Total Knee Replacement (Scorpio)

Orthopaedics

Scorpio Total Knee System Surgical Protocol

AR

• Fixed and Mobile Surgical Protocol • Anterior Referencing Technique

Table Of Contents

Xcelerate™ Instrumentation Surgical Technique for Scorpio® Single Axis Total Knee System Scorpio® A.R. Surgical Technique Exposure ..................................................................................2 Femoral Preparation ..............................................................3 Femoral IM Alignment Epicondylar referencing ....................................................4 Femoral IM Alignment External Rotation Option..................................................6 Anterior Skim Cut..............................................................8 Distal Femoral Resection ................................................11 Femoral Sizing..................................................................15 Femoral Anterior, Posterior and Chamfer Resections..................................................16 Patellar Chamfered Preparation ....................................18 Option 1 – Punch Technique ........................................................19 Option 2 – Rasp Technique ..........................................................20 Notch Preparation for Scorpio® PS only ..................21 Option 1 – Punch Technique ........................................................21 Compacting Technique..............................................22 Option 2 – Saw Technique ............................................................23 Compacting Technique..............................................24 Tibial Preperation ................................................................25 Option 1 – Extramedullary Technique ........................................25 Tibial Resection Level ................................................27 Proximal Tibial Resection ..........................................29 Option 2 – Intramedullary Technique ........................................30 IM Rod Placement......................................................30

Tibial Intramedullary Alignment Option ................31 Rotational and Varus/Valgus Alignment ..................32 Flexion/Extension Alignment....................................34 Tibial Resection Level ................................................34 Proximal Tibial Resection ..........................................36 Option 1

Scorpio® Fixed Bearing Technique Tibial Baseplate Preparation ..............................................37 Scorpio® Tibial Component Sizing ................................37 Tibial Component Alignment ........................................38 Tibial Keel Punching ......................................................39 Option 2

Scorpio®+ Mobile Bearing Technique Tibial Baseplate Preparation ..............................................41 Soft Tissue Balancing ......................................................41 Xcelerate™ Knee Balancer ................................................42 Tibial Trial Positioning and Reduction ..........................43 Assessment of Fit and Stability ......................................44 Tibial Preparation ............................................................45 Insert Assembly ................................................................46 All-Poly Tibial Punching ................................................47 Patellar Preparation..........................................................48 Implantation ........................................................................49 Tibial Component............................................................49 Tibial Bearing Insert Assembly ......................................50 Implantation of Femoral Component ..........................50 Implantation of Patellar Component ............................51 Closure..............................................................................51

A.R. Technique

i

Scorpio® Single Axis Knee System Surgical Protocol Using Xcelerate™ Knee Instruments Acknowledgements The following surgeons have contributed extensively to the development of the Scorpio® Knee prostheses: James D’Antonio, MD Ormonde Mahoney, MD Lawrence Morawa, MD Thomas Schmalzried, MD Peter Bonutti, MD Donald Reilly, MD Ph.D Stephen Incavo, MD

ii

A.R. Technique

Scorpio® Product Family

Form, Function & Flexibility

The Scorpio® family offers a complete range of fixed bearing, mobile bearing and revision components, all of which share a single design philosophy, with three benefits

1

Less An teri or Kn ee Pa i n

2

Fa s ter Pa ti ent Reh a b i l i t a ti on

3

Im p roved Liga m ent St a b i l i ty

A.R. Technique

1

Exposure

Use a standard anteri or midline incision ( Fi g u re 1). Previous incisions may be used or incorpora ted to decrease the risk of skin slough. Enter the capsule through a medial parapatellar approach approximately 1 cm from the medial border of the patella (Figure 2).

Figure 1

2

A.R. Technique

Figure 2

Incise the quadriceps mechanism longitudinally to allow adequate patellar eversion and sufficient knee flexion (Figure 3).

Figure 3

Femoral Preparation Femoral Intramedullary Alignment Use a 3/8" diameter drill to enter the intramedullary canal of the femur (Figure 4). The drill hole is located approximately 1cm anterior to the femoral attachment of the posterior cruciate ligament and s l i gh t ly medial to the midline of the distal femur (Figure 5).

Figure 4

Rem oval of o s teophytes from the margins of t h e i n tercon dylar notch may aid iden ti f i c a ti on of landmarks. It is recom m en ded that the dri ll hole be sligh t ly enlarged. This can be accomplished by toggling the drill, using a rongeur, or inserting an axial reamer.

Figure 5 Femoral IM Hole Placement

3/8” DRILL HOLE

A.R. Technique

3

Femoral Preparation Femoral IM Alignment - Epicondylar referencing Rotational Alignment can be determined in one of two ways: Option 1 - Femoral IM Alignment with Epicondylar Referencing Place the epicondylar referencing guide (Fig.6) into the intercondylar notch hole (Fig. 7) and reference either: 1) the trochlear groove using the vertical bar; or 2) the epicondyles using the horizontal slotted bar. Either of the above methods will result in a line parallel to the epicondylar axis.

Figure 7

Figure 6

Epicondylar Reference Guide

4

A.R. Technique

Once rotation is set appropriately, mark the epicondylar axis through the slots provided using electrocautery or an osteotome. (Fig. 8) Remove the guide. The Fem oral Al i gn m ent Gu i de is de s i gn ed for use on either the left or right knee and can be set at 5 or 7 degrees of valgus. Place the 5/16” T-Handle Rod through the back of the Femoral Alignment Guide and set the instrument to the preoperatively determined angle by pulling the knob on the Femoral Al i gn m ent Guide and locking it in the appropriate notch. In s ert the Fem oral Al i gn m ent Gu i de into the intramedullary hole (Fig. 9), lining up the marks on the distal femur with the slots on the Fem oral Al i gn m en t Guide. (Fig. 10) Use two 1/8” diameter pins through the distal holes to secure the Femoral Alignment Guide to the distal femur.

