Anterior Cervical Cage System Surgical Technique - MT Ortho · Anterior Cervical Cage System Surgical Technique ... AFFINITY® ANTErIOr CErVICAl CAGE SYSTEM SurGICAl TECHNIquE

AFFINITY®

Anterior Cervical Cage System Surgical Techniqueas described by:

Thomas A. Zdeblick, M.D.University of Wisconsin Madison, Wisconsin

Table of Contents

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Implants & Instruments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Preoperative & Patient Positioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Incision & Exposure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Discectomy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Size Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Guide Sleeve Insertion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Endplate Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Cancellous Bone Harvest . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Bone Graft Packing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Cage Insertion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

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

SurGICAl TECHNIquE

AFFINITY® ANTErIOr CErVICAl CAGE SYSTEM

Introduction

Dear Colleagues,

In recent years, the use of interbody cages has grown in popularity as an alternative to conventional bone grafts . The design rationale for the AFFINITY® Anterior Cervical Cage System revolves around offering surgeons an attractive alternative to current methods of treating degenerative disc disease in the cervical spine . The AFFINITY® system uses a simple, easy-to-implant threaded cage, indicated for single-level ACDF’s . Its tapered design provides for optimal restoration of normal cervical lordosis . The wide range of sizes accommodates a large range of cervical anatomies .

The AFFINITY® cage is implanted via an open anterior approach . The versatile, straightforward design of the associated GENErAl INSTruMENTS allows for precise sizing of the disc space and end plate preparation . A series of sequential, color-coded instruments guide the surgeon through the procedure in a simple, intuitive manner . A trephine set included in the system allows for quick, minimally invasive access to the iliac crest for autologous cancellous bone harvest, which can be used to pack the cage prior to insertion .

The following monograph introduces the AFFINITY® Anterior Cervical Cage System along with the GENErAl INSTruMENTS designed specifically for its placement . My personal thoughts are included to reflect my clinical practice and operative techniques .

Sincerely,

Thomas A . Zdeblick, M .D .

university of Wisconsin

Madison, WI

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SurGICAl TECHNIquE


Implants & Instruments

IMPlANTS

instruments

Inserter

Impactor Sleeve

Trial

Guide Sleeve

ClOSED, CHAMFErED TIP• Guides insertion for

precise control • Helps prevent posterior

migration of packed autograft

lOrDODICAllY TAPErED, CYlINDrICAl DESIGN• Facilitates ease of insertion

• Provides stability • restores anatomical cervical lordosis

TITANIuM AllOY CONSTruCTION• Provides optimal fatigue strength

SElF-TAPPING THrEAD PATTErN• Facilitates optimal bone

purchase for stability and enhanced fixation

MulTIPlE THrOuGH-GrOWTH POrTS• Offers large capacity for packed autograft• Strategically aligned to interface endplates• Helps maximize porosity to enhance bony

through-growth and fusion

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SurGICAl TECHNIquE

reamer with T-Handle

reamer Guide Sleeve


Preoperative & Patient Positioning

Preoperatively, the surgeon must determine which intervertebral level to fuse . This may be done using a variety of diagnostic techniques, such as radiographs, MrI, discography, patient history, and physical examination .

The patient is placed in the supine position with the head in slight extension (FigUre 1) . The posterior cervical spine is supported to establish and maintain normal lordosis . The surgeon must then choose a right-sided or left-sided approach to the cervical vertebral column . After the approach is considered, the head may be rotated to allow for adequate exposure of the upper cervical spine .

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“Both shoulders are pulled down and secured with strips of adhesive tape.”

– T. Zdeblick, M.D.

“To identify the correct disc level, a needle is inserted into the intervertebral disc as a marker, and location is determined by means of a C-arm or a lateral radiograph.”


STEP 1

FigUre 1


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STEP 2

Incision & Exposure

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Typically, a transverse skin incision is made . An avascular dissection plane is developed between the trachea and esophagus, medially, and the carotid sheath, laterally . Hand-held retractors are utilized to provide initial exposure of the anterior vertebral column and the adjacent longus colli muscles (FigUre 2) .

After the anterior vertebral column has been exposed, the longus colli muscles are elevated and the medial/lateral self-retaining retractor blades are securely positioned beneath them (FigUre 3A) . The slotted blade may be used if an anterior osteophyte prevents proper positioning (FigUre 3b) .

