femoral stem surgical techniquefemoral neck. use a one-piece box osteotome (fig. 5) to remove this...

FEMORAL STEM SURGICAL TECHNIQUE

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FEMORAL STEM

DEVICE INDICATIONS FOR USEThe ICONACY I-Hip total hip replacement is indicated for the following conditions:

1. A severely painful and/or disabled hip joint as a result of osteoarthritis, traumatic arthritis, rheumatoid arthritis, or congenital hip dysplasia.

2. Avascular necrosis of the femoral head.3. Acute traumatic fracture of the femoral head or neck.4. Failedprevioushipsurgeryincludingjointreconstruction,internalfixation,arthrodesis,hemiarthroplasty,

surface replacement arthroplasty, or total hip replacement.5. Certain cases of ankylosis.6. Nonunions,correctionoffunctionaldeformity,andtrochantericfracturesoftheproximalfemurwithhead

involvement that are unmanageable using other techniques

The ICONACY I-Hip system consists of femoral stem and acetabular cup (i.e., shell) porous coated components intendedforcementless,press-fitfixation.

Refer to the Package Insert for the list of contraindications.

Standard and Lateral Femoral Stem Sizes

8 9 10 11 12 13 14 15 16

Fem

oral

H

ead

Size

s 28mm

32mm

36mmThis device is only available for commercial distribution in the United States.

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GENERAL DESCRIPTION OF IMPLANTThe ICONACY I-Hip Femoral Stem System consists of a collarless, tapered, titanium alloy femoral stem mated to a Co-Cr alloy modular femoral head (Fig. 1). The I-Hip Femoral Stem System articulates with the acetabular device assembly in the ICONACY I-Hip Acetabular Cup System.

The I-Hip Femoral Stem Implant (i.e., stem) is made of forged Ti-6Al-4V ELI alloy. The stem is a double taper design. When viewed in the in situ position, the stem hasaslightsymmetricaltaper,proximaltodistal,inthe sagittal plane, and a basically symmetrical taper, proximaltodistal,inthecoronalplane,endinginaroundedtip.Theproximallateraledgeiscurved,ratherthan straight, to allow the stem to clear the bony base of the greater trochanter of the femur during insertion.

Theproximal40%ofthestembodyiscircumferentiallyporous coated with titanium plasma spray to attain cementless,press-fitfixation.Thedistal60%ofthestembodyhasasmooth,satinfinish.

Stemlengthsvarywithstemsize,rangingfrom110mmto 145mm. The stem sizes, measured at the stem width inthecoronalplaneatapointapproximately90mmdistalfromthestemproximalshoulder,rangefrom 8mm to 16mm, resulting in nine stem sizes (Table 1).

The stems are available in two varieties of femoral necks, a standard and a lateral (Fig. 2). The lateral design providesanadditional6mmoflateralizedoffsetforthefemoral heads. The stem necks have a standard 12/14 taper to accommodate the socket of the associated modular femoral heads.

The femoral heads are manufactured from wrought Co-Cr alloy and are available in 3 head diameters: 28mm, 32mm,36mm.Theheadsareavailableinfivecommonnecklengths:-4mm,+0mm,+4mm,+8mm,and+12mm(Table 2). The femoral heads can be used on any I-Hip femoral stem for any of the associated neck length options.

Thefemoralheadshaveacolorbufffinishtominimizewear,withasurfacefinishof0.05μmMaxRa. The heads have a 12/14 taper socket to mate with the taper of the femoral stems.

Neck Length Options

-4mm +0mm +4mm +8mm +12mm

Fem

oral

H

ead

Size

s 28mm

32mm

36mm

Standard and Lateral Femoral Stem Sizes

8 9 10 11 12 13 14 15 16

Fem

oral

H

ead

Size

s 28mm

32mm

36mm

Table 2 – Femoral head neck length options guide. Table 1 – Femoral stem and femoral head sizing guide.

Figure 1 – I-Hip Femoral Stem System.

Figure 2 – Standard and lateral femoral stem necks.