Figure 8

Figure 9

Mark Position Through Slots Femoral Alignment Guide

Figure 10

T-Handle Rod

A.R. Technique

5

Femoral Preparation

Opti on 2 - Fem oral IM Al i gn m ent with 3° Extern a l Rotation Guide In s ert the Fem oral Al i gn m ent Gu i de into the intramedullary hole. (Figs. 11, 12)

Figure 11

Figure 12

6

A.R. Technique

Place the 3 degree External Rotation Guide into the slots of the Femoral Alignment Guide taking care to assemble the guide in the appropriate left or right orientation. Use this guide to judge equal amounts of medial and lateral posterior condyle. (Fig.13) If the posterior condyles are a deficient reference due to a bone deformity, the guide should be align ed with the ep i con dyle using the epicondyle referencing guide. Use two 1/8” diameter pins through the distal holes to secure the Femoral Alignment Guide to the distal femur. The External Rotation Guide may be removed. Two sets of holes are provi ded for use with small or large knees.

Figure 13

3° External Rotation Guide

A.R. Technique

7

Femoral Preparation Anterior Skim Cut Assemble the stylus to the Anterior Resection Guide by depressing the button on the stylus and fully seating it into the hole on the Anterior Resection Guide. Release the button to lock the stylus in place. Insert the Anterior Re s ecti on Gu i de into the two anteri or holes on the Femoral Alignment Guide. (Figs. 14, 15)

Stylus Locking Button

Anterior Resection Guide

Figure 14

Figure 15

8

A.R. Technique

The length of the stylus may be easily adjusted by sliding it to the ap propriate point. The tip of the stylus indicates the exit point of the sawblade when the final femoral resections are made. Adjusting the tip of the stylus to reference off the high point of the anterior lateral cortex will result in a conservative anterior cut, eliminating the risk of notching the cortex. (Fig. 16)

FIGURE 16

A.R. Technique

9

Femoral Preparation

Prior to resection, check the saw exit level around the superomedial and superlateral sides of the anterior cortex with a sawblade or an Osteonics Bladerunner. (Fig. 17) Tighten the side screw with the hex wrench to lock the re s ecti on guide in place . ( Fi g . 1 8 ) The stylus can be removed before the resection is made. Use a .050” thick sawblade to make the resection. (Fig. 19) After the resection is completed, loosen the side screw and remove the Anterior Skim Resection Guide, leaving the Femoral Alignment Guide pinned in place. “ Because more lateral bone than medical bone will be resected from the anterior femur, cut the medial side first - it should be a relatively small wafer of bone. If it is a large medial resection, double check that the guide is properly externally rotated.”

Figure 17

Stephen Incavo, MD

Figure 18

Side Screw

Figure 19

10

A.R. Technique

Distal Femoral Resection Assemble the 8mm or 10mm Distal Resection Guide to the Distal Resection Guide Stand by placing the Guide over the pegs. These guides are magnetised to assure correct assembly. The resection guide may then be locked into place by pushing in and turning the locking knob 1/4 turn clockwise. (Fig. 20)

Magnetized Distal Resection Guide Stand Distal resection Guide Locking Knob

Figure 20

A.R. Technique

11

Femoral Preparation

Sl i de the assem bly into the anteri or holes of t h e Femoral Al i gn m ent Guide and lower the assembly down until the Distal Resection Guide sits flush on the anterior skim resection. Tighten the side screw to secure the guide (Fig. 21)

Figure 21

Side Screw

12

A.R. Technique

Prior to pinning the Distal Femoral Resection Guide to the femur, and optional external alignment check may be carried out. Attach the Alignment Guide Handle to the Distal Femoral Resection Guide and insert an External Al i gn m ent Rod into the handle. Al i gn m ent is correct when the rod intersects the centre of the femoral head and roughly parallels the axis of the femur in the lateral view. (Fig. 22) Drive two 1/8” headless pins into the holes marked “0”. (Fig. 23) The Distal Resection Guide comes in 8mm or 10mm Re s ecti on con f i g u ra ti ons and all ows 8mm or 10mm of bone to be rem oved from the distal femu r. Pinning thro u gh the “X” pin hole wi ll aid in furt h er securing the guide. Note: “O” hole gives option of +2 and +4mm. No option if you pin in +2 or +4mm holes.

Figure 22

Alignment Rod

Alignment Guide Handle

Figure 23

A.R. Technique

13

Femoral Preparation

O n ce sec u red ( Fi g . 2 4 ) rem ove the Distal Fem ora l Alignment Guide by first removing the 1/8” pins in the distal femu r. Rem ove the IM Rod , t h en slide out the Distal Femoral Alignment Guide and Distal Resection Guide Stand, leaving only the Distal Resection Guide in place. Make the distal resection using a .050” thick sawblade and remove the resection guide. (Fig. 25) An ad d i ti onal 2mm or 4mm of distal femur may be re s ected by sliding the Distal Re s ecti on Gu i de up of f headless pins an placing it back on so that the pins go t h ro u gh ei t h er the “ + 2 ” or “ + 4 ” h o l e s . Re s ect the remaining bone. No te : If the “X” pin hole is used , this pin must be removed prior to repositioning or removing the Distal Resection Guide.

