be required to free the implant from the bone.

Talar Component Removal

An osteotome can be used to disengage the Talar Component from the talus. For a well fixed Talar Component, an osteotome can be used to carefully separate the Talar Component from bone.

This document is intended solely for the use of healthcare professionals. A surgeon must always rely on his or her own professional clinical judgment when deciding whether to use a particular product when treating a particular patient. Stryker does not dispense medical advice and recommends that surgeons be trained in the use of any particular product before using it in surgery.

The information presented is intended to demonstrate a Stryker product. A surgeon must always refer to the package insert, product label and/or instructions for use, including the instructions for Cleaning and Sterilization (if applicable), before using any Stryker product. Products may not be available in all markets because product availability is subject to the regulatory and/or medical practices in individual markets. Please contact your Stryker representative if you have questions about the availability of Stryker products in your area.

Stryker Corporation or its divisions or other corporate affiliated entities own, use or have applied for the following trademarks or service marks: STAR, Stryker. All other trademarks are trademarks of their respective owners or holders.

The products listed above are CE marked.

Content ID: STAR-ST-2 Rev 1, 09-2015Copyright © 2015 Stryker

Manufactured by:

Stryker GmbHBohnackerweg 1 2545 SelzachSwitzerland

www.stryker.com

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