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FEMORAL STEM

PREOPERATIVE PLANNINGEffectivepreoperativeplanningallowsthesurgeontopredicttheimpactofdifferentinterventionsinordertoperform the joint restoration in the most accurate and safemanner.Optimalfemoralstemfit,thelevelofthefemoral neck cut, the prosthetic neck length, and the femoralcomponentoffsetcanbeevaluatedthroughpreoperative radiographic analysis. Preoperative planning also allows the surgeon to have the appropriate implants available at surgery.

The important parameters of preoperative planning include:

• Determinationofleglength• Establishmentofappropriateabductormuscle

tensionandfemoraloffset• Determinationoftheanticipatedcomponentsize

The overall objective of preoperative planning is to enable the surgeon to gather anatomic parameters which will allow accurate intraoperative placement of the femoral implant.

Determination of Leg Length

Determiningthepreoperativeleglengthisessentialforrestoration of the appropriate leg length during surgery. Ifthereareconcernsregardinglowerextremityorlumbarabnormalities,suchasequinusofthefoot,flexionor varus/valgus deformities of the knee, or scoliosis, perform further radiographic evaluation to aid in the determination of preoperative leg length status.

An anterior/posterior (A/P) pelvic radiograph often gives enough documentation of leg length inequality to proceed with surgery. If more information is needed, a scanogram or CT evaluation of leg length may be helpful. From the clinical and radiographic information on leg lengths, determine the appropriate correction, if any, to be achieved during surgery.

Ifthelimbistobesignificantlyshortened,osteotomyand advancement of the greater trochanter or a subtrochanteric shortening osteotomy may be necessary. If the limb is shortened without osteotomy and advancement of the greater trochanter, the abductorswillbelaxpostoperatively,andtheriskofdislocation will be high. Also, gait will be compromised bythelaxityoftheabductors.Ifleglengthistobemaintained or increased, it is usually possible to perform the operation successfully without osteotomy of the greater trochanter. However, if there is some major anatomic abnormality, osteotomy of the greater trochanter may be helpful.

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Establishment of Appropriate Abductor Muscle Tension and Femoral Offset

Once the requirements for establishing the desired postoperativeleglengthhavebeendecided,thenextstep is to consider the requirement for abductor muscle tension. When templating, center the femoral component inthecanal.Choosetheoffset(i.e.,StandardorLateral)thatmostcloselyapproximatesthatofthepatientwhenthe new center of rotation is determined (after acetabular component templating). For patients with a very large distance between the center of rotation of the femoral head and the line that is centered in the medullary canal, insertionofafemoralcomponentwithalesseroffsetwillmedializethefemoralshaft.Totheextentthatthisoccurs,laxityintheabductorswillresultwith a heightened dislocation risk.

Althoughrare,itmaynotbepossibletorestoreoffsetinpatientswithanunusuallylargepreoperativeoffsetor with a severe varus deformity. In such cases, tension in the abductors can be increased by lengthening the limb, a method that is especially useful when the involved hip is short. If this option is not advisable and if the disparity is great between the preoperative offsetandtheoffsetachievedatsurgerybyusingthelongest head/neck piece possible, some surgeons may choose to osteotomize and advance the greater trochanter to eliminate the slack in the abductor muscles. Technical variations in the placement of the acetabular componentscanalsoreducethedifferencesinoffset.

Determination of the Anticipated Component Size

Preoperative planning for insertion of a cementless femoral component requires at least two radiographic views of the involved femur: an A/P view of the pelvis centered at the pubic symphysis, and a frog leg lateral viewonan11x17-inchcassette.Bothviewsshouldshowatleast8inchesoftheproximalfemur.Inaddition,it may be helpful to obtain an A/P view of the involved side with the femur internally rotated. This compensates for naturally occurring femoral anteversion and provides a more accurate representation of the true medial-to-lateral dimension of the metaphysis. When templating, magnificationofthefemurwillvarydependingonthedistancefromthex-raysourcetothefilm,andthedistancefromthepatienttothefilm.Magnificationmarkerscanbeusedtoidentifytheactualmagnificationof the radiograph. Knowing this will help to more accurately predict the component size when templating.