Figure 24

Figure 25

14

A.R. Technique

Femoral Sizing The sizing guide should be used to determine the appropriate size cutting block and femoral component. The size can be determined by placing the feet of the guide under the posterior femoral condyles. The top bar should be collapsed until it seats flush on the anterior skim resecti on . In the event of in-between sizing, the smaller size should be selected. (Fig. 26)

Figure 26

A.R. Technique

15

Femoral Preparation Femoral Anterior, Posterior and Chamfer Resections Position the Femoral Cutting Guide on the distal femur. The anterior lip of the block should sit flush against the resected anterior femur. (Fig. 27) Using the pin driver and a mallet, drive the two serrated pins into the femur. (Fig. 28) Additional stability may be achieved by using towel clamps on the side of the blocks. “If the bone is sclerotic, pre-drill the hole with a 1/8” drill bit.” David Markell, MD

Figure 27

Figure 28

16

A.R. Technique

Complete the remaining four femoral bone resections. (Fig. 29) The order of the resections is critical: the sequence is: 1. posterior condyles 2. posterior chamfer 3. anterior cortex 4. anterior chamfer.

Figure 29

A.R. Technique

17

Patellar Chamfered Preparation The Scorpio® Universal Preparation Block Instrument is used after completion of the five femoral bone cuts. • Select the appropriately sized Universal Notch Block. The block sits on the anterior, anterior chamfer and distal cuts. The anterior geometry represents the left and right lateral flanges of the implant of the same size. The sides are marked LL and RL for left lateral and right lateral, respectively. • Po s i ti on the No tch Bl ock on the prep a red distal femur, aligning the lugs with the holes made by the Femoral Cutting Guide. Tap into place with the mallet (Figure 30). To further aid the positioning, note that the block is also the same width as the implant of its respective size.

• Once the Notch Block is seated flush against the anterior, anterior chamfer and distal cuts of the femu r, d ri ll 1/8" headless pins thro u gh the a n gl ed holes (“X”) on the anteri or and/or anterior chamfer surfaces of the block (there are 4 “X” holes each at 15°) (Figure 31). • Towel clamps may be used on the medial and lateral sides of the distal portion of the block. It is recommended to use at least the 2 anterior pin holes, even if towel clamps are used.

Figure 30

Figure 31

Scorpio ® Universal Notch Block

18

A.R. Technique

Femoral Preparation Patellar Chamfered Preparation Option 1: Punch Technique • Assemble the appropriately sized Patella Recess Punch onto the punch handle (Figure 32). • In s ert the rails of the Pa tella recess Pu n ch into the tracks at the distal end of the Notch Block. Start the cut from the distal su rf ace and adva n ce anterior/proximal (Figure 33). • Tap the end of the Scorpio® punch handle with the mallet to advance the punch.

NOTE: Take care that the handle is aligned with the track and rails that the punch passes through, so as to avoid jamming the instrument. • One complete pass of the punch through the track and full length of the block will clear the n ece s s a ry groove for the patella track . A s econ d a r y pass may be used , i f de s i red , to confirm all tissue is removed. • Rem ove the pins, towel clamps and the Universal Notch Block.

Figure 32 Patella Recess Punch

Scorpio® Punch Handle

Figure 33

A.R. Technique

19

Patellar Chamfered Preparation Option 2: Rasp Technique • As s em ble the Scorp i o ® p u n ch handle to the appropriately sized rasp (Figure 34). • S t a rt from the distal su rf ace and adva n ce to anterior/proximal so the entire rasp passes through the length of the block. The position of the rasp is constrained within the block.

• Continue cutting with the rasp until it rides flat on the top surface of the block. The groove is then completely prepared (Figure 35). NOTE: The rasp only cuts in one direction. • Rem ove the pins, towel clamps and the Universal Notch Block.

Figure 34

Scorpio® Rasp

Scorpio® Handle

Figure 35

20

A.R. Technique

Femoral Preparation Notch Preparation for Scorpio® PS only Option 1: Punch Technique N OT E : If the femoral bone is sclerotic, Option 2(Saw Technique) should be used for the notch preparation. • Assemble the appropriately sized Notch Punch to the punch handle. • Guide the Notch Punch into the tracks on the distal face of the Notch Block (Figure 36). The rails on the sides of the cutting edge fit into the tracks on the inside walls of the block. • Using a mallet, impact the Punch until it reaches the en d - s top and is fully seated in the No tch Bl ock (Figure 37). Remove the Punch from the tracks with a Slaphammer if necessary (Figure 38).

N OT E : It is not uncommon for the area ofbone being prepared to be removed by the punch at the time of extra c ti o n . In this instance , it is sti ll necessary to clean out remaining soft tissue and compact. NOTE: Using an osteotome or rongeur, remove the m a rg in of the interco n dylar bone nece s s a r y to en su re that all soft ti s sue is cl ea r ed from the intercondylar area of the femur. (It is important to remove all soft tissue in the femoral notch prior to co m pa cting bone to avoid future potential softtissue impingement).

• After punching pin, need to compact.

FIGURE 36

Notch Punch

Figure 37

Figure 38 Slaphammer

Notch Preparation Slaphammer Fitting

A.R. Technique

21

Notch Preparation for Scorpio PS only Compacting Technique • Assemble the appropriately sized Notch Compactor to the punch handle (Figure 39). • Guide the Notch Compactor into the tracks on the distal face of the Notch Block. The rails on the sides of the cutting edge fit into the tracks on the inside walls of the block.

Figure 39

Notch Compactor

Figure 40

Figure 41

22

A.R. Technique

• Using a Mallet, impact the Compactor until it reaches the end-stop and is fully seated in the No tch Bl ock ( Fi g u re 40). Rem ove the Compactor from the tracks with a Slaphammer if necessary (Figure 41).

Femoral Preparation Notch Preparation for Scorpio PS only Option 2:

Figure 42

Saw Technique

Modular notch saw guide

• Guide the pegs of the appropriately sized Notch Saw Guide into the anterior holes on the Notch Block (Figure 42). • Use a narrow saw blade, osteotome, or double-edged reciprocating saw blade and the Notch Saw Guide as a guide to saw or cut distally through the entire depth of the intercondylar notch (Figure 43). • Using the inner walls of the Un iversal No tch Guide as a saw guide, lay the saw blade flat against the cut ting guide and saw on it thro u gh the intercondylar notch both medially and laterally until the cut is complete (Figure 44).

