NAVIO Surgical System Surgical Technique for use with the JOURNEY™ II BCS and JOURNEY™ II CR Procedure Guide Rev B Nov 2016

NAVIO™ Surgical System Surgical Technique for use with the JOURNEY™ II BCS and JOURNEY™ II CR Smith & Nephew

500081, Rev B Issue Date: 2016-11-16

The following technique is for informational and educational purposes only. It is not intended to serve as medical advice. It is the responsibility of treating physicians to determine and utilize the appropriate products and techniques according to their own clinical judgment for each of their patients. For more information on the NAVIO™ Surgical System, including its indications for use, contraindications, and product safety information, please refer to the product’s label and the Instructions for Use packaged with the product.

© Smith & Nephew 2016. Patents: 6,757,582; 5,880,976; 6,205,411; 6,711,431; 8,961,563 B2.

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Introduction This procedure guide provides an overview of the recommended surgical technique for using the NAVIO™ surgical system technology with the JOURNEY™ II CR (Cruciate Retaining) and JOURNEY™ II BCS (Bi-Cruciate Stabilized) Knee System. Smith & Nephew recommends that users review this guide prior to performing total knee arthroplasty utilizing the NAVIO system. This guide should be used in conjunction with, not replacing, the information contained within the NAVIO™ Surgical System for Total Knee Arthroplasty User’s Manual that accompanied the purchase of the NAVIO surgical system. Additional information on the JOURNEY II CR (Cruciate Retaining) and BCS (Bi-Cruciate Stabilized) knee systems and manual instrumentation technique can be found in the product labeling and in the Surgical Technique for the JOURNEY™ II TKA Total Knee System from Smith & Nephew.

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Contents Intended Use, Indications, Contraindications... 5 Design Rational/Surgical Planning Rational... 6 NAVIO Surgical System Overview... 7 Navio Instrument Trays... 8 Positioning the System... 9 1. System and Patient Setup... 10 2. Bone Tracking Hardware ... 12 3. Surgical Preferences... 14 4. Registration ... 17 5. Ligament Balancing... 25 6. Implant Planning... 26 7. Implant Planning - Soft Tissue Balancing ... 32 8. Bone Cutting ... 36 9. Trial Reduction... 44 10. Cement and Close ... 45 Recovery Procedure Guidelines... 46 Notes... 47 Manufacturer Contact Information... 48

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Intended Use The NAVIO surgical system is intended to assist the surgeon in providing software-defined spatial boundaries for orientation and reference information to anatomical structures during orthopedic procedures.

Indications for Use The NAVIO™ surgical system is indicated for use in surgical knee procedures, in which the use of stereotactic surgery may be appropriate, and where reference to rigid anatomical bony structures can be determined. These procedures include unicondylar knee replacement (UKR), patellofemoral arthroplasty (PFA), and total knee arthroplasty (TKA). The NAVIO surgical system is indicated for use with cemented implants only.

Contraindications The NAVIO™ surgical system is not intended to be used on children, pregnant women, patients who have mental or neuromuscular disorders that do not allow control of the knee joint, morbidly obese patents, or any other patients contraindicated for unicondylar knee replacement surgery, patellofemoral knee replacement surgery, or total knee replacement surgery. Consult the JOURNEY™ II Total Knee System labeling for its full intended use, indications and contraindications.

Warning: Please reference the implant manufacturer’s instructions for use and recommendations for the compatibility of implant system combinations.

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JOURNEY™ II TKA Total Knee Design Rationale The goal of the JOURNEY™ II Total Knee System is to enable a higher level of function for total knee replacement patients – to not only relieve pain, but to help them regain their active lifestyles (Figure 1). Function, motion and durability are achieved through the unique features of the JOURNEY II Total Knee System–anatomic alignment, kinematics and advanced bearings. Indications for use include rheumatoid arthritis, post-traumatic arthritis, osteoarthritis or degenerative arthritis, failed osteotomies, or unicompartmental replacement. This system is designed for use in patients in primary total knee replacement surgery, where the anterior and posterior cruciate ligaments are incompetent and the collateral ligaments remain intact. To replicate normal knee motion, the JOURNEY II CR prosthesis provides more mobility in the lateral compartment than other total knee systems. For patients that present with significant varus or valgus deformities (> 15º), morbid obesity or deficient posterior cruciate ligament, consider whether additional implant constraint is more appropriate.