FigUre 2

FigUre 3A

FigUre 3b


SurGICAl TECHNIquE

STEP 2

Incision & Exposure (Continued)

6

FigUre 5

FigUre 4

The longitudinal self-retaining retractor may be placed to provide optimal visualization (FigUre 4) .

A vertebral body distractor may also be used . The distraction pins are positioned midline in the vertebral bodies adjacent to the discectomy (FigUre 5) . The distractor is placed over the pins and the appropriate amount of distraction is applied .

“Place the distractor pins a sufficient distance away from the disc space to allow adequate room to perform the discectomy.”



SurGICAl TECHNIquE

STEP 3

Discectomy

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Discectomy is completed at the indicated level . Pituitaries, curettes and kerrisons may be used to remove the disc material and cartilage to expose the posterior longitudinal ligament (FigUres 6 AnD 7) .

FigUre 6

FigUre 7


SurGICAl TECHNIquE

STEP 3

Discectomy (Continued)

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FigUre 8

“I will typically use a burr to resect the overhanging lip of the superior endplate.”


FigUre 10

A high-speed drill with a burr (match tip/round) may be utilized for removal of the posterior disc and osteophyte(s) to achieve neural decompression (FigUres 8 AnD 9) . The posterior longitudinal ligament and osteophytes may be carefully removed . lightly burr the anterior surface of the vertebral bodies to remove any soft tissue and bony protrusions and create a flat surface, taking care to prevent excessive anterior bone removal (FigUre 10) .

FigUre 9


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STEP 4

FigUre 12

Size Selection

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FigUre 11

The AFFINITY® Anterior Cervical Cage is available in sizes ranging from 6 to 12mm diameters, in 12mm and 14mm lengths . The appropriate size is determined by selecting the Trial that provides the most satisfactory fit in the disc space (FigUre 11) . The Trials are color-coded to differentiate sizes and correlate to the color-coded label on the sterile package of the AFFINITY® Anterior Cervical Cage System . The corresponding instruments are also color-coded to simplify identification through the remainder of the procedure .

The Cage size can also be determined by using a caliper to measure the distracted disc height and the anterior/posterior vertebral body depth (FigUre 12) .

Correlating the measured distracted disc height to the AFFINITY® Cervical Cage can be accomplished in the following manner:

NOTE: Double (Bilateral) Instruments are not available in standard instrument set . Available only as a special request .

NOTE: Flanges on the Trial create a positive-stop at 12mm to prevent over insertion .

Measured Disc Height

superior Vertebral body

inferior Vertebral body

implant

DISC HEIGHT MEASurEMENT INSTruMENTATION AFFINITY CAGE

4mm 6mm (Gray) 6mm Double 5mm 7mm (Bronze) 7mm (Single or Double) 6mm 8mm (Violet) 8mm (Single or Double) 7mm 9mm (Green) 9mm 8mm 10mm (Blue) 10mm 9mm 11mm (Gold) 11mm 10mm 12mm (Gray) 12mm


SurGICAl TECHNIquE

STEP 5

Guide Sleeve Insertion

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Each color-coded Guide Sleeve has distraction prongs which are inserted into the intervertebral space to maintain distraction while the reaming is performed during Cage insertion . The Guide Sleeve is placed over the Trial of the corresponding color and inserted into the disc space, taking care to remain parallel to the endplates (FigUre 13A) . The Impactor Sleeve is then placed over the Trial and applied to the top surface of the Guide Sleeve and impacted to fully seat the Guide Sleeve into the disc space (FigUre 13b) . Once the Guide Sleeve is fully seated, the Trial and Impactor sleeved are removed (FigUre 13C) .

“Remove the anterior ridges to allow flush engagement of the sleeve distraction prongs.”


FigUre 13A FigUre 13b

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NOTE: The anatomic Guide Sleeve is designed to be used in a specific orientation . The Sleeve is marked INF for inferior and SuP for superior .

FigUre 13C


SurGICAl TECHNIquE

STEP 5

Guide Sleeve Insertion (Continued)

Once the Guide Sleeve has spikes on the end that engage the vertebral bodies to prevent additional distraction during the reaming operation . The Sleeve Cap is then impacted to fully engage the spikes into the vertebral bodies (FigUre 14A) .