NOTE: Even if the saw technique is used, you must still perform the Notch Co m pa cting step to confirm that enough bone was removed to accommodate the cam and post.

Figure 43

Figure 44

A.R. Technique

23

Notch Preparation for Scorpio PS only Compacting Technique • Assemble the appropriately sized Notch Compactor to the punch handle (Figure 45). • Guide the Notch Compactor into the tracks on the distal face of the Notch Block. The rails on the sides of the cutting edge fit into the tracks on the inside walls of the block.

Figure 45

Notch Compactor

Figure 46

Figure 47

24

A.R. Technique

• Using a Mallet, impact the Compactor until it reaches the end-stop and is fully seated in the No tch Bl ock ( Fi g u re 46). Rem ove the Compactor from the tracks with a Slaphammer if necessary (Figure 47).

Tibial Preparation Option 1: Extramedullary Technique With the knee flexed, place the External Tibial Alignment Guide on the tibial shaft. Place the spring-loaded clamp around the distal tibia just above the malleoli. Place the head of the instrument over the tibial eminence. There should be a finger’s breadth clearance between the proximal shaft of the alignment guide and the anterior cortex when the head is positioned properly. Centre the proximal fixation pins over the tibial eminence and tap in the most posterior pin first to fix the anterior/posterior location of the head. Rotation is now adjusted, and then set, by anchoring the second pin. Tighten the vertical screw to secure the proximal shaft of the guide (Figure 48).

Axial alignment is achieved when the vertical shaft of the instrument parallels the long axis of the tibia in both the anterior/posterior and medial / lateral vi ews . Use the anteri or / po s teri or and medial / l a teral ad ju s tm ent thu m b s c rews to fac i l i t a te alignment (Figures 49 and 50).

Fixation Pin

Figure 48

Proximal Shaft

Figure 49

External Tibial Alignment Guide

Figure 50


Vertical Screw medial/lateral Adjustment Screw

anterior/posterior Adjustment Screw

25

Tibial Preparation Extramedullary Technique Landmarks often used to obtain correct axial alignment and rotation include: 1. Tibial Tubercle - The alignment rod usually lies over the medial third of the tibial tubercle. 2. Second Metatarsal - The second metatarsal generally is in line with the centre of the ankle (Figure 51). Once axial alignment is established, tighten the anterior/ po s teri or and med i a l / l a teral ad ju s tm ent thu m b s c rews (Figure 52).

Figure 52 Figure 51

Rotational Alignment

Distal Alignment

anterior/ posterior Adjustment Screw

medial/lateral Adjustment Screw

26

Extramedullary Technique Tibial Resection Level

Figure 54

The Xcelerate System offers Right and Left, 0° and 5° Tibial Resection Guides. Assemble the tibial stylus onto the Tibial Resection Guide by depressing the button on the top of the Tibial Stylus, inserting the stylus into either the medial or lateral holes on the top of the Tibial Resection Guide and releasing the button to lock the stylus into place (Figure 53). Attach the Tibial Resection Guide/Tibial Stylus assembly to the External Tibial Alignment Guide by sliding it over the top of the proximal shaft, ad ju s ting the stylus to reference the desired point on the tibial plateau (Figure 54). ™


Proximal Shaft

Figure 53

Locking Button

Tibial Stylus

Tibial Resection Guide

27

Tibial Preparation Extramedullary Technique The Xcelerate™ System offers two Tibial styli each having two resection levels; 2mm and 8mm.

Figure 55

Figure 56

2mm Resection

8mm Resection

Tibial Stylus

28

The settings allow for a corresponding resection of bone below the point of the stylus (i.e. the 2mm setting allows for a 2mm resection below the point of the stylus). (Figures 55 and 56). Once the resection level is established, tighten the t hu m b s c rew on the Ti bial Re s ecti on Gu i de . Th e Tibial Stylus is removed by depressing the button and pulling it out.

Tibial Stylus





Proximal Tibial Resection Secure the Tibial Resection Guide to the proximal tibia using two 1/8" drill pins, drilling through the “0” holes. Loosen the thumbscrew that holds the Tibial Resection Guide to the External Tibial Alignment Guide. Loosen the vertical adjustment thumbscrew on the shaft of the alignment guide. Using the Slaphammer, extract the two headed fixation pins on the top of the alignment guide from the proximal tibia. Rem ove the proximal shaft of the align m ent guide by sliding it up thro u gh the top of the re s ecti on guide (Figure 57).

Slide the Tibial Resection Guide posteriorly until it comes in contact with the anterior tibia. Placing a 1/8" drill pin through the “X” pin hole will further secure the resection guide to the tibia. The Al i gn m ent Ha n dle may be used with an Alignment Rod, referencing the same landmarks as outlined previously to verify proper alignment. Re s ect the plateau using a .050" (1.25mm) saw blade (Figure 58). If desired, 2mm or 4mm of additional bone may be resected by repositioning the guide over the pins through the +2 or +4 holes respectively (Figure 59). The Ti bial Re s ecti on Gu i de is rem oved by firs t sliding the guide off the two 1/8" drill pins and then removing the pins with the Pin Puller. NOTE: If the “X” Pin hole is used,this pin must be removed prior to repositioning or removing the Tibial Resection Guide.

Figure 57 Slide Proximal Shaft Up through Resection Guide

Figure 58


Figure 59

Vertical Thumbscrew

29

Tibial Preparation Option 2: Intramedullary Technique IM Rod Placement If the tibial eminence is pronounced, make an initial cut to flatten the tibial plateau and expose an area of cancellous bone. A 5/16" hole is drilled in the location determined by preoperative X-rays (Figure 60).