Surgical Planning Rationale  Consult the JOURNEY™ II Total Knee System Surgical Technique for more details on the surgical planning rationale for the implant components.

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Figure 1

NAVIO™ Surgical System Overview The NAVIO™ Surgical System is a surgical planning, navigation and intraoperative visualization system combined with a handheld smart instrument for bone sculpting. The optical tracking camera communicates the relative position of the handpiece (cutting tool), the femur, and the tibia (via rigid tracker arrays) to the computer cart, which runs algorithms that control the handpiece (Figure 2). The patient’s bone is prepared according to an intra-operative plan that combines soft-tissue and anatomic information to control bone removal and prepare for rigid fixation of the NAVIO reusable cut guides, which include the distal femur cut guide and tibia cut guide, according to the component placement plan. NAVIO Total Knee surgery can be broken up into the following stages. For clarity, this technique guide is separated into sequential sections:

Figure 2

1. System and Patient Setup 2. Bone Tracking Hardware 3. Surgical Preferences 4. Registration 5. Ligament Balancing 6. Implant Planning 7. Implant Planning - Soft Tissue Balancing 8. Bone Cutting 9. Trial Reduction 10. Cementing Final Components & Closing The implant planning and bone cutting stages are customizable as per the workflow preferences selected by the user, highlighted in the Surgical Preferences section (Section 3) of this guide.

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NAVIO™ Instrument tray Small Parts Sterilization Case Handpiece Tracker Frame

Femur Tracker Frame Handpiece

The NAVIO Instrument tray consists of a two-level tray that contains the required instrumentation for a NAVIO-assisted surgery, including a roboticcontrolled NAVIO handpiece, Anspach power drill, interchangeable guards, tracker frames, bone tracker hardware and clamps, a Z knee retractor, and a rasp that has flat and rounded rasping surfaces (Figure 3a). Tibia Tracker Frame

Rasp Point Probe

Long Attachment

Tissue Protector

Metal Guards

Tracker Clamps (2)

T-Wrench Anspach Surgical Drill Z Knee Retractor Bone Screw Driver Figure 3a.

NAVIO™ Total Knee Instrument tray The NAVIO™ Total Knee Instrument tray is a single-level tray that contains the required instrumentation for a NAVIO-assisted total knee arthroplasty (Figure 3b). The tray includes reusable femur cut guides (small, medium, and large), reusable tibia cut guide components (small, medium, and large for left and right configurations), a reusable femur cut adapter, implant-specific femur drill guide and a plane visualization tool. If any of the equipment breaks or becomes soiled during the surgery, backup sterile NAVIO trays are on-site and can be unwrapped to replace a broken or dropped tool.

Right Tibia Cut Guides Femur Distal Cut Guides (Small, Medium, Large) (Small, Medium, Large) Left Tibia Cut Guides (Small, Medium, Large)

Femur Stabilizers (Small, Medium, Large) Femur Cut Adapter Figure 3b.

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Plane Visualization Tool JOURNEY™ II Femur Drill Guide

Positioning the System Position the NAVIO™ computer cart so that the surgeon can clearly see and easily operate the graphical user interface at all times. The computer cart should be positioned on the opposite side of the leg to be operated. The camera stand should be placed approximately 1.5 m from the surgical site and 1.8 m - 2.1 m high, also on the opposite side of the leg to be operated. (Figure 4a) Position the operative knee into 90º flexion. Use the laser pointer integrated into the faceplate of the camera head to direct the laser beam at the knee joint to be operated. The camera position may be adjusted at any point during the operation to meet the needs of the surgeon, except during determination of the hip center.

Left-knee OR Setup (above)

Guidance for camera positioning is provided on the Camera Orientation Adjustment screen of the NAVIO intraoperative application. Once the system is positioned and the patient has been properly draped and prepped, the sterile drape should be applied to the monitor, according to the instructions for use provided by the monitor drape manufacturer (Figure 5). An additional drape may be used to cover the computer cart. Once properly sterile-draped, the computer cart is backed up to the operating table and the monitor is rotated to cantilever over the patient, aimed diagonally at the surgeon’s line of sight (Figure 4a).

Right-knee OR Setup (above) Figure 4a.

Additional Notes If the sterile reflective markers become soiled and the marker visibility is compromised (markers not visible in the Camera Orientation Adjustment screen or there is flickering of the marker visibility indicator), replace the markers on the affected tracker. Use clean, sterile gloves to handle the markers. Support the tracker frame behind the marker attachment point. Avoid transferring force to the entire tracker frame. After handpiece calibration/homing is completed, separate the handpiece from the point probe. Hold the point probe close to the back for easier detachment (Figure 4b). Figure 4b.