It may be helpful to obtain a lateral radiograph at this time to ensure that the Guide Sleeve is fully seated on the vertebral bodies . Due to the angulation of the disc space, the Guide Sleeve may contact the inferior vertebral body and leave a slight gap between it and the superior vertebral body . This does not present a problem since the reaming Guide Sleeve has adjustable depths for reaming . Once the Sleeves are fully seated, the Sleeve Cap is removed (FigUre 14b) .

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NOTE: The Guide Sleeve spikes form a rectangular pattern . Place the enlongated dimension cephalad/Caudal to ensure the spikes span the disc space .

FigUre 14A FigUre 14b


SurGICAl TECHNIquE

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STEP 6

Endplate Preparation

The reaming Guide Sleeve has three adjustable settings for controlling reamer depth (FigUre 15) . The top surface of the Sleeve has hinged lids which can be flipped out of the way, or replaced to control the depth . With no lids removed, the reamer will extend into the disc space to a depth of 13mm . With one lid removed, the reamer will extend into the disc space to a depth of 15mm . removing the lids allows reaming to a depth of 17mm .

Once the proper depth is selected and the necessary sleeve setting obtained, the appropriately sized reamer can be inserted through the Sleeve (FigUre 16) . A detachable reamer T-Handle is connected to the reamer, and the reamer is inserted by hand and turned in a clockwise fashion to prepare the endplates . Each reamer has a stop and should be inserted until this stop firmly cotacts the Sleeve lid (FigUre 17) . remove the reaming Guide Sleeve once reaming is complete . An optional Sleeve remover is available to provide assistance if necessary (FigUre 18) .

“The cage should be slightly (1-2mm) recessed from the anterior surface for proper placement.”


“Save the reaming for later use as graft.”


FigUre 15 FigUre 16 FigUre 17 FigUre 18

13mm

15mm

17mm


SurGICAl TECHNIquE

STEP 7

Cancellous Bone Harvest

using the Trephine, cancellous bone can be harvested from the iliac crest to fill the AFFINITY® Cervical Cage . A small incision is made over the crest (approximately 1 .5cm), and blunt dissection is performed to expose the crest .

The Bone Trephine Sleeve is inserted and held firmly against the iliac crest (FigUre 19) . The Bone Trephine is inserted through the sleeve and turned in a clockwise direction to cut through the cortical and cancellous bone (FigUre 20) . The bone will be captured in the internal hole of the Bone Trephine . When fully inserted, the Trephine will extend approximately 25mm beyond the end of the sleeve .

Bone is extracted from the Trephine by inserting the Bone Trephine Punch into the handle of the Bone Trephine and pushing the bone out the toothed end of the instrument (FigUre 21) . The cortical shell can be removed and the cancellous bone prepared for compacting into the AFFINITY® Cervical Cage .

FigUre 19FigUre 20

FigUre 21

13 AFFINITY® ANTErIOr CErVICAl CAGE SYSTEM

SurGICAl TECHNIquE

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STEP 8

Bone Graft Packing

In order to pack the AFFINITY® Cervical Cage with bone graft, the holes in the Cage must be covered while the bone is inserted into the anterior opening . An Implant Holder is provided to cover the outer portion of the Cage, and features a series of holes for each Cage diameter . The AFFINITY® Cervical Cage is placed in the appropriate hole in the Holder with the open (anterior) end facing up . The collected autograft bone is then placed in the anterior hole of the Cage (FigUre 22A) and pressed into the Cage with the Bone Tamp . The table below specifies the thru-hole volume of each AFFINITY® Cervical Cage (FigUre 22b) .

FigUre 22A

CAViTy VolUMe CHArT

Size (mm) Thru-Hole Volume (cc)

6 x 12 0 .177 7 x 12 0 .210 8 x 12 0 .277 9 x 12 0 .314 10 x 12 0 .450 11 x 12 0 .499 12 x 12 0 .547 6 x 14 0 .199 7 x 14 0 .237 8 x 14 0 .309 9 x 14 0 .350 10 x 14 0 .507 11 x 14 0 .559 12 x 14 0 .606

FigUre 22b


SurGICAl TECHNIquE

STEP 9

Cage Insertion

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Once the Cage is sufficiently packed with bone, the Inserter is attached to the Cage . Three Inserters are designed for the seven Cage diameters . Shown below are the Inserter sizes and the Cages that each inserts .

The Inserter is applied to the Cage while it is still in the Implant Holder . The anterior face of the Cage has two driving slots, and the end of the Inserter has two tabs that fit in these slots . Once the Inserter is applied to the Cage, the Inserter shaft is screwed into the internal threaded hole . The AFFINITY® Cervical Cage can now be lifted from the Block (FigUre 23) .