Attach the predetermined diameter IM Rod (1/4", 3/8", or 5/16") to the T-Handle by depressing the button, inserting the IM Rod fitting, and releasing the button to lock into place. Pre-operative X-ray templating will aid in the determination of the IM Rod diameter. Introduce the IM Rod into the entry hole and gradu a lly adva n ce it down the intramedullary canal (Figure 61). Several steps may be taken to avoid an increase in intra m edu ll a ry pressure: A. Advance the IM Rod slowly B. Ro t a te the IM Rod within the canal du ri n g advancement C. Apply suction to the fitting on the end of the cannulated IM Rod.

Suction Fitting

Figure 60

Figure 61

T-Handle

Diameter Transition Point

IM Rod

30

Tibial Intramedullary Alignment Option The proximal portion of both the 3/8" and 1/4" diameter IM Rods changes to 5/16" in diameter. It is necessary to insert those rods so that the diameter transition point is within the intramedullary canal. The 5/16" diameter IM Rod may be inserted to any depth up to the scribe mark on the proximal shaft. Once the IM Rod is positioned, remove the T-Handle (Figure 62). Intraoperative X-rays may be obtained to confirm accurate position of the rod in the canal. Slide the IM Alignment Guide over the Alignment Rod (Figure 63).

Figure 63 IM Rod Headed Nail

IM Alignment Jig

Figure 62

Diameter Transition Point

31

Tibial Preparation Intramedullary Technique Rotational and Varus/Valgus Alignment

Assemble the appropriate Tibial Resection Guide to the IM Tibial Alignment Guide by sliding the Tibial Resection Guide onto the rail of the alignment guide and ti gh tening the thu m b s c rew on the re s ecti on guide (Figure 65).

With the body of the IM jig resting on the proximal tibia, correct rotational alignment is achieved by rotating the instrument about the IM rod so that the tibial tubercle appears slightly lateral to the vertical mounting bar. The Figure 65 h e aded nail is impacted , fixing ro t a ti onal align m en t (Figure 64).

Figure 64

Headed Nail IM Tibial Alignment Guide

Mounting Bar Tibial Resection Guide

Thumbscrew

32

Attach the alignment handle to the resection guide, and s l i de a long align m ent rod into the align m ent handl e . When correct varus/valgus alignment is attained, the pin should be centred over the ankle (Figure 66).

If varus/valgus adjustment is needed, locking knob “1” is loosened. The mounting bar is pulled toward the surgeon, and the jig is rotated until proper varus/ valgus orientation is achieved (Figure 67). Once the alignment rod is centred over the ankle, the locking knob is securely tightened.

Figure 66 Figure 67

Locking knob “1” Alignment Rod

External Alignment Rod

Alignment Handle

33

Tibial Preparation Intramedullary Technique Flexion/Extension Alignment

Tibial Resection Level

If additional posterior slope is required, loosen locking k n ob “ 2 ” and set the slope . O n ce the correct slope is attained, securely tighten locking knob 2 to set the final position of the jig (Figure 68). Increment markings have been added to the posterior slope adjustment FOR REFERENCE ONLY. Bear in mind that these are reference marks only and not indicative of an exa ct measurement of the posterior slope of the tibial resection. The true slope is dependent on many factors, i n clu d i n g, but not limited to, ti bial anatomy, t h e placement of the IM Rod, the position of the cutting block from the anterior portion of the tibia, etc.

The Xcelerate™ System offers Right and Left, 0° and 5° Tibial Resection Guides.

Figure 68

Assemble the Tibial Stylus onto the Tibial Resection Guide by depressing the button on the top of the Ti bial Stylu s , i n s erting the stylus into ei t h er the m edial or lateral hole on the top of the Ti bi a l Resection Guide, and releasing the button to lock the stylus into place (Figure 69).

Figure 69

Locking Button Knob “2”

Tibial Stylus


Thumbscrew

34

Loosen the thumbscrew and position the Tibial Stylus to reference the desired point on the tibial plateau. Secure the IM Ti bial Al i gn m ent Gu i de to the Ti bial IM Rod by retightening the thumbscrew.

The Xcelerate™ System offers two tibial styli each having two resection levels; 2mm and 8mm. The set ti n gs allow for corresponding resection of bone bel ow the point of the stylus (i.e. the 2mm setting allows for a 2mm resection below the point of the stylus) (Figures 70 and 71).

Figure 70

Figure 71

2mm Resection Level

8mm Resection Level

Locking screw

Locking screw

IM Tibial Alignment Guide

IM Tibial Alignment Guide Tibial Stylus


Tibial Stylus


Thumbscrew Thumbscrew

35

Tibial Preparation Intramedullary Technique Proximal Tibial Resection Once the resection level is established, secure the Tibial Resection Guide to the anterior tibia using the 1/8" drill pins, drilling through the “0” holes. Pinning through the “X” Pin hole will further secure the Tibial Resection Guide to the tibia (Figure 72). Remove the Tibial Stylus by depressing the button and pulling the stylus out. Release the IM Tibial Alignment Guide from the Tibial Re s ecti on Gu i de by loo s ening the thu m b s c rew on the resection guide. Reattach the T-Handle to the IM Rod and extract both the IM Rod and IM Tibial Alignment Guide

together, leaving the Tibial Resection Guide pinned in place. Resect the tibial plateau through the slot in the Tibial Resection Guide. Use of a .050" (1.25mm) sawblade is recommended for an accurate resection (Figure 73). Additional bone may be resected by repositioning the Tibial Resection Guide over the pins in the +2 or +4 holes to resect an additional 2mm or 4mm of bone respectively (Figure 74). The Ti bial Re s ecti on Gu i de is rem oved by firs t sliding the guide off the two 1/8" drill pins and then removing the pins with the Pin Puller. NOTE: If the “X” Pin hole is used, this pin must be removed prior to repositioning or removing the Tibial Resection Guide.