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1 System and Patient Setup Preparing the System and Tool The surgical team will set-up the NAVIO™ system to utilize the integrated irrigation system (refer to the Irrigation Tubing Assembly section in the NAVIO™ Surgical System for Total Knee Arthroplasty User’s Manual), which will provide continuous irrigation throughout bone removal. Be sure to keep irrigation tubing clips clear during attachment of the point probe. The surgical team will assemble the NAVIO handpiece according to the operating surgeon’s preference. The configuration found to be most conducive to bone removal in this procedure consists of the following: •• 5 mm Spherical Bur •• Speed Control Guard

The surgical team will cover the NAVIO system touchscreen monitor with a sterile drape. This will allow the surgeon to manipulate the touchscreen with gloved, sterile, finger control to augment footpedal control of the software. The final draped monitor may look like Figure 5. Refer to the drape’s included instructions for use for how to properly apply to the monitor). Figure 5.

Patient Setup Avoid wrapping the ankle with bulky drapes / coverings. Using bulky material in this area may make it difficult to locate the Malleoli points during patient registration. Using a leg positioner (e.g., IMP’s De Mayo leg positioner), elevate the femur to approximately 45º and flex the knee to approximately 90º (Figure 6). If available, remove the pad on the operative leg side to allow the positioner to sit below hip level to provide natural kinematics during positioning and flexion.

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Figure 6.

1 System and Patient Setup Upon making the incision, carefully debride and inspect the joint. If any prominent spurs or osteophytes are present, especially in the area of the superior posterior femoral condyle, remove them with an osteotome or rongeur, as they could inhibit the leg motion. With medial compartment disease, osteophytes are typically found on the lateral aspect of the medial tibial eminence and anterior to the origin of the ACL.

Exposure •• Remove intracondylar osteophytes to avoid

impingement with the tibial spine or cruciate ligament, as well as peripheral osteophytes that interfere with the collateral ligaments and capsule. In order to reliably assess joint stability, it is crucial that all osteophytes are removed from the entire medial edge of both the femur and tibia.

•• Resect the deep menisco-tibial layer of the medial

capsule to provide access to any tibial osteophytes. Exposure can also be improved with excision of patellar osteophytes.

•• With the patient in the supine position, ensure the

knee is able to achieve 120 degrees of flexion. A larger incision may be necessary to create sufficient exposure.

•• Final debridement will be performed before

component implantation.

•• The NAVIO™ system technique is compatible with

the typical exposure recommendations for total knee arthroplasty.

•• For exposure recommendations specified by the

implant system manufacturer, please consult their instructions for use and product documentation.

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2 Bone Tracking Hardware Placing Tracking Hardware Rigid fixation of the femur and tibia tracking frames to the bone is critical for a successful NAVIO™assisted surgery. The NAVIO system utilizes a twopin bi-cortical fixation system. This fixation system is installed using bone screws, a tissue protector, and tracker clamps (2x) (Figure 7). Once fixed to the bone, the tracking frames (Figure 8) are oriented towards the optical tracking camera so the markers are in view. With the operative leg in 90 degrees of flexion, utilize the following procedure:

Tibia Tracker Array Placement •• Percutaneously place the first bone screw one

hand’s breadth (four fingers) inferior to the tibial tubercle on the medial side of the tibial crest (Figure 9.)

Figure 7.

•• Drill the bone screw into the tibia slowly,

perpendicular to the bony surface, taking care to engage the opposing cortex and stop.

•• Use the tissue protector to mark the position of the

second bone screw inferior to the initial placement. Engage the second screw with the bone through the tissue protector to ensure the pins are placed parallel to each other.

Femur Tracker Frame

•• Slide the bone clamp (with the clamp hardware

oriented towards the optical tracking camera) over the two bone screws until the bottom of the clamp is within 1 cm of the patient’s skin, taking care not to place the clamp touching the skin.

Tibia Tracker Frame

•• Clamp the tibia array into the bone clamp along

the length of the bar on the array. Place the smaller side of the arrays closest to the operative site (Figure 9). Orient the spheres towards the camera and slide the array away from the incision site.

Figure 8.

Femur Tracker Array Placement •• Percutaneously place the first bone screw one

hand’s breadth (five fingers) superior to the patella in the center of the femur (Figure 9).

