Sirius Cemented Femoral Hip Stem Surgical Technique...Sirius Cemented Femoral Hip Stem 6 Femoral Canal Opening It is important to enter the femoral canal at the piriformis fossa to

Surgical Technique

Sirius Cemented Femoral Hip Stem

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Sirius Cemented Femoral Hip Stem Table of ContentsIndications and Contraindications....................................................................................................................................................2Preoperative Planning .......................................................................................................................................................................3Templating Procedure ........................................................................................................................................................................4Surgical Exposure ...............................................................................................................................................................................4Femoral Neck Resection......................................................................................................................................................................5Preparation of the Acetabulum and Insertion of the Acetabular Component.........................................................................5Femoral Canal Opening......................................................................................................................................................................6Femoral Canal Reaming......................................................................................................................................................................7Femoral Canal Broaching....................................................................................................................................................................8Stem Trial Reduction...........................................................................................................................................................................9Femoral Canal Final Preparation.....................................................................................................................................................10

Cement Preparation

Femoral Cementing ..........................................................................................................................................................................10Cement DeliveryPressurization

Femoral Stem Insertion.....................................................................................................................................................................12Final Reduction..................................................................................................................................................................................13Component Removal.......................................................................................................................................................................14Cement-in-Cement Revision Procedure........................................................................................................................................14

Cement Mantle PreparationTrial Insertion and ReductionCement InsertionFinal Implant Insertion

Ordering Information.......................................................................................................................................................................17

The Biomet Sirius system and subsequent operative technique were developed in con-junction with Mr. Peter Brydon (Melbourne, Australia), Mr. Alun John (Cardiff, UK), Prof. Azhar Merican (Kuala Lumpur, Malaysia) and Dr. Gary Nielsen (Brisbane, Australia).

Biomet, as the manufacturer, does not practice medicine and does not recommend spe-cific products or techniques for individual patients.

This brochure represents the surgical technique utilized by the developing surgeons of the Sirius femoral stem. Acetabular components are selected, as appropriate for each patient, by each individual surgeon. The acetabular components included in this brochure are examples of available technology that are compatible with the Sirius femoral stem and are not necessarily utilized by the Sirius development team. Please see the Sirius product labelling and alternative acetabular components available through Biomet at www.biomet.com

Acknowledgment

Indications For Use 1. Non-inflammatory degenerative joint disease including

osteoarthritis and avascular necrosis

2. Rheumatoid arthritis

3. Correction of functional deformity

4. Treatment of non-union, femoral neck fracture, and trochanteric fractures of the proximal femur with head involvement, unmanageable by other techniques

5. Revision procedures where other treatment or devices have failed

The Sirius Femoral Hip Stem is intended for cemented use only and may be used in partial and total hip arthroplasties.

ContraindicationsAbsolute contraindications include: infection, sepsis, and osteomyelitis.

Relative contraindications include:

1. Uncooperative patient or patient with neurologic disorders who are incapable of following directions

2. Osteoporosis

3. Metabolic disorders which may impair bone formation

4. Osteomalacia

5. Distant foci of infections which may spread to the implant site

6. Rapid joint destruction, marked bone loss or bone resorption apparent on roentgenogram

7. Vascular insufficiency, muscular atrophy, or neuromuscular disease

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Preoperative PlanningSelection of the appropriate femoral component is attained through careful preoperative planning. This can be achieved either manually by means of X-ray templates or using a digital templating system (Figures 1 and 2).

Manual Preoperative PlanningThe Sirius femoral templates are overlaid onto the Anterior Posterior radiograph to best decide the correct resection level, adequate implant size and cement mantle thickness. X-ray magnification should be taken into consideration when selecting templates.

Digital Preoperative PlanningSirius digital templates are available from various digital template providers. When using digital templates, it is necessary to use a magnification marker with a known dimension to calibrate the image.

Once the correct magnification has been determined, the digital templating system can be used to best decide the correct implant required to help restore the patient’s natural anatomy.


Figure 1 Figure 2


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Templating Procedure The aim of templating is to plan for correct size and position of the implants, to restore the hip center, femoral offset and leg length.

Templating typically begins on the contralateral hip with a true A/P radiograph (Figure 3). First the correct cup size is chosen, and then the center of rotation of the femoral head is identified.

On the operative side, mark the anatomic center of the femoral head. Using the appropriate template, align the midline of the implant with the anatomical axis of the femoral canal. Move the template vertically so the selected head level mark overlays the planned center of the femoral head. Select the stem size by choosing the stem which will allow an adequate cement mantle. The dotted line on the templates represents the width of a 1.5 mm cement mantle for stem size B, and a 2 mm cement mantle for stem sizes C–G. Stem oversizing should be avoided. It is recommended that a sufficient bed of proximal cancellous bone be preserved for bone cement interlock. Once the appropriate stem size has been chosen, note the resection level and corresponding stem depth mark.