IM Tibial Alignment Guide

Figure 72 Figure 74 Tibial Stylus

1/8” Drill Pin Tibial Resection Guide

Figure 73


36

Option 1 Baseplate Preparation - Fixed Bearing Scorpio® Tibial Component Sizing

Tibial Component Alignment

Maximally flex the knee and deliver the tibia forward. Assemble a Tibial Trial Baseplate onto the Alignment Handle and place it on the resected tibial plateau (Figure 75). Choose the size that best covers the tibial plateau.

Replace the Trial Femoral Component on the femur. Assemble a Tibial Bearing Insert Trial to the Tibial Trial Baseplate by first positioning it posteriorly on the basep l a te and then fully seating it anteri orly ( Fi g u re 76). Reverse the steps to disassem ble the insert trial from the baseplate. Position the assembled insert and baseplate on the tibial plateau and carry out a trial reduction. Assess overall component fit, ligament stability, and joint range of motion. As the joint is taken through flexion and extension, the femoral trial component helps position the tibial baseplate. Final position of the tibial trial is achieved wh en ti bi ofem oral articular con t act is most congruent. This is best assessed when the knee is in extension.

Figure 75

Figure 76

37

Tibial Baseplate Preparation Baseplate Preparation - Fixed Bearing Tibial Component Alignment Overa ll leg align m ent may be assessed at this ti m e . Reattach the Alignment Handle to the trial baseplate and i n s ert two Al i gn m ent Rods into the handl e . The rod s should parallel the mechanical axis of the leg in both the coronal (A/P) and sagittal (M/L) views (Figure 77).

Figure 77 Trial Components in Place

Alignment Rod

Once satisfactory alignment and tibial component ori en t a ti on is ach i eved , m a rk the anteri or ti bi a l cortex in line with the referen ce marks on the anterior border of the trial baseplate (Figure 78). Remove the trial components and disassemble the trial insert from the baseplate. Reposition the Tibial Trial Baseplate aligning the anterior reference marks on the baseplate with the reference marks on the anterior cortex. The baseplate is positioned flush to the anterior tibial cortex. Pin the baseplate to the tibial plateau by placing two short, headed fixation pins through a medial and lateral hole in the baseplate (Figure 79). Pin hole selection is not critical; however, if the anterior holes a re used and the pins are fully seated , the Ti bi a l Be a ring In s ert Trial may be re a s s em bl ed to the pinned baseplate for any subsequent trial reductions.

Figure 78

Baseplate Reference Marks

Alignment Parallels the Mechanical Axis

Marker

Figure 79

Tibial Trial Baseplate

38

Short Headed Pins

Baseplate Preparation - Fixed Bearing Tibial Keel Punching Tibial Punches are identified by keel size (3/5, 7/9, 11/13) and bone prep a ra ti on (“Cement Keel” creates a cem en t mantle around the keel ; “ Press Fit Keel ” c re a tes an interference fit around the keel). The sequence of steps necessary to prepare the tibia for the Deltafit Keel†† may vary depending on the bone quality of the proximal tibia. In relatively soft bone (i.e., rheumatoid) on ly one punching step with the final ti bi a l size/preparation punch may be required. In normal bone, it is recommended that a smaller “Press Fit Keel” punch be used first, followed by the final size/preparation punch. See Appendix 1 (Page 52) - Baseplate Preparation Table

In denser bone, several intermediate punching steps may be required prior to final punching. If sequential punching is undertaken, only “Press Fit Pu n ch e s” should be utilised until the final size is reached. If extremely dense bone is encountered, a 3/8" Guide Bushing may be assem bl ed to the baseplate and a pilot hole dri ll ed pri or to ti bial punching (Figure 80). Assemble the Tibial Punch Tower to the baseplate by placing the tower onto the two small locating pins on top of the baseplate. During the subsequent tibial punching, the tower will maintain correct position of the punches.

Figure 80 Preparation of Pilot Drill Hole with Guide Bushing

39

Tibial Baseplate Preparation Baseplate Preparation - Fixed Bearing Tibial Keel Punching Fit the appropriate Tibial Punch into the Tibial Punch Tower (Figure 81). Handles may be assembled to the tower to aid in maintaining po s i ti on and stabi l i ty of t h e tower/baseplate assembly during punching. A mallet may be used to impact the punch.

Figure 81

Adva n ce the punch until it seats fully on the baseplate (Figure 82). During extraction, take care to avoid toggle or angulation of the punch as this may d i s tort the bone prep a ra ti on . The Quick Rel e a s e Slidehammer connects to the punches for extraction. O n ce the final punch has been seated , ti bi a l preparation is complete (Figure 83).

Figure 82 Tibial Punch is Fully Seated

Tibial Punch

Tibial Punch Tower Quick release handles

Figure 83 Completed Tibial Preparation

40

Scorpio® + Mobile Bearing Knee System Option 2 Baseplate Preparation - Mobile Bearing Overview

Soft Tissue Balancing

The surgical protocol for the Scorpio®+ mobile bearing knee system is intended to be used in conjunction with and as a supplement to the current Scorpio® Xcelerate™ surgical protocol for Primary Total Knee Arthroplasty.

Soft tissue balancing refers to ligament stability and equal joint spacing in flex i on thro u gh to full extension. The Xcelerate™ knee balancer provides the su r geon with an acc u ra te , easy to use met h od of assessing soft tissue balance and measuring flexion and extension gaps. Refer to Xcelerate™ knee balancer technique (Lit No. LXCSS-2) (Figure 84).

Figure 84 Xcelerate™ Knee Balancer

Scorpio®+ Mobile Bearing is not available for use in the USA

41

Xcelerate™ Knee Balancer Detail The Xcelerate™ knee balancer (Figure 85) is assembled by: 1. Assembling Slide Key to Lower Body. 2. Assembling Height Guide and Upper Jaw into Upper Body. 3. Assembling Upper Body Assembly into Lower Body.

