Stryker Scorpio TS User Manual

Scorpio®TS
Single Axis Revision
Knee System
Orthopaedics
Scorpio TS Trial Cutting Guide Surgical Protocol
Scorpio®TS
Single Axis Revision
Knee System
Orthopaedics
Scorpio TS
Trial Cutting Guide Surgical Protocol
Acknowledgements
Stryker Orthopaedics would like to thank Dr. Masini for his help in developing the Scorpio Trial Cutting Guide.
Michael A. Masini, MD
Ann Arbor Bone and Joint Surgery St. Joseph Mercy Hospital Ann Arbor, MI
Clinical Instructor in Orthopaedic Surgery University of Michigan Ann Arbor, MI
Introduction
This surgical protocol is a supplement to the Scorpio Total Stabilizer Revision Knee System Surgical Protocol (Lit No. LSTS/ST).
The Scorpio Trial Cutting Guide is an intramedullary based instrumentation system focused on the restoration of the joint line and proper flexion-extension gap assessment.
1
Tibial and Femoral Canal Preparation
Scorpio Trial Cutting Guide
Tibial Preparation
Prepare the tibia following the Scorpio Total Stabilizer Revision Knee System Surgical Protocol (Lit. No. LSTS/ST, pages 1- 5). If an offset is needed, use the tibial offset reamer to prepare for the tibial offset. Insert the assembled trial into the tibia (Figure 1 and Figure 2).
Note: The Scorpio Trial Cutting Guide (TCG) is designed for use with its own mating tibial insert trial. The trial insert does not have a post to allow for more accurate assessment of the ligaments during surgery.
Femoral Canal Preparation
Prepare the femoral canal to accept a stem as described in the Scorpio Total Stabilizer Revision Knee System Surgical Protocol (Lit. No. LSTS/ST, page 5). If an offset is needed, use the femoral offset reamer to prepare for the femoral offset (Lit. No. LSTS/ST, page 9) (Figure 3).
Figure 1 Tibial Canal Preparation Figure 2 Tibial Trial Assembly and
Insertion
Femoral Offset Reamer
8200-0095
Reamer Depth Stop
8200-0047 80mm stem with offset 8200-0048 155mm stem with offset
2
Figure 3 Femoral Canal Preparation
Tibial Boss/Offset Reamer
8200-0015
Command T-Handle
6266-5-401
IM Reamers
6633-9-408 8mm 6633-9-409 9mm 6633-9-410 10mm 6633-9-411 11mm 6633-9-412 12mm 6633-9-413 13mm 6633-9-414 14mm 6633-9-415 15mm 6633-9-416 16mm 6633-9-417 17mm 6633-9-418 18mm 6633-9-419 19mm 6633-9-420 20mm 6633-9-421 21mm 6633-9-422 22mm 6633-9-423 23mm
Femoral/Tibial Trial Selection
Scorpio Trial Cutting Guide
Femoral/Tibial Trial Selection
Select the appropriate size femoral trial cutting guide, offset adapter, and corresponding tibial insert trial (Table 1).
Appropriate sizing can be achieved through the use of:
• Previous operative notes
• Size of the original implant removed
• X-ray templates
Femoral Cutting Guide
Table 1 Trial Cutting Guide Instrument Sizes
Category Sizes
Femoral Cutting Guides 3, 5, 7, 9, 11, 13
Offset Adapter 0mm, 2mm, 4mm, 6mm, 8mm
Tibial Insert Trial Sizes 3, 5, 7, 9, 11, 13
Tibial Insert Trial Thickness 10mm, 12mm, 14mm, 16mm , 18mm, 21mm, 24mm
The Scorpio Trial Cutting Guide (TCG) can be assembled for either a left or right knee. Assemble the offset adapter into the housing of the TCG so the offset adapter is pointing to the appropriate left or right orientation (Figure 4).
Figure 4 Trial Cutting Guide in “Right” Orientation
Trial Cutting Guide
8200-5003 8200-5005 8200-5007 8200-5009 8200-5011 8200-5013
3
Femoral/Tibial Trial Selection (continued)
Scorpio Trial Cutting Guide
Assembly
Assemble the trial cutting guide, offset adapter, and appropriate size trial stem as shown (Figure 5).