6

FEMORAL STEM

TEMPLATING THE FEMORAL STEMThe objectives in templating the stem include determining the anticipated size of the implant to be inserted and the location of the femoral neck osteotomy.

To estimate the femoral implant size, assess the body size on the A/P radiograph. Superimpose the template (Fig.3) on the metaphysis and estimate the appropriate sizeofthestem.Thebodyofthestemshouldfit,ornearlyfit,themedial-lateraldimensionsofthemedullarycanalontheA/Px-rayfilm,andshouldnot be superimposed onto cortical bone.

After establishing the proper size of the stem, determine theheightofitspositionintheproximalfemurandtheamountofoffsetneededtoprovideadequateabductormuscletension.Generally,iftheleglengthandoffsetare to remain unchanged, the center of the head of the prosthesis should be at the same level as the center of the femoral head of the patient’s hip. This should also correspond to the center of rotation of the templated acetabulum. To lengthen the limb, raise the template proximally.Toshortenthelimb,shiftthetemplatedistally.Thelateraloffsetoptionofferslateraltranslationof6mm.Thisallowsforanoffsetincreaseof6mmwithoutchanging the vertical height or leg length. The femoral headnecklengthwillalsoaffectleglengthandoffset.

Once the height has been determined, note the distance in millimeters from the underside of the osteotomy line to the top of the lesser trochanter by using the millimeter scaleonthetemplate.Forexample,onemightdecidefromthetemplatingthata52mmO.D.cup,withasize 15 femoral stem and a 28mm femoral head, placed 15mm above the lesser trochanter, are the appropriate choices.Proximal/distaladjustmentsinprosthesisposition reduce the need for a femoral head with a skirt.

Figure 3 – Femoral stem template.

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PREPARATION OF THE FEMURItiscrucialtoadequatelyvisualizetheproximalfemur so the correct insertion site for the femoral instruments can be located. Refer to the preoperative planning at this point.

The level of neck resection is determined during preoperativetemplating.Althoughspecifictoeachpatient,theneckcutoftenwillbeapproximately1cmabove the lesser trochanter. Center the appropriate FemoralResectionGuidealongtheneutralaxisofthefemur and mark the resection line (Fig. 4). Perform the neck osteotomy, taking care to maintain the desired angle.

Identifythemid-femoralshaftextensionintraoperativelyas viewed on the A/P and lateral radiographs. This is usually in the area of the piriformis tendon insertion in the junction between the medial trochanter and lateral femoralneck.UseaOne-PieceBoxOsteotome(Fig. 5) to remove this medial portion of the greater trochanter and lateral femoral neck.

The opening must be large enough for the passage of each sequential rasp to help ensure neutral rasp/implant alignment.Aninsufficientopeningmayresultinvarusstem positioning. Use the Rat-Tailed Rasp to remove additional bone from the base of the greater trochanter and to help avoid varus stem positioning (Fig. 6).

After removing the cortical bone, use the smallest Femoral Stem Rasp to open the medullary canal. This will provide a reference for the direction of the subsequent femoral rasping.

Figure 6 – Rasp to remove bone from greater trochanter.

Figure 5 – One-piece box osteotome procedure.

Figure 4 – Use femoral resection guide to mark neck resection.

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FEMORAL STEM

FEMORAL RASPINGBegintheraspingsequencewithaFemoralStemRasp (Fig. 7) that is at least two sizes smaller than the estimated implant size. Advance in 1 or 2 size incrementsuntilthedesiredfitandstabilityisachieved.When inserting the rasp, be sure that it advances with each strike of the mallet. If the rasp can be seated at least5mmbelowtheosteotomy,progresstothenextraspsizeandrepeatuntilthepredictedfinalraspsizehas been seated.

NOTE:Beforeusingthenextsizerasp,besurethattheopening is large enough. If it is not, use the one-piece boxosteotomeorpreviousraspagain.Theopeningshouldnotbesignificantlylargerthantherasporimplant.

Ifthepredictedfinalraspsizecanbecountersunkmorethan 5mm and adequate cancellous bone is available in the metaphysis region (including the medial calcar), progresstothenextlargerraspsizeafterensuringthatthereissufficientroominthedistalmedullarycanal.