Surgical ExposureThe Sirius stem can be implanted using any of the standard approaches for total hip arthroplasty. Irrespective of which approach is used, the goal is to gain adequate exposure of the proximal femur (Figure 4). This is essential for effective preparation of the endosteal surface of the bone, cementation and correct alignment of the prosthesis.

Figure 4Figure 3

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Femoral Neck ResectionOnce the hip has been dislocated, complete the femoral neck resection. As the Sirius stem is a non-collared implant, the resection angle and level are not critical. However, if needed, a femoral neck resection guide is available. Place the guide over the neck, parallel to the longitudinal axis of the femur (Figure 5). Then, move the guide along this axis to match the resection level determined by preoperative templating and make the appropriate neck resection (Figure 6).

Preparation of the Acetabulum and Insertion of the Acetabular ComponentBiomet cemented or cementless acetabular components can be used with the Sirius cemented femoral hip stem. Insertion of the chosen prosthesis must be carried out as instructed in the relevant operative technique for the chosen acetabular component.

Figure 5 Figure 6


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Femoral Canal OpeningIt is important to enter the femoral canal at the piriformis fossa to prevent malpositioning and or undersizing of the femoral component. The modular box chisel (Figure 7) or starter drill (Figure 8) may be used, according to the preferred technique. Either method helps to clear the femoral canal postero-laterally and to line-up the starter reamer without impingement on the greater trochanter.

• The modular box chisel is attached onto the clamping broach handle.

• The starter drill is connected to the reamer T-handle.

The curved starter rasp can then be utilized to further open the proximal femoral canal and remove some cancellous bone from the calcar. Retain a layer of strong trabecular bone for optimal cement interdigitation.

Figure 7 Figure 8

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Femoral Canal ReamingInsert a single starter reamer on a T-handle (Figure 9) into the distal femoral canal to a level appropriate for the component templated on the preoperative X-rays. Care should be taken to insert the reamer straight into the medullary canal. Correct reaming will allow the broaches and subsequent femoral component to be inserted in the correct position.

Note: Power reamers should not be used to prepare the femoral canal as damage to the endosteal surface of the femur compromises cement interdigitation into cancellous bone.

Figure 9


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Femoral Canal BroachingWhen preparing the proximal femur, insert and remove the broaches carefully to control the anteversion of the femoral stem. A version rod can be threaded onto the clamping broach handle to guide broach insertion.

Connect the broaches to the clamping broach handle (Figure 10). Use them in a sequential manner starting with the smallest broach (i.e. size A). Continue to insert progressively larger broaches until the planned size is achieved.

Note: Do not strike the threaded version rod. Impaction should only occur on the clamping broach handle strike plate.

The final broach used indicates the size of the femoral stem to be implanted (Figure 11). The Sirius broaches have a 1.5mm thick cement mantle built-in for stem size B, and a 2mm cement mantle for sizes C–G. Take care not to over-rasp the femoral canal and remove too much cancellous bone. A proximal layer of 2–3 mm of strong cancellous bone should be preserved.

The broaches have depth indicator holes corresponding to the depth marks on the definitive implants and X-ray templates. These depth marks are 3.5 mm apart, vertically.

Figure 10 Figure 11

Not a depth indication hole

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Stem Trial ReductionWith the final broach left in situ, select the appropriate trial neck size, corresponding to the stem body size (view table below), and attach it to the broach trunnion.

Neck Size 32 34 38 44 50

Stem body Size B B,C C,D,E D,E,F F,G

The trial neck replicates the exact neck geometry of the femoral stem.

Biomet Type 1 taper heads are available in a wide array of diameters and neck lengths. This allows for the adjustment of femoral offset, leg length, good joint stability and large range of motion. Attach the desired modular trial head to the trial neck (Figure 12). Perform a trial reduction using the head pusher. Assess range of motion, soft tissue tension, joint stability and leg length. Repeat the trial reduction procedure with different neck and head offsets and, if needed, different broach implantation depths until joint stability and desired leg length have been achieved.

The broach insertion depth can be adjusted and held in position by placing a trial pin through the corresponding depth indication hole. If the leg is too long but the offset is correct, the broach can be impacted further. If the leg is too short but the offset is correct, the broach can be disimpacted and held out to length by placing the provided trial pin through the depth insertion hole that lies at the level of the neck cut.