The Inserter is turned in a clockwise fashion to screw the Cage into the prepared disc space . The Guide Sleeve distraction prongs maintain distraction while the Cage is inserted . The alignment of the Inserter handle must be medial/lateral to ensure proper orientation of the AFFiniTy® Cervical Cage opening to facilitate fusion (FigUre 24) . With the Inserter handle positioned medial/lateral, the elongated holes of the Cage will be aligned with the vertebral endplates . The Cage is flush with the vertebral bodies when the appropriate depth line on the Inserter shaft aligns with the top of the Guide Sleeve . To verify placement, slide the Guide Sleeve up the Inserter shaft . When proper depth and alignment are achieved, the Inserter shaft is unscrewed and the Inserter removed along with the Guide Sleeve .

Figure 23

“The alignment of the Inserter handle must be medial/lateral to ensure proper orientation of the Cage opening to facilitate fusion.”


inserTer AFFiniTy® CerViCAl CAge siZe (DiAMeTer)

Small 6mm, 7mm Medium 8mm, 9mm large 10mm, 11mm, 12mm

FigUre 24


SurGICAl TECHNIquE

STEP 9

Cage Insertion (Continued)

Following final Cage insertion, lateral and A/P radiographs may be taken to ensure proper placement . Figure 25 demonstrates both single and bilateral placement of the AFFINITY® Cervical Cage .

“When placing bilateral Cages, screw the first Cage into the prepared disc space halfway. Next, completely insert the second Cage to the proper depth and alignment. Then completely screw the first Cage to the proper depth and alignment.”


FigUre 25

NOTE: Implant Explantation The Cage may be removed by applying the appropriate Inserter from the General Instruments Set to the Cage (see Step 9) and screwing the Inserter shaft into the internal threaded hole . The Inserter is turned in a counterclockwise fashion to remove the implant .

16AFFINITY® ANTErIOr CErVICAl CAGE SYSTEM

SurGICAl TECHNIquE

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Product Ordering Information

general instruments

AFFiniTy® Anterior Cervical Cage

NOTE: Double (Bilateral) Instruments are not available in standard instrument set . Available only as a special request .

ITEM DESCrIPTION

6400856 6mm Double Trial

6400857 7mm Trial

6400858 8mm Trial

6400859 9mm Trial

6400860 10mm Trial

6400861 11mm Trial

6400862 12mm Trial



6400866 6mm Double Guide Sleeve

6400867 7mm Guide Sleeve








6400886 6mm Double Impactor Sleeve

6400887 7mm Impactor Sleeve








6400806 6mm Double reaming Guide Sleeve

6400807 7mm reaming Guide Sleeve






6400815 Sleeve Cap

6400816 Sleeve remover



6400826 6mm reamer

6400827 7mm reamer

6400828 8mm reamer

6400829 9mm reamer

6400830 10mm reamer

6400831 11mm reamer

6400832 12mm reamer

6400835 reamer T-Handle

6400840 Inserter, Small (6mm and 7mm)

6400841 Inserter, Medium (8mm and 9mm)

6400842 Inserter, large (10mm, 11mm, and 12mm)

6400845 Implant Holder

6400846 Bone Tamp

6400850 Bone Trephine Sleeve

6400852 Bone Trephine

6400854 Bone Trephine Punch

6390206 6mm x 12mm

6390207 7mm x 12mm

6390208 8mm x 12mm

6390209 9mm x 12mm

6390210 10mm x12mm

6390211 11mm x 12mm

6390212 12mm x 12mm

6390406 6mm x 14mm

6390407 7mm x 14mm

6390408 8mm x 14mm

6390409 9mm x 14mm

6390410 10mm x 14mm

6390411 11mm x 14mm

6390412 12mm x 14mm

ITEM DESCrIPTION

ITEM DESCrIPTION ITEM DESCrIPTION


SurGICAl TECHNIquE

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SElF-rETAINING rETrACTOrS AND BlADES