•• Drill the bone screw into the femur slowly, taking

care to engage the opposing cortex and stop.

•• Utilize the tissue protector to mark the position of

the second bone screw. Engage the screw with the bone through the tissue protector to ensure the pins are placed parallel to each other. 12

Figure 9.

2 Bone Tracking Hardware •• Slide the tracker clamp (with the clamp opening

oriented towards the camera) over the two bone screws until the bottom of the clamp is within 1 cm of the patient’s skin, taking care not to place the clamp where it is touching the patient's skin.

•• Clamp the femur tracker frame into the bone clamp

along the length of the bar. Place the smaller side of the tracker frame closest to the operative site. Orient the spheres towards the camera and slide the array away from the incision site.

Confirm Array Visibility

Figure 10. Array Visibility in Deep Flexion

Prior to registering the leg with the NAVIO™ software, the user must confirm that the position of the optical tracking camera and tracker frames allow for full, uninterrupted visibility throughout the registration and cutting processes. Advance to the Camera Orientation Adjustment screen in the workflow and confirm visibility of the Femur (F) and Tibia (T) tracker frames in the following two positions: •• With the leg in deep flexion, ensure that the (F) is

visible in the camera’s field of view - oriented near the edge of the box (Figure 10).

•• With the leg in full extension, ensure that the (T) is

visible in the camera’s field of view (Figure 11). Both (F) and (T) icons should be located in the lowerthird of the Camera Orientation Adjustment screen, and in the farther third of the near-to-far range (Figure 11).

Figure 11. Array Visibility in Full Extension

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3 Surgical Preferences Workflow Preference The NAVIO™ Total Knee application allows the user to choose between a femur-first or a tibiafirst workflow. This Cutting Workflow preference provides flexibility and the option to either prepare the tibia first, prior to collecting soft tissue balancing information, or to collect the soft tissue balancing information before any bone cuts are performed. Once hardware connection, registration, and landmark point collection are complete, the femurfirst and tibia-first workflows can be broken down into the following stages, respectively: Femur First

Figure 12.

1. Ligament Stress Collection in extension and flexion (See Ligament Balancing - Section 5) 2. Femur Component Placement (See Implant Planning - Section 6) 3. Tibia Component Placement (See Implant Planning - Section 6) 4. Gap Balancing (See Soft Tissue Balancing- Section 7) 5. Femur and Tibia Bone Preparation (See Bone Cutting - Section 8) Tibia First 1. Tibia Component Placement (See Implant Planning - Section 6) 2. Tibia Bone Preparation (See Bone Cutting - Section 8) 3. Ligament Stress Collection in extension and flexion (See Ligament Balancing - Section 5) 4. Femur Component Placement (See Implant Planning Stage - Section 6) 5. Gap Balancing (See Soft Tissue Balancing- Section 7) 6. Femur Bone Preparation (See Bone Cutting - Section 8)

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Figure 13.

3 Surgical Preferences Rotational References The NAVIO™ Total Knee application allows the user to choose landmark collection preferences on the femur and the tibia in order to define rotational references, from which the implant component placement plan and ligament balancing information is calculated. For the femur, the following options are available to define the reference for computing the rotation of the component on the femur (Figure 14a): 1. Transepicondylar Axis 2. Femoral AP Axis 3. Posterior Condylar Axis

Figure 14a.

For the tibia bone, the following options are available to define the reference for computing the rotation of the component on the tibia (Figure 14b): 1. Tibia AP Axis 2. Mediolateral Axis 3. Transfer Femoral Mechanical Axis 4. Medial Third of the Tibia Tubercle

Based on the chosen preference for rotational reference, the collection stage is presented during registration of the patient anatomy. Further details on the above choices are highlighted in the Registration section, after femur and tibia landmark collections, respectively.

Figure 14b.

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3 Surgical Preferences Joint Line Selection Preference The joint line selection is an optional selection, which allows the user to choose a landmark point on the femur and/or tibia and offset a line perpendicular to the mechanical axis from that point to a chosen distance (Figure 15, 16). This reference line is then displayed during the implant planning stage, to guide the component placement.

Figure 15.

Figure 16.

Checkpoint Pins Checkpoint pins should be placed in both the femur and the tibia, in positions where they will not be removed during bone removal (Figure 17). These points are referenced using the point probe at set stages throughout the procedure to determine if either of the bone tracking frames have moved. Warning: Ensure that the checkpoint pins are placed away from the bone to be prepared, to avoid cutting through and dislocating the checkpoint pins.