Once the trial reduction has been completed, note the insertion depth and medial/lateral position of the final broach implanted by marking the position of the depth hole closest to the neck cut.

Carefully remove the trial modular head from the rasp. Reattach the rasp handle to the broach and remove the broach from the canal. Care must be taken to avoid damaging the cancellous bone in the proximal femoral canal.

Figure 12


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Femoral Canal Final PreparationBone Bed PreparationMeasure the distal plug size by using the plug sizers or by measuring the intramedullary canal diameter on the preoperative radiographs. The distal plug must be tight within the canal to create an adequate seal and allow for cement pressurization.

Mount the appropriate plug size onto the plug inserter. The plug inserter is designed to place the plug approximately 14 mm distal to the tip of the final prosthesis (Figure 13). Once tightly seated in the femoral canal, the plug will detach itself from the inserter upon removal.

Thoroughly clean the femoral shaft using a pulse lavage, and dry the femoral shaft to remove any loose debris from the cancellous surface of the canal (Figure 14). This final preparation is essential to maximize cement penetration into the cancellous bone, and therefore achieve a strong bone/cement micro-interlock.1,2 Utilizing a pulse lavage may also minimize the risk of embolism during cement insertion.3

Figure 13

Femoral CementingCement PreparationThe Optivac cartridge mixing system allows cement mixing and collection under vacuum. This minimizes the risk of exposure to monomer fumes and contact with cement. The Optivac system provides a reproducible high quality cement with reduced porosity and improved fatigue strength. Once the cement is mixed and collected under vacuum, load the cement cartridge into the cement gun.

Figure 14

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Cement DeliveryIntroduce cement into the plugged femoral canal in a retrograde fashion, moving the cement gun nozzle out as the canal fills with cement (Figure 15).

Note: Delivery of cement to the bone, should never be done when the cement is in low viscosity stage.

Figure 16

PressurizationOnce the femoral canal is filled with cement, snap off the redundant nozzle and apply the proximal pressurizer and support plate against the resected femoral neck to pressurize the cement (Figure 16). A positive sign of pressurization is marrow extrusion from the proximal femur. Cement pressurization has been shown to achieve greater penetration into the cancellous bone, thereby improving the bone-cement interlock and enhancing cement strength.4,5

Pressure needs to be maintained until the cement is sufficiently doughy to withstand bleeding from the endosteal surface of the femoral canal. The cement polymerization time varies depending on the type of cement used, temperature and humidity.

Figure 15


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Figure 17 Figure 18

Femoral Stem InsertionSelect the appropriate Sirius stem. Hollow winged and wingless distal stem centralizers are supplied with the definitive implant. The wingless centralizer is used in femoral canals of 10 mm diameter or under. The centralizer has a hollow cavity to prevent tip loading and allow for controlled subsidence within the cement mantle.

Mount the prosthesis onto the stem inserter by pulling on the T-handle which depresses the ball bearing locking mechanism. Place the tip of the inserter into the slot on the stem shoulder. Release the T-handle and the stem is locked (Figure 17).

Note: The stem can also be inserted into the femoral canal using the stem pusher.

When the cement is at the appropriate consistency, introduce the Sirius stem into the center of the femoral canal. The T-handle can be used as a visual aid to control the version of the stem during insertion and cement polymerization.

To facilitate cement pressurization during insertion, occlude the medial aspect of the femur between the calcar and the stem with your thumb whilst the stem is slowly introduced. The stem must be inserted to the predetermined depth mark (Figure 18). When the final implant position is achieved, remove all excess cement from the resected femoral neck with a curette. Maintain pressurization and stem position until the cement has fully hardened, ensuring that the stem does not back out during cement polymerization.

Note: The stem inserter is designed to allow for a small degree of rotation in relation to the stem. A small movement of the inserter or leg during the polymerization process does not result in unwanted stem rotation within the cement mantle.

Note: The stem inserter should not be hit during implant insertion. If impaction is required, utilize the stem pusher.

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Final ReductionIf desired, once the cement has cured, complete a further trial reduction using the appropriate trial heads. Check the range of motion, joint stability, soft tissue tension and leg length.

After fully seating the femoral component (Figure 19), position the modular femoral head onto a dry and clean surface of the trunnion with hand pressure only. Fully seat the modular head by means of a gentle tap utilizing the femoral head pusher and mallet.

Figure 19

Note: Modular heads should never be heavily impacted onto the trunnion as this may cause damage to the surface of the modular head.

Once the definitive modular femoral head has been attached to the femoral stem, reduce the hip joint.