GrAFT HArVEST/PlACEMENT INSTruMENTS

Catalog # Description

875-050 l Hand-Held retractor, Straight, 18mm

875-051 l Small Hand-Held retractor, Straight, 18mm

875-052 l Hand-Held retractor, Back lip, 20mm

875-053 l Hand-Held retractor, Curved, 23mm

HAND-HElD rETrACTOrS


875-110 Transverse Self-retaining

retractor Frame

875-115 longitudinal Self-retaining

retractor Frame

875-148 retractor Blade Handle, Fixed

875-149 retractor Blade Handle,

rotating

Catalog# Description

875-150 23x30mmDiscectomyBlade





Catalog#Description

875-160 20x30mmLongitudinalBlade





Catalog#size

875-251 1mmKerrison

875-252 2mmKerrison

875-253 3mmKerrison

KErrISONS

Catalog#Description

875-300 Curettestraight6-0





875-307 Curettestraight2

Catalog#Description

875-310 CuretteAngled6-0






875-370 l Micro Curette Straight 6-0




MICrO CurETTES

CurETTES


875-380 l Micro Curette Angled 6-0





875-701 Graft Holder/Introducer

875-708 8mm Tapper

875-712 6x12mm Tapper

875-715 Mallet, 8”

Product Information

AnteriorCerviCALDisCeCtomy&fusioninstrumentsetTrIMlINE®


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AFFiniTy® AnTerior CerViCAl CAge sysTeM - important Medical informationCAUTION: Federal (USA) law restricts this device to sale by or on the order of a physician with appropriate training or experience.The following contains important medical information on the AFFINITY® Anterior Cervical Cage System.DESCRIPTION:The AFFINITY® Anterior Cervical Cage System consists of a hollow, threaded, tapered metal device which inserts into the intervertebral disc space. The AFFINITY® implants are available in diameters ranging from 6mm to 12mm and in lengths ranging from 12mm to 14mm.The AFFINITY® implants are made from implant grade titanium alloy (Ti-6Al-4V) described by ASTM F136 or its ISO equivalent. No warranties, express or implied, are made. Implied warranties of merchantability and fitness for a particular use are specifically excluded. INDICATIONS:The AFFINITY® Anterior Cervical Cage System is indicated for anterior cervical interbody fusion procedures in skeletally mature patients with cervical disc disease at one level from the C2-C3 disc to the C7-T1 disc. Cervical disc disease is defined as intractable radiculopathy and/or myelopathy with herniated disc and/or osteophyte formation on posterior vertebral endplates producing symptomatic nerve root and/or spinal cord compression confirmed by radiographic studies. AFFINITY® implants are to be used with autogenous bone graft and implanted via an open, anterior approach. CONTRAINDICATIONS:The AFFINITY® Anterior Cervical Cage System should not be implanted in patients with an active infection or with an allergy to titanium or titanium alloy.PRECAUTIONS:CAUTION:The AFFINITY® Anterior Cervical Cage System should only be used by surgeons who are experienced in cervical interbody fusion procedures and have undergone adequate training with this device. A lack of adequate experience and/or training may lead to a higher incidence of adverse events, such as neurological complications.ADVERSE EVENTS:The adverse events, as shown in Table 1, were reported from the 202 AFFINITY® device patients and 62 control patients enrolled in multi-center clinical studies. The control treatment was a single level anterior interbody fusion procedure with iliac crest-derived autogenous bone. The following table lists the adverse events in alphabetical order. Note: Some patients experienced more than one adverse event.

The most noteworthy adverse events in the AFFINITY® device group were neurological complications and spinal events. A total of 15 upper and lower body neurological events occurred in 15 patients in the AFFINITY® device group. These events included: 9 events of tingling and/or numbness in arms or hands either with or without associated pain; 2 cases of new myelopathy; 1 event producing leg numbness symptoms; 1 case of hand cramping; 1 Morton’s neuroma of the foot; and 1 median nerve entrapment which was not carpal tunnel.A total of 29 spinal events occurred in 27 patients in the AFFINITY® device group. These events included the following: 6 cervical spondyloses, 4 cases of herniated nucleus pulposus in the cervical spine; 3 cervical degenerative disc disease; 1 cervical arthritis; 1 bone spur; 1 thoracic herniated nucleus pulposus and 13 lumbar associated events, such as degenerative disc disease.In addition, there were 29 patients in the AFFINITY® device group who had 35 reports of neck and/or arm pain. Of the 14 events reported between surgery discharge and 6 months postoperatively, 7 involved neck pain including muscle cramps or strains, 6 involved shoulder or arm pain including rotator cuff injuries, and 1 involved hand pain. Of the 10 events occurring between 6 and 12 months postoperatively, 5 involved neck and arm pain, 4 involved shoulder pain including 1 rotator cuff tendonitis, and 1 involved cervical muscle pain and headache. Eleven events occurred at least 12 months after the initial surgery. Of these, 3 involved shoulder pain, 4 involved neck and/or arm pain, 1 involved arm pain associated with fatigue, 1 involved joint pain in neck, shoulders, back, and hands, 1 involved elbow pain, and 1 involved thoracic pain.