A neutral offset adapter may be used initially to construct the trial cutting guide assembly until the need for a femoral offset is determined.
First, assemble the trial stem to the offset adapter, then assemble the offset adapter into the Trial Cutting Guide housing and secure the anterior set screw. Once “finger tight” pressure is achieved, rotate counterclockwise 1/2 turn to allow the offset adapter to rotate freely. The anterior set screw will be fully secured after the appropriate offset and rotation is determined (Figure 6).
Note: Rotating counterclockwise 1/2 turn will allow the offset adapter to rotate freely without disassembling from the Trial Cutting Guide housing. Rotating counterclockwise more than 1/2 turn will cause the offset adapter to fall out of the Trial Cutting Guide housing.
Trial Stem
Offset Adapter
Figure 6 Set Screw Assembly
Set Screw
Trial Cutting Guide Housing
Trial Cutting Guide
Figure 5 Trial Cutting Guide Assembly
Torx Screwdriver
8200-5110
4
Tibial Insert Trial
T72-7-XXYY XX = 03, 05, 07, 09, 11 YY = 10, 12, 14, 16, 18, 21, 24
Offset Adapter
8200-5100 8200-5102 8200-5104 8200-5106 8200-5108
Trial Cutting Guide Orientation
Scorpio Trial Cutting Guide
Note: Femoral chamfer cuts cannot be made with the TCG. However, if bone loss is minimal and it is determined that chamfer cuts are required, the Scorpio Total Stabilizer (TS) All-In-One Cutting Block may be used to make chamfer cuts (Lit. No. LSTS/ST, Page 8).
Joint Line Restoration
Insert the TCG into the femoral canal (Figure 7) and align the TCG medial epicondyle (ME) scribe line reference mark with the medial epicondyle (Figure 8). The ME scribe line is 28mm from the distal surface of the TCG. When the ME scribe line is in line with the medial epicondyle, the distal surface of the TCG will be approximately located at the joint line. (The joint line can also be estimated using pre-operative radiographs and anatomic landmarks.)
Figure 7 TCG Femoral Canal Insertion
ME Scribe
Medial
Figure 8 Joint Line Restoration to Medial Epicondyle
Place an initial fixation pin in the middle of the medial slot on the TCG (Figure 9 and Figure 10). Pinning the medial slot will fix the proximal/distal position while allowing for slight internal and external rotation of the TCG.
1/8" Headless Pins
7650-1038
Figure 9 Initial Fixation Pin Insertion Figure 10 Initial Fixation Pin –
Extension
Joint Line Scale
8200-0065
5
Trial Cutting Guide Orientation (continued)
Scorpio Trial Cutting Guide
Femoral Offsetting
There are several ways to determine the proper femoral offset required.
1) Start with a neutral offset and measure or estimate the distance from the inferior surface of the anterior flange of the TCG to the anterior femur (Figure 11) or,
2) Line up the femoral sizing “C” templates with the trial stem and measure or estimate the distance from the anterior femur to the inferior surface of the anterior flange of the TCG.
Note: A 4mm offset is typical for many revision scenarios, and if an A/P offset is not necessary, the offset adapter may be used to displace the femur medially or laterally.
Note: When adjusting the offset of the TCG, the entire offset adapter and stem construct will be rotating.
Figure 11 Offset Measuring Figure 12 Trial Cutting Guide
Offsetting
Anterior Set Screw
To adjust the offset, insert the hex driver into the distal face of the offset adapter and rotate (Figure 12). After final offset position has been determined, tighten the anterior set screw to secure the offset position on the TCG (Figure 6, page 4).
If an offset is required, record the final position of the offset by reading the location of the hash mark on the offset adapter relative to the clock face on the TCG. The clock recording will be required when assembling the implant. If an offset is not required, use the 0 adapter (Figure 13).
Note: The numerical clock on the TCG is a mirror image of the clock face markings on the femoral trial and final implant (Figure 14 and Figure 14a).