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Cement-in-Cement Revision ProcedureCement-in-cement revision of the femoral component can be performed in cases where the femoral cement mantle appears intact at the time of revision surgery. It is an attractive option as removal of well fixed cement can be difficult and as such increases the risk of excessive bone stock loss, fracture or shaft perforation.6 Indications for such a surgical technique include: 6

• femoral stem removal for improved access to the acetabulum

• exchange of a monoblock stem with a damaged head

• exchange of a modular stem with a damaged or incompatible trunnion

• change of version, length or offset for the treatment of instability or leg length discrepancy

• stem fracture

• aseptic loosening at the prosthesis / cement interface

Note: Due to its small dimensions, the Biomet Sirius stem is ideally suited to perform cement-in-cement revisions. In many cases, the Sirius stem can be inserted into the cemented cavity left after removal of primary implants without requiring any distal cement removal.

Figure 20

Femoral Stem RemovalShould a Sirius femoral component ever require removal, a stem removal instrument and slide hammer are available in the universal head/stem removal tray.

Position the stem removal instrument on either side of the trunnion and use the slide hammer to exert sufficient force to remove the femoral stem (Figure 20).

Clear the proximal cement, paying special attention to the trochanteric area.

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Cement Mantle PreparationAfter removal of the existing stem, take care to avoid debris or soft tissues entering the femoral canal that could compromise the cement-in-cement technique. Once the revised stem is extracted, should there be any concerns about the integrity of bone cement interface, resect the femoral neck 2–3 mm below the existing resection.

If inspection of the cement cavity reveals loose cement particles, soft tissue at the bone cement interface or any other visible damage distal to the lesser trochanter, the cement-in-cement method should be abandoned and a different revision technique should be used.

Following removal of the original stem, if the cement cavity is not large enough to accommodate the Sirius stem, and providing the cement is thick enough, the excess cement mantle can be removed using cement reamers or high speed burs.

Note: Irrigation whilst reaming the cement mantle is highly recommended.

Trial Insertion and ReductionInsert a stem trial with the appropriate trial neck to ensure the correct stem size can be implanted. The Sirius stem and neck trials replicate the exact stem geometry of the real prosthesis. The trial stem insertion depth can be adjusted and held in position by placing a pin through the corresponding depth indication hole. The thickness of the future cement mantle and distal centralizer must be taken into account when trialling. If need be, further cement mantle reaming may be carried-out, using the cement reamer, until the desired stem position is achieved.

Perform a trial reduction to assess the range of motion, soft tissue tension, leg length and joint stability.

Note the insertion depth mark of the trial stem to facilitate the future insertion of the definitive implant (Figure 21).

Figure 21


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Cement-in-Cement Revision Procedure (cont.)Cement InsertionThoroughly clean the new cement cavity using a pulse lavage and dry the cavity to remove any remaining debris. Optivac is mixed and collected under vacuum. Insert the cement in a retrograde fashion with a cement gun using a revision nozzle and pressurized as described on page 11. The cement cavity must be completely filled.

Final Implant InsertionSelect the final implant matching the size and offset of the last trial stem used. Fit the hollow wingless distal stem centralizer onto the implant. Mount the assembly onto the stem inserter and carefully insert it into the femoral canal to the required depth (Figure 22). It is essential to maintain the desired stem anteversion during stem insertion and pressurization.

Once the cement has set, perform a final trial reduction before implanting the definitive modular femoral head.

Figure 22

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Stem Length

Horizontal Offset

Vertical Offset

Femoral size

Stem Length*

Horizontal Offset

Vertical Offset

CCD Angle

32-B B 100 32 16 125

34-B B 100 34 18 125

34-C C 110 34 18 125

38-C C 110 38 20 125

38-D D 110 38 20 125

38-E E 110 38 20 125

44-D D 110 44 24 125

44-E E 110 44 24 125

44-F F 130 44 24 125

50-F F 130 50 27 125

50-G G 130 50 27 125* Measured from resection level to the distal tip.

Sirius Sizing Chart

Sirius Cemented Femoral Stem

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Implants

Sirius Stems and Centralizers

Product Part Number Description Size

51-19933251-19933351-19933451-19933551-19933651-19933751-19934151-19934251-19934351-19935151-199352

Sirius Femoral Hip Stem

32-B34-B34-C38-C38-D38-E44-D44-E44-F50-F50-G

51-199300 Sirius Winged Centralizer

51-199301 Sirius Wingless Centralizer

Product Part Number Description

XRAY31-149100 Sirius Acetate X-ray Template Set

Note: The Sirius stem is packaged with the winged and wingless centralizer options.