In addition to the 35 reports of neck/arm pain, Table 1 includes 15 patients who reported hand pain. Of the 50 patients reporting neck/arm/hand pain symptoms, 35 of the complaints could be attributed to the operative or adjacent levels. Of the 50 patients complaining of postoperative neck, arm and hand symptoms, 10 were considered neck pain failures and 7 were considered arm pain failures according to the success/failure criteria.

TABLE I - ADVERSE EVENTS

Surgery Postoperative (1 day to 1 Month)

6 Weeks (1 Month to 2 Months)

3 Months (2 Months to 5 Months)



24 Months (or greater)

(19 Months to 48 Months)

Total Adverse Events

Adverse Event AFFINITY N=202

Control1

N=62AFFINITYN=202

ControlN=62

AFFINITYN=200

ControlN=58

AFFINITYN=191

ControlN=58

AFFINITYN= 186

ControlN= 57

AFFINITYN= 178

ControlN= 50

AFFINITY N=174

ControlN= 47

AFFINITY Control

Anatomical/Technical Difficulty 1 3 0 0 0 0 0 0 0 0 0 0 0 0 1 3

Cancer 0 0 0 0 0 0 0 0 1 0 1 0 0 0 2 0

Cardio/Vascular 0 0 3 2 0 0 0 0 0 0 1 3 1 1 5 6

Carpal Tunnel Syndrome 0 0 0 0 0 0 1 0 1 0 5 0 0 0 7 0

Dural Tear 1 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0

Dysphonia/Dysphagia 0 0 5 4 3 0 0 2 0 0 0 0 0 0 8 6

Gastrointestinal 0 0 7 0 1 1 0 0 0 0 5 1 3 0 16 2

Graft Site Related 0 0 5 2 0 1 0 0 0 0 0 0 0 0 5 3

Implant Displacement/ Loosening/Collapse

0 0 0 1 0 2 0 3 0 2 0 1 0 0 0 9

Infection 0 0 5 0 1 0 0 0 0 1 1 2 0 2 7 5

Malpositioned Implant 0 0 1 0 0 0 0 0 0 0 0 0 0 0 1 0

Neck and/or Arm Pain 0 0 2 0 7 0 5 2 5 1 10 2 6 1 35 6

Neurological Upper Body2

Lower Body3 0 0

0 0

1 0

4 1

3 1

1 0

1 0

3 1

0 0

3 1

5 0

2 2

3 1

4 0

13 2

17 5

Non-Union4

Non-Union Pending5 0 0

0 0

0 0

0 0

0 0

0 0

0 1

0 3

3 1

2 0

2 1

1 2

3 1

2 0

8 4

5 5

Other Pain6 0 0 1 0 1 0 1 1 2 0 5 1 3 2 13 4

Respiratory 0 1 0 1 0 0 0 0 0 0 0 0 0 0 0 2

Spinal Event:Cervical SpineThoracic SpineLumbar Spine

0 0 0

0 0 0

0 0 0

0 0 0

2 0 0

0 0 0

3 1 5

3 0 0

2 0 5

0 0 1

5 0 2

3 0 0

3 0 1

2 0 0

15 1 13

8 0 1

Subsidence 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0

Trauma 0 0 3 0 1 0 10 1 6 1 5 0 5 4 30 6

Urogenital 0 0 2 4 0 0 0 0 2 0 0 1 1 0 5 5

Vascular Intra-op 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 1

Other7 0 0 3 2 1 0 0 1 0 1 6 1 6 4 16 9

1 Control = Patients receiving the autograft treatment.2 Neurological adverse events that affected the upper body, i.e., arms, neck, etc.3 Neurological adverse events that affected the lower body, i.e, legs, feet, etc.4 Non-union adverse events that have resulted in a second surgery. 5 Non-union adverse events that have not resulted in a second surgery.

6 “Other pain” consists of pain that is not related to the surgery or the treatment area. Examples are bursitis, knee pain, back pain, migraine headaches.