Upper Jaw

Figure 85 Xcelerate™ Knee Balancer

Upper Body

Height Guide

Ratchet Release

Lower Body

Slide Key


42

Scorpio® + Mobile Bearing Knee System Tibial Trial Positioning and Reduction Attach the Scorpio®+ Tibial Trial Baseplate Adaptor to the Tibial Trial Baseplate by positioning it anteriorly on the baseplate and then fully seating it (Figure 86) posteriorly. The Scorp i o ®+ Trial In s ert can then be placed on the adaptor plate by centring it over the rotation post on the adaptor and engaging the post with the hole on the distal su rf ace of the trial insert (Figure 87). Reverse the steps above to disassemble the trial insert and adaptor plate from the baseplate.

Figure 86 Tibial Trial Baseplate Adaptor with Trial Baseplate

Position the assembled Trial Insert and Trial Baseplate onto the Tibial plateau and carry out a trial reduction. Assess overall component fit, bone coverage, joint stability and range of motion. While trialing, mark the anterior tibia to indicate the location of the Tibial Trial Baseplate for keel punching. N OT E : If d e s i re d , the Tibial Trial B as eplat e may be pinned to the tibial plateau prior to trial reduction.

Figure 87 Trial Insert


43

Assessment of Fit and Stability Scorpio®+ Mobile Bearing Knee Scorpio®+ Mobile Bearing Trials are used to assess fit of the total knee pro s t h e s i s . O n ce the distal femur and proximal ti bia have been prep a red as out l i n ed in the X cel era te ™ su r gical pro tocol (page 7 and 21), a ll tri a l components should be placed on the prepared femur and tibia (Figure 88) to assess fit, joint stability and range of motion. See Appendix 2 (page53) - Scorpio®+ Interchangeability Chart


44

Figure 88 Trial Components

Scorpio® + Mobile Bearing Knee System Final Tibial Preparation Manually introduce the Tibial Tray onto the prepared tibia and impact until the tray is fully seated (Figure 89). Clear all excess bone cement.

Figure 89 Tibial Tray Impaction

NOTE: It is recommended to apply cement to both the Keel and underside of the tibial tray. NOTE: (Figure 90) After implantation of the Tibial Tray, an additional t rial reduction may be conducted with the use of Scorpio®+ Tibial Trial A daptor Blocks and Trial Inserts.

Figure 90 Scorpio®+ Baseplate with Trial Adaptor Block


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Scorpio®+ Mobile Bearing Insert Assembly Preparation of insert prior to implantation Rem ove the insert from the pack a gi n g. Rem ove and d i s c a rd the oval plate from the insert . ( Fi g u re 91A & Figure 91B). This ensures that the ring for the PS/PCS is prepared prior to assembly onto the tibial tray.

Figure 91 A

Rotate Oval Plate

Oval Plate (discard)

Figure 92 B

Insert

PS/PCS Inserts – Centre the Insert over the rotation post, aligning the post with the hole on the distal surface of the Insert (Figure 93). Gently press the Insert over the post until you feel it "snap" into place. The Insert should sit flush with the baseplate and rotate freely about the post with no resistance. NOTE: Do not use excessive force to seat the Insert onto the baseplate.

CR In s ert – Cen tre the In s ert over the ro t a ti on po s t , aligning the post with the centre of the slot on the distal surface of the Insert (Figure 94). Press the Insert over the post until you feel it "snap" into place. The Insert should ro t a te and tra n s l a te freely abo ut the post with no resistance. NOTE: Do not use excessive force to seat the Insert onto the baseplate.


46

Figure 93 PS/PCS Insert Assembly

Figure 94 CR Insert Assembly

Tibial All-Poly Baseplate Preparation Option 3 Baseplate Preparation - Fixed Bearing All-Poly Tibial Punching To prepare for an All-Poly Tibial Component, the ti bi a must first be prepared with the appropriate size Cement Punch as shown in the Tibial Punching Sequence Chart Appendix 1 (Page 52). NOTE: If sequential punching is undertaken, only “Press Fit Punches” should be utilised until the final size is reached. Remove all instruments from the tibia,including the Tibial Punch, Punch Tower, Trial Baseplate, and Fixation Pins. Set the All-Poly Tibial Punch to the pre-determined keel size (see below) by pulling the side pin out and sliding the stop up or down until the appropriate keel size is reached. Release the side pin to secure the punch position. Impact the All-Poly Tibial Punch into the tibia using the p u n ch slots produ ced from the previous punch i n g sequence as a guide (Figure 95).

Con ti nue impacti on until the stop con t acts the proximal tibia. It is important that the All-Poly Tibial Punch be held straight during impaction. Once the punch has been seated, remove it with a m a ll et or the Quick Release Sl a ph a m m er. Th e resected and punched surfaces are prepared for bone cement in the usual fashion. After the preferred cementing technique has been performed, place the All-Poly Tibial Component into the prepared tibia. Seating is accomplished by first positioning and partially seating the component by h a n d , fo ll owed by final seating with the All - Po ly Ti bial Im p actor ( Fi g u re 96). Af ter the cem ent is cured, the knee is thoroughly cleaned and lavaged.

All-poly Tibial Impactor

Figure 95

Figure 96 All-poly Tibial Punch

Side Pin Stop

All-poly Tibial Component

47

Patellar Preparation

Remove all osteophytes and synovial insertions around the p a tell a , and measu re thickness using a caliper. Af ter determining the depth of the cut with a caliper, fix the s tylus in the appropri a te slot to the patellar re s ecti on guide, and capture the patella between the jaws of the saw guide. Using a .050" non-offset sawblade, resect the patella (Figure 97).