Figure 17. 16

4 Registration CT-free Registration NAVIO’s™ CT-free registration process utilizes standard image-free principles in constructing a virtual representation of a patient’s anatomy and kinematics. The user may choose to move through the software’s workflow via the included NAVIO system footpedal or the touchscreen controls. Any collected point may be re-collected in sequence by moving backwards through the workflow stages.

Femur Neutral Position Place the leg in full extension, applying slight axial pressure to both compartments. Support the leg below the knee with one hand to avoid hyper-extension. This position will be utilized when calculating the patient’s preoperative varus / valgus deformity. Press and hold the right footpedal to collect the position (Figure 18). When the bar on the bottom reads as fully green (100%), release the footpedal to allow the software to automatically proceed to the next workflow step.

Figure 18.

Hip Center The Hip Center Calculation stage will follow the femoral tracker array through circular movements of the hip. These circular movements should be unrestricted and unhindered by holding/fixing equipment. Avoid pelvic movement, which can be a source of error. Prior to beginning collection, the femur should start in approximately 20º of hip flexion in order to provide enough room to rotate the hip in a wide circle. Slowly rotate the leg at the hip until all sectors of the graphic have changed to green (Figure 19).

Figure 19.

There should be no transmission of force from the femur onto the pelvis. Avoid a hip flexion angle greater than 45º.

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4 Registration Ankle Center Using the point probe, input the locations of the medial and lateral malleoli points by identifying the most prominent portion (Figure 20). Ensure that the point probe is visible throughout the point collection. If the probe is not visible, check that the tracking spheres on the point probe array are not overlapping (in front, or behind) the tracking spheres on the tibia tracker array.

Femoral Condyle

Figure 20.

There are four femoral landmark points to collect. These points are to be used as visual references during Implant Planning (Section 6). It is important to take care to understand where these points are taken on the patient’s bony anatomy so that they may be referenced properly during planning. Using the point probe, collect the following (Figures 21-24):

•• Knee Center

Mark the center of the knee, which will be referenced as part of the HKA (hip-knee-ankle) weight-bearing axis. This point collection, along with the hip center collection, defines the femur mechanical axis.

Figure 21.

•• Most Posterior Medial Point

Hyperflex the leg to access the most posterior points on the femoral condyle, marking the inflection point as the condyle curves posterior. This point is used in conjunction with the anterior notch point and the most posterior lateral point for initial sizing of the implant component.

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Figure 22.

4 Registration •• Most Posterior Lateral Point

This point is used in conjunction with the anterior notch point and the most posterior medial point for initial sizing of the implant component.

Figure 23.

•• Anterior Notch Point

This point is used as a reference during prosthesis planning to prevent notching of the implant component.

Figure 24.

•• Femoral Condyle Surface Mapping

The Femur Free Collection stage (Figure 25) offers a visualization of the femoral mechanical and rotational axis previously collected (blue lines) as well as the four discrete femur landmark points collected above (yellow dots). On top of this visualization, the user should digitize the femoral condyle by moving the point probe over the entire surface while holding down the footpedal. The user must input enough information into the system to appropriately localize the implant during planning. Hyperflex the leg to map the posterior portion. Manipulate the touchscreen to view the surfacemap input in 3D.

Figure 25.

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4 Registration Femoral Condyle Rotational References Based on surgeon preference, there are three options on which the femur rotational reference frame can be defined . These rotational references are used during Implant Planning (Section 6) for component placement onto the patient anatomy. It is important to understand how these collections are taken on the patient’s bony anatomy so that they may be referenced properly during planning. (Figures 26-29)

•• Transepicondylar Axis Collection

Figure 26.

If the epicondyles are selected as the preference for rotational reference collection, mark the medial and lateral epicondyles on the femur, which will be used to create the medial-lateral axis for the femur. The AP axis is then derived from the femur mechanical axis and the ML axis defined in this stage. •• Femoral AP Axis Collection

While the other collections listed are singular points referencing the tip of the point probe, this collection will reference the axis of the point probe. If Femoral AP Axis is selected for rotational reference collection, using the length of the pointer probe, collect the AP axis for the femur, normal to the transepicondylar axis. This collection, along with the femur mechanical axis will define the medial-lateral axis of the patient’s femur. Figure 27.

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