Figure 13 Offset Reading Figure 14 Trial Cutting Guide and
Implant/Trial Clock Face
Figure 14A Enlarged View of Clock Face (0=Posterior Offset)
Femoral Sizing Template
8200-0096 #3/5 8200-0097 #7/9 8200-0098 #11/13
6
Trial Cutting Guide Orientation (continued)
Scorpio Trial Cutting Guide
Preliminary Trial Assessment
With the joint line restored and the appropriate offset determined, a preliminary trial assessment should be conducted with the trial tibial components in place (Figure 15).
Select the appropriate trial tibial insert and place it onto the trial tibia. Select the insert that provides varus/valgus stability in full extension (Figure 16).
Figure 15 Preliminary Trial Assessment
Figure 16 Varus/Valgus Stability Check at Full Extension
7
Trial Cutting Guide Orientation (continued)
Scorpio Trial Cutting Guide
Rotation
With the knee flexed at 90°, appropriate external rotation can be set by positioning the TCG on the tibial trial insert so that it is seated with no varus/valgus tilt. The transepicondylar axis or Whiteside’s axis can be used to estimate rotation as well.
A second headless fixation pin should then be placed in the TCG’s anterior pin hole to fix the TCG position once rotation has been established (Figure 17). Place as many pins as necessary to securely fix the TCG on the distal femur.
Note: Headless pins may now be replaced with short headed fixation pins to facilitate joint reduction.
Note: The TCG trial inserts do not have a post. This allows for a more accurate assessment of the ligaments during trialing.
Figure 17 Second Fixation Pin – Rotation
Headed Fixation Pin
7650-1136 1” Headed Pin 7650-1137 3” Headed Pin
8
Trial Cutting Guide Orientation (continued)
Scorpio Trial Cutting Guide
Trial Assessment
Once the TCG is fixed to the femur, a trial reduction may be conducted. Reduce the extensor mechanism and patella. The inferior pole of the patella should rest approximately 14mm above the joint line with the knee in 90° of flexion unless patella baja or patella alta was present pre-operatively. Tracking of the patella can then be assessed (Figure 18).
Note: A suture or towel clip may be used to facilitate reduction and trial assessment (Figure 19).
It should be noted that the flexion gap often feels “too loose” in the revision situation even when the appropriately sized femoral implant is positioned at the joint line. Using the TCG gives the surgeon the unique opportunity to upsize the femoral component and offset the next size femur to selectively fill the flexion gap that feels “too loose.” However, if upsizing results in poor tracking and “overstuffing of the joint”, the surgeon need only return to the previous size TCG and offset.
Note: A full evaluation of stability and range of motion can be performed before making any resections on the distal femur. Adjustment of the implant position and size is possible before making any femoral bone cuts.
Figure 18 Preliminary Trial Reduction
Suture
Figure 19 Preliminary Trial Reduction With Suture
9
Femoral bone Cuts
Scorpio Trial Cutting Guide
Note: A Stryker 152 saw blade (narrow-thick) or a reciprocating saw blade are recommended for augment cuts and the box cut.
Augment Cuts
With the TCG properly positioned, visually determine the appropriate posterior and distal resections required (Figure 20 and Figure 21). A blade runner may be used to assess the level of resection if necessary. The appropriate cut is selected by resting the blade on the surface of the TCG apertures that will provide a clean up cut.
Note: If an augment cannot effectively “fill the gap,” i.e., deficiencies greater than 15mm distally or 10mm posteriorly, a bone graft may be required (Figure 22).
Figure 20 Posterior Femoral Cuts Figure 21 Distal Femoral Cuts
Box Cut
When making the box cut, cut along the outer sides of the box guide and cut completely through the femur (Figure 23 and Figure 24). The posterior portion of the proximal box cannot be completed due to the presence of the stem. Complete the proximal posterior box cut after the TCG has been removed using the initial resection as the guide.
Note: The sides of the box may be completed with a distal approach (Figure 25) in addition to the anterior approach.