7 The “Other” adverse event category consists of the following adverse events reported in the clinical trial: allergy/rash, allergic reaction to chemotherapy, chemotherapy side effects, cholecystectomy, diabetes, elevated temperature,

fibromyalgia, hardware removal, hearing loss and cataracts, hepatomegaly, Horner’s Syndrome, joint crepitus, low B12 and folate, malpositioned cervical plate, narcotic addiction, psychological disorder, and toothache.

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Table II presents the Bayesian statistical comparison of adverse events between the AFFINITY® device group and the control treatment group.

Some of the adverse events led to surgical interventions subsequent to the clinical trial surgery. These surgical interventions can be classified as revisions, removals, supplemental fixations, reoperations, and other (see footnotes below Table III for an explanation of these terms). Table III summarizes the secondary surgical interventions in the AFFINITY™ device and control treatment groups in the 12-Month and 24-Month post-operative intervals. Table III also presents the Bayesian statistical comparison of secondary surgeries between the AFFINITY™ device group and the control treatment group.

Of the 47 patients in the AFFINITY® device group who required a second surgery, 8 had surgery for non-union, 7 had surgery for neck and/or arm pain, 5 had surgery to treat a lumbar condition, 5 required surgery due to trauma, and 3 had surgery to treat carpal tunnel syndrome. Most of the second surgeries occurred up to and including the 12-Month post-operative interval.Potential Adverse Events:The following is a list of potential adverse events which may occur with cervical interbody fusion surgery with the AFFINITY® Anterior Cervical Cage System. Some of these adverse events may have been previously reported in the adverse events table.• Bending, breakage, loosening, and/or migration of components • Non-union (or pseudarthrosis), delayed union, mal-union• Foreign body (allergic) reaction • Cessation of any potential growth of the operated portion of the spine. Loss of spinal mobility or function• Tissue or nerve damage • Graft donor site complications• Post-operative change in spinal curvature, loss of correction, height, and/or reduction • Damage to blood vessels and cardiovascular system compromise• Infection • Gastrointestinal complications• Dural tears • Damage to internal organs and connective tissue• Neurological system compromise • Development of respiratory problems• Dysphagia/dysphonia • Incisional complications• Scar formation • Change in mental status• Bone fracture • DeathNote: Additional surgery may be necessary to correct some of these potential adverse events.

TABLE II - BAYESIAN COMPARISON OF ADVERSE EVENTS

Adverse Event

There is a 95% Probability that adverse event rates will fall between the following ranges

AFFINITY® Device Control

Anatomical/Technical Difficulty 0% to 3% 2% to 13%

Cancer 0% to 4% 0% to 6%

Cardio/Vascular 2% to 32% 6% to 52%

Carpal Tunnel Syndrome 2% to 7% 0% to 6%

Dural Tear 0% to 3% 0% to 6%

Dysphonia/Dysphagia 3% to 11% 2% to 15%

Gastrointestinal 6% to 15% 1% to 9%

Graft Site Related 2% to 47% 3% to 54%

Implant Displacement / Loosening / Collapse 0% to 2% 8% to 25%

Infection 2% to 10% 0% to 12%

Malpositioned Implant 0% to 3% 0% to 6%

Neck and/or Arm Pain 12% to 23% 3% to 16%

Neurological 4% to 12% 26% to 53%

Non-Union (Outcome Pending) 1% to 7% 2% to 21%

Other Pain 3% to 11% 2% to 19%

Respiratory 0% to 2% 1% to 11%

Spinal Event 10% to 23% 7% to 27%

Subsidence 0% to 3% 0% to 6%

Trauma 5% to 47% 6% to 35%

Urogenital 1% to 7% 3% to 23%

Vascular Intraop 0% to 2% 0% to 9%

Other Adverse Event 5% to 13% 5% to 24%

Any Adverse Event 46% to 60% 55% to 81%

TABLE III - SECONDARY SURGICAL PROCEDURES

Clinical Comparison of Secondary SurgeriesBayesian Statistical

Comparison of Second Surgeries

Type of SecondarySurgical Procedure

Up to 12 Months(1 day to 19 Months)

24 Months or Later(19 Months to 48 Months) Total Events4

There is a 95% Probability thatSecond Surgery rates will fallbetween the following ranges