The rasps and corresponding implants are sized such thatapress-fitiscreatedproximally.Theplasmasprayed surface of the implant is slightly proud as compared to the surface. Thus, the implant is more than 1mm larger than the rasp in both the A/P and M/L dimensions. This relationship can be seen on the templates.

NOTE:Themetaphysealpress-fitengagementprovides the implant with greater rotational stability than the rasp.

CALCAR PLANING (OPTIONAL)Ifdesired,afterthefinalrasphasbeeninsertedtotheproper level, use the Calcar Planer to plane the femoral neck. Insert the trunnion post of the rasp into the hole on the bottom of the Calcar Planer (Fig. 8). Start the drill/driver and advance the planer into the bone slowly until the appropriate neck area has been planed.

Figure 7 – Femoral stem rasp procedure.

Figure 8 – Calcar planing procedure.

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FEMORAL TRIALING REDUCTIONVerify the etched size on the rasp and trials before performing a trial reduction. Modular Neck Trials and Femoral Head Trials (Fig. 9) are available to assess proper component position, joint stability, range of motion, and leg length.

NOTE:ForStandardoffset,utilizetheSILVER-coloredModularNeckTrialsthataremarked“STD”.ForLateraloffset,utilizetheBLACK-coloredModularNeckTrialsthataremarked“LAT”.

Once the acetabular cup implant and Acetabular Trial Insert are also in place, you can perform a trial reduction of the construct.

Checktheleglengthandoffsetofthefemurbyreferencing the lengths measured prior to dislocation of the hip. It is important at this stage to reposition the legexactlywhereitwasduringthefirstmeasurement.Adjust the neck length by changing the Femoral Head Trial to achieve the desired result.

Remove all of the trial components when trial reduction is complete.

Figure 9 – Femoral stem trialing procedure.

10

FEMORAL STEM

INSERTION OF THE FEMORAL STEMInsert the femoral stem implant into the canal until it will no longer advance with hand pressure, which is approximately1mmto2mmabovethefinalseatedposition (Fig. 10). The Threaded Femoral Stem Inserter is threaded to allow the surgeon to control the femoral stemimplantduringinsertion.ABulletTipFemoralStemInserter is also available to allow full rotational freedom during insertion. The threaded insertion hole on the implant will accept either Femoral Stem Inserter.

NOTE: To reduce the potential for fracture, allow the femoral stem implant to follow the prepared envelope.

Apply the selected Femoral Stem Inserter to the femoral stem implant and begin to tap the handle with a mallet until the implant will no longer advance (Fig. 11).

NOTE:Donotcontinuetotrytoadvancetheprosthesisonce it has made contact with the cortical bone in the medial calcar.

Theprosthesisshouldbeseatedwhenthemostproximalpart of the plasma sprayed surface is level with the osteotomy line. If the implant does not advance with each strike of the mallet, stop insertion. If the stem is too proud, consider removing the component. Rasp additional bone from the areas that are preventing the insertion and insert the femoral stem implant again.

Figure 10 – Initial femoral stem placement.

Figure 11 – Seating the femoral stem.

11

Figure 12 – Impacting femoral head.

FEMORAL HEAD IMPACTIONFollowing the implantation of the femoral stem, as well as the acetabular cup and poly liner, it is necessary to implant the femoral head.

Irrigate, clean, and dry the femoral stem to ensure the taperisfreeofdebris.Beforereducingthehip,placetheappropriate femoral head onto the taper and lightly tap using the Universal Femoral Head Impactor (Fig. 12).

Oncetheentireconstructisimplanted,performafinalreductiontoassessandconfirmrangeofmotion,hipstability, and limb length.

12

FEMORAL STEM

ITEM NUMBER ITEM DESCRIPTION

01-10001-008-01 STANDARDFEMORALSTEM,SIZE8

01-10001-008-02 LATERALFEMORALSTEM,SIZE8

















01-10104-046-00 ACETABULARCUP,2-HOLE,46MMO.D.