Figure 22 Bone Graft Figure 23 Box Cut – Side Walls
10
Figure 25 Box Cut – Distal ApproachFigure 24 Box Cut – Proximal Wall
Final Trial Assessment
Scorpio Trial Cutting Guide
A final trial assessment should be conducted with the Scorpio TS trial femoral components to verify the accuracy of the cuts and that the offset has been properly recreated (Figure 26).
See the Scorpio Total Revision Knee System Surgical Protocol (Lit. No. LSTS/ST, page 10) for details on trial assembly and trial reduction.
Figure 26 Final Trial Assessment
11
Quick Pictorial Surgical Technique Reference
Scorpio Trial Cutting Guide
1.
Tibial Canal
Preparation
2.
Femoral
Canal
Preparation
3.
Trial
Cutting
Guide
Assembly
Trial Stem
Offset Adapter
Set Screw
Trial Cutting Guide
4.
TCG
Femoral
Canal
Insertion
5.
Joint Line
Restoration
to Medial
Epicondyle
6.
Initial
Fixation Pin
Insertion
12
8.
Preliminary
Trial
Assessment
9.
2nd
Fixation Pin –
External Rotation
Alignment
10.
Preliminary
Trial
Reduction
7.
Trial
Cutting
Guide
Offsetting
Quick Pictorial Surgical Technique Reference
11.
Posterior
Femoral Cuts
Scorpio
®
Trial Cutting Guide
12.
Distal
Femoral Cuts
14.
Final Trial
Assessment
13.
Box Cut
1413
Sizing Information
Scorpio Trial Cutting Guide
Scorpio TS Femoral Component Specifications
Size A/P-Med A/P-Lat M/L A/P Height Box Width Width Height*
(mm) (mm) (mm) (mm) (mm) (mm) (mm) (mm)
#3 52 54 56 35 20 17 20 42
#5 56 58 61 39 20 17 22 42
#7 60 62 66 44 23 19 24 46
#9 66 68 71 49 23 19 26 46
#11 72 72 76 53 25 21 28 48
#13 74 76 81 58 25 21 30 48
*With end cap
Resected Box Intercondylar Condylar Stem
77-4003 77-4005 77-4007 77-4009 77-4011
72-4-03xx 72-4-05xx
72-4-03xx 72-4-05xx
Femoral
Components
**Scorpio®PS Inserts may be used.
Scorpio TS Tibial Tray Specifications
A/P M/L Stem Boss
Size
(mm) (mm) Length* (mm)
3 40 61 35
5 44 66 35
7 47 71 37
9 51 77 37
11 54 82 43
13 58 88 43
*With end cap
Tibial Baseplates**
72-4-57xx Crossover
72-4-75xx Crossover
72-4-07xx 72-4-09xx
72-4-07xx 72-4-09xx
Scorpio TS Tibial Insert Specifications
Size
3 40 61 23 16
5 44 66 23 16 7F/5T 44 66 27 18 5F/7T 47 71 23 16
7 47 71 27 18
9 51 77 27 18
11F/9T 51 77 29 20 9F/11T 54 82 27 18
11 54 82 29 20
72-4-91xx
Crossover
72-4-19xx Crossover
A/P M/L Height Width
(mm) (mm) (mm) (mm)
72-4-11xx
72-4-11xx
Post Post
A surgeon must always rely on his or her own professional clinical judgment when deciding whether to use a particular product when treating a particular patient. Stryker does not dispense medical advice and recommends that surgeons be trained in the use of any particular product before using it in surgery.
The information presented is intended to demonstrate the breadth of Stryker product offerings. A surgeon must always refer to the package insert, product label and/or instructions for use before using any Stryker product. Products may not be available in all markets because product availability is subject to the regulatory and/or medical practices in individual markets. Please contact your Stryker representative if you have questions about the availability of Stryker products in your area.
Stryker Corporation or its divisions or other corporate affiliated entities own, use or have applied for the following trademarks or service marks: Scorpio, Stryker. All other trademarks are trademarks of their respective owners or holders.
Literature Number: LSPK34 Rev. 2 MS/GS 06/11
Copyright © Stryker 2011 Printed in USA.
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