Type of SecondarySurgical Procedure3

AFFINITY®

N=178Control1

N=50AFFINITY®

N=174ControlN=47 AFFINITY® Control AAFFINITY®

Cage System Control

Revision 3 5 0 2 3 7 1% to 31% 6% to 58%

Removal 2 0 3 0 5 0 1% to 6% 0% to 6%

Supplemental Fixation 5 0 1 0 6 0 1% to 6% 0% to 6%

Reoperation 1 2 1 0 2 2 0% to 4% 1% to 11%

Other2 27 5 4 3 31 8 9% to 19% 8% to 30%

1 Control, i.e., patients receiving the autograft treatment2 Other Second Surgery is any surgical procedure not classified as a revision, removal, supplemental fixation, or a reoperation such as surgeries for hernias, rotator cuff tears, lumbar adverse events, carpal tunnel syndrome, cervical

adverse events that occurred at a different level, etc.3 Revision: A procedure that adjusts or in any way modifies the original implant configuration. Removal: A procedure at the involved level that removes one or more components of the original implant

configuration without replacement with the same type of trial device. Supplemental Fixation: A procedure at the involved level in which additional cervical fixation devices that are not

approved as part of the protocol are placed.

Reoperation: Any surgical procedure at the involved level that is not classified as a Removal, Revision, or Supplemental Fixation, such as a procedure for wound drainage of the graft site.

Other: Any surgical procedure not classified as a revision, removal, supplemental fixation, or a reoperation, such as surgeries for hernias, rotator cuff tears, lumbar adverse events, carpal tunnel syndrome, cervical adverse events that occurred at a different level, etc.

4 Some patients experienced more than one second surgery.

21

CLINICAL RESULTS:STUDY DESIGN AND PURPOSEA prospective, multi-center, controlled clinical trial of the AFFINITY® Anterior Cervical Cage System was conducted in the United States to determine the safety and effectiveness of the anterior cervical use of the AFFINITY® device in the treatment of patients with symptomatic cervical disc disease. Investigational patients were treated with the AFFINITY® device filled with autogenous bone derived from the iliac crest. Control patients were treated with iliac crest-derived autogenous bone.The effectiveness measures selected for this investigation included whether the treated disc level fused, whether there was relief from neck pain and disability, and whether the neurologic status was maintained or improved. Safety was evaluated with an analysis of reported adverse events and second surgeries.METHODSInclusion criteria for the clinical trial included symptomatic cervical disc disease as noted by intractable radiculopathy and/or myelopathy with herniated disc and/or osteophyte formation on posterior vertebral endplates producing symptomatic nerve root and/or spinal cord compression documented by diagnostic imaging finding(s); single level involvement from C2-C3 disc to C7-T1 disc; unresponsive to 6 weeks conservative treatment or the presence of progressive symptoms or signs of nerve root or spinal cord compression in the face of continued non-operative management. Specifically excluded from the clinical trial were patients who had: a previous surgical intervention at the involved spinal level; osteopenia, osteoporosis, or osteomalacia or metabolic bone disease; instability greater than 3.5 mm translation or 11° of angular motion; overt or active spinal and/or systemic infection; pregnancy; or a condition which required postoperative medications that interfere with fusion such as steroids.Patients were evaluated preoperatively, perioperatively, and postoperatively at 6 weeks, 3, 6, 12, and 24 months. For this clinical trial, overall success was the primary endpoint. Overall success was based on a patient demonstrating fusion, pain and disability success, neurological success, and no secondary surgical procedure classified as a revision, removal or supplemental fixation. Fusion was based on angular motion and lucent line criteria and was assessed from static and dynamic radiographs. Pain and disability were measured using the Neck Disability Index. Success was based on the postoperative score being better than the preoperative score by at least 15 points if the preoperative score was at least 30 points or by at least 50% if the preoperative score was less than 30 points. If the preoperative NDI score was zero, the postoperative score also had to be zero for success. Neurological status was evaluated based on sensory, motor, reflex, and foraminal compression test assessments and success was based on a postoperative maintenance or improvement in condition as compared to the preoperative status.STATISTICAL ANALYSESThe results of the clinical study were evaluated using Bayesian statistical methods. All patients involved in the clinical trial of the AFFINITY® Anterior Cervical Cage System and the control group studies were enrolled under the same inclusion/exclusion criteria. To substantiate the comparability of the two groups, a logistic regression analysis was performed which examined the relationship of all demographic, preoperative medical