Figure 97

Centre the chosen patellar drill guide over the patella with the handle perpendicular to the troch l e a r groove . D ri ll three fixati on holes w ith the appropriate stepped drill (Figure 98). Prepare the resected bone surfaces for bone cement a pp l i c a ti on . See page 51 for cem en ting with the Patellar Clamp.

Figure 98 Stepped Drill Patellar Resection Guide 12inch 5 0r 7

Stylus

48

Drill Guide

Implantation Tibial Component If ti bial fixati on is to be augm en ted by bone screws , remove the polyethylene plugs in the tibial tray screw holes prior to implantation (Figure 99). Assemble the Tibial Component Impactor/Extractor to the implant. To assemble, retract the slide rod levers and insert the “feet” into the central hole in the tibial tray. Release the levers and ti gh ten the knu rl ed thumbscrew by hand to s ec u rely en ga ge the impactor / ex tractor to the implant (Figure 100). Figure 99

Introduce the tibial tray into the prepared tibia and impact it until the tray is fully seated (Figure 101). Clear all excess bone cem ent while maintaining position of the implant.

Figure 101 Tibial Tray Implantation

Figure 100 Retract Slide Levers to Engage Feet in Tibial Tray

Thumbscrew Slide Lever

49

Tibial Bearing Insert Assembly

Implantation of Femoral Component

Prior to assembly of the prosthetic UHMWPE bearing insert, the trial insert may be placed in the tibial tray to once more assess joint stability and range of motion. To assemble the prosthetic bearing insert, distract the joint and angle the insert posteriorly into the tray. The posterior lips of the bearing insert must fit beneath the lips on the interior, posterior tray wall. Snap the insert in place anteriorly ( Fi g u re 102). Hand pressure or a light tap with a mallet is required. The tibial bearing insert is fully seated once the metal retaining wire locks under the barbs on the anterior, interior surface of the tray wall.

Assemble the appropriate size of left or right femoral implant onto the Femoral Impactor/Extractor in the same manner as the femoral trial. Place the implant on the prep a red femur and impact it until fully seated (Figure 103). The Impactor/Extractor aids in maintaining accurate position of the implant during implantation.

Figure 103

Figure 102 Femoral Impactor

Tibial bearing Insert

FIRST ENGAGE POSTERIORLY, THEN SNAP INTO PLACE ANTERIORLY

50

Closing Implantation of the Patellar Component Closure The back surface of the implant (including the pocket) and the cut surface of the patella are covered with a layer of cem en t . Cem ent should be interd i gi t a ted into the fixation holes on the cut patella and the pocket on the back of the all-plastic Patellae Components. The patellar clamp locks in place while the cem en t hardens (Figure 104).

After cement polymerisation, thoroughly irrigate the j oint and place su cti on dra i n s . Hemostasis is achieved after deflation of the tourniquet. Close soft tissues in the normal layered fashion.

Figure 104

Patellar Clamp

51

Tibial Baseplate Preparation Appendix 1

TIBIAL PUNCHING SEQUENCE IMPLANT SIZE

CEMENT KEEL

ALL-POLYETHYLENE IMPLANT

3

PRESS-FIT #3/#5

PRESS-FIT #3/#5 CEMENT #3/#5

PRESS-FIT #3/#5 CEMENT #3/#5 ALL-POLY #3/#5

5

PRESS-FIT #3/#5

PRESS-FIT #3/#5 CEMENT #3/#5

PRESS-FIT #3/#5 CEMENT #3/#5 ALL-POLY #3/#5

7

PRESS-FIT #3/#5 PRESS-FIT #7/#9

PRESS-FIT #3/#5 PRESS-FIT #7/#9 CEMENT #7/#9

PRESS-FIT #3/#5 PRESS-FIT #7/#9 CEMENT #7/#9 ALL-POLY #7/#9

9

PRESS-FIT #3/#5 PRESS-FIT #7/#9

PRESS-FIT #3/#5 PRESS-FIT #7/#9 CEMENT #7/#9

PRESS-FIT #3/#5 PRESS-FIT #7/#9 CEMENT #7/#9 ALL-POLY #7/#9

PRESS-FIT #3/#5 PRESS-FIT #7/#9 PRESS-FIT #11/#13

PRESS-FIT #3/#5 PRESS-FIT #7/#9 PRESS-FIT #11/#13 CEMENT #11/#13

PRESS-FIT #3/#5 PRESS-FIT #7/#9 PRESS-FIT #11/#13 CEMENT #11/#13 ALL-POLY #11/#13

PRESS-FIT #3/#5 PRESS-FIT #7/#9 PRESS-FIT #11/#13

PRESS-FIT #3/#5 PRESS-FIT #7/#9 PRESS-FIT #11/#13 CEMENT #11/#13

PRESS-FIT #3/#5 PRESS-FIT #7/#9 PRESS-FIT #11/#13 CEMENT #11/#13 ALL-POLY #11/#13

11

13

52

PRESS-FIT KEEL

Scorpio®+ Mobile Bearing Knee System Appendix 2 Scorpio®+ Component Size Interchangeability With the Scorpio®+ Mobile Bearing Knee system, femoral component and insert size must be matched, while Tibial trays can be interchanged one size up and one size down, thus allowing for intraoperative flexibility.

Femur/Insert Size 3

5

7

9

11

13

3 5 7 9 11 13


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Raheen Business Park Limerick Ireland t: +353 61 498200 f: +353 61 498281 www.stryker.com

The information presented in this brochure is intended to demonstrate a Stryker product. Always refer to the package insert, product label and/or user instructions before using any Stryker product. Products may not be available in all markets. Product availability is subject to the regulatory or medical practices that govern individual markets. Please contact your Stryker representative if you have questions about the availability of Stryker products in your area. Products referenced with ™ designation are trademarks of Stryker. Products referenced with ® designation are registered trademarks of Stryker. Literature Number: 713210LI NS/CRS 1k 03/04 Copyright © 2004 Stryker Printed in Ireland