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Sirius Broach Tray


597044 Sirius Broach Tray –

596044 Sirius Broach Instrument Case (Empty) –

31-14910231-14910331-14910431-14910531-14910631-149107

Sirius Broach

BCDEFG

31-14912231-14912331-14912731-14912431-14912531-149126

Sirius Trunnion

3234-B34-C

384450

31-149160 Sirius Hip T-Handle Inserter –

31-555408 Sirius Straight Clamping Broach Handle –

31-149163 Sirius Standard Plug Inserter –

4197 Support Plate for Femural Pressurizer II –

31-149164 Sirius Stem Pusher (Optional Instrument) –

31-149110 Sirius Stem Trial Pin –

Instruments


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597045 Sirius Trial Tray –

596045 Sirius Trial Instrument Case (Empty) –

31-14910131-14913231-14913331-14913431-14913531-14913631-149137

Sirius Trial Stem

ABCDEFG

31-149115 Sirius Cement Reamer –

Sirius Trial Tray

Optional Instruments

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General Instrumentation


X31-400061 Extended Stroke Slap Hammer

X31-400059 J-Hook Stem Extractor


31-601565 Taperloc Complete General Instrument Case —

31-399999 Ergonomic Head Driver —

31-473620 Reamer T–Handle —

X31-400003 Exact Femoral Resection Guide Alliance —

428195 Starter Reamer —

51-222221 Initial Starter Rasp —

466365 Pilot Tipped Twist Drill —

31-473794 Exact Modular Calcar Planer 42 mm

31-400000 Exact Bone Plug Inserter —

31-400100 Exact I-M Plug Inserter —

31-473678 Gibbs Hollow Chisel —

Femoral Stem Removal Instruments


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430900 Femoral Pressurizer II

Cement Accessories

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Notes

References 1. Miller, J. and Johnson, J. Advances in Cementing Techniques in Total

Hip Arthroplasty in The Art of Total Hip Arthroplasty. Grune & Stratton Inc, 1987.

2. Breusch S.J., Lavage Technique in Total Hip Arthroplasty: Jet Lavage Produces Better Cement Penetration than Syringe Lavage in the Proximal Femur. Journal of Arthroplasty. 15(7):921-7, 2000.

3. Christie, J. et al. Medullary Lavage during Cemented Hemiarthroplasty, Journal of Bone and Joint Surgery [Br]. 77- B:456-9, 1995.

4. Reading A.D., et al. A Comparison of 2 Modern Femoral Cementing Techniques: Analysis by Cement-bone Interface Pressure Measurements, Computerized Image Analysis, and Static Mechanical Testing. Journal of Arthroplasty. 15(4):479-87, 2000.

5. Breusch, S. Cementing Techniques in Total Hip Replacement: Factors Influencing Survival of Femoral Components, In Bone cements and Cementing Technique. ed by Walenkamp, G. and Murray, D. Springer Verlag, 2001.

6. Duncan, W. et al. Revision of the Cemented Femoral Stem using a Cement-in-Cement Technique: A Five to 15 Year Review. Journal of Bone and Joint Surgery [Br]. 91-B(5): 577-82, 2009.

©2014 Biomet Orthopedics • Form No. BMET0240.0 • REV0614

This publication and all content, artwork, photographs, names, logos and marks contained in it are protected by copyright, trademarks and other intellectual property rights owned by or licensed to Biomet or its affiliates, and must not be used, copied or reproduced in whole or in part without the express written consent of Biomet.

This publication is intended for health care professionals and is not for redistribution.

Biomet does not practice medicine and does not recommend any particular orthopaedic implant or surgical technique and is not responsible for the kind of treatment selected for a specific patient. The surgeon who performs any implant procedure is responsible for determining and utilizing the appropriate techniques for implanting prosthesis in each individual patient.

For complete product information regarding indications, contraindications, precautions, warnings and sterilization, see the instructions for use packaged with the device, and on which can also be located on www.biomet.com.

Please check for local product clearances and reference product specific instructions for use.

Biomet Orthopedics P.O. Box 58756 E. Bell DriveWarsaw, Indiana 46581-0587 USA

Note: The Legal Manufacturer for the instruments and bone cement listed in this operative technique is shown on the individual labels, packaging or instrument set labels. Further refer to the labeling or package inserts of the instruments and bone cement for reference to the CE mark and Notified Body Number.

www.biomet.com

European RepresentativeBiomet UK Ltd.Waterton Industrial EstateBridgend, South WalesCF31 3XA UK

www.biometeurope.com

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Documents

Sirius Cemented Femoral Hip Stem Surgical Technique...Sirius Cemented Femoral Hip Stem 6 Femoral Canal Opening It is important to enter the femoral canal at the piriformis fossa to