01-10201-000-01 FEMORALHEAD,28MMDIAMETER,-4MMNECK

01-10201-002-01 FEMORALHEAD,28MMDIAMETER,+0MMNECK















01-10301-046-00 HXLPLINER,28MMI.D.X46MMO.D.,0DEGREE


















01-10901-015-00 BONESCREW,6.5MMDIAMETER,15MMLENGTH








01-30301-046-00 ACETABULARCUPLOCKINGRING,46MM










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11-18019-900-00 I-HIP INSTRUMENT SET

11-18019-900-01 I-HIP INSTRUMENT KIT 1





11-18001-008-00 FEMORALRESECTIONGUIDE,SIZE8-9-10



11-18002-900-01 BOXOSTEOTOME,1-PIECE

11-18003-900-00 RASP,RAT-TAILED

11-18004-900-00 REAMER, CALCAR

11-18004-910-00 T-HANDLE,CALCARREAMER

11-18005-008-00 FEMORALSTEMRASP,SIZE8









11-18006-008-01 STANDARDMODULARNECKTRIAL,SIZE8-9-10

11-18006-008-02 LATERALMODULARNECKTRIAL,SIZE8-9-10





11-18012-028-00 FEMORALHEADTRIAL,28MMDIA,-4MMNK

11-18012-028-02 FEMORALHEADTRAIL,28MMDIA,+0MMNK

11-18012-028-04 FEMORALHEADTRIAL,28MMDIA,+4MMNK













11-18015-900-00 FEMORALSTEMINSERTER,THREADED

11-18016-900-00 FEMORALSTEMINSERTER,BULLETTIP

11-18017-900-00 FEMORALHEADIMPACTOR,UNIVERSAL

11-18119-900-00 FEMORALRASPHANDLE,STRAIGHT

11-18030-900-00 FULLSIZEOUTERINSTRUMENTCASE

11-18035-900-00 OUTERINSTRUMENTCASELID

11-18020-900-00 I-HIPINSTRUMENTKITLID

11-18020-900-11 BOTTOMI-HIPINSTRUMENTTRAY1

11-18020-900-21 TOP I-HIP INSTRUMENT TRAY 1

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FEMORAL STEM



11-18100-938-00 ACETABULARREAMER,38MM



























11-18102-001-00 ACETABULARREAMERDRIVERHANDLE,OFFSET

11-18104-900-00 ACETABULARREAMERDRIVER,STRAIGHT








11-18105-000-00 ACETABULARCUPIMPACTORHANDLE

11-18105-900-50 ACETABULARCUPIMPACTORHANDLETOMMYBAR

11-18106-900-00 ACETABULARCUPPOSITIONINGGUIDE

11-18107-000-00 DRILLGUIDE

11-18108-925-00 DRILLBIT,3.2MMDIA,40MMLENGTH

11-18108-935-00 DRILLBIT,3.2MMDIA,50MMLENGTH

11-18109-900-00 ANGLEDDRILLDRIVER

11-18110-900-00 DEPTHGAUGE

11-18111-900-00 UNIVERSALJOINTSCREWDRIVER

11-18112-900-00 LINERIMPACTORHANDLE

11-18113-000-00 LINERIMPACTORHEAD,28MM



11-18118-046-28 ACETINSERTTRIAL,46MMO.D.X28MMI.D.























ICONACY Orthopedic Implants, LLC4130 Corridor Drive

Warsaw, Indiana 46582U.S.A.

+1 (574) 269-4266www.iconacy.com

91-10001-100-00 | Rev. 1112 | ©2012 ICONACY Orthopedic Implants

This technique is written based on the advisement of the product’s surgeon developers. Information on the products and procedures contained in this document is of a general nature and does not represent or constitute medical advice or recommendation. Each surgeon’s approach may vary. Variations to the technique will depend on the patient’s anatomy and the intraoperative surgical judgement of the surgeon. Please refer to the package insert for important product information, including, but not limited to, indications, contraindications, warnings, precautions, adverse effects, and sterilization.

femoral stem surgical techniquefemoral neck. use a one-piece box osteotome (fig. 5) to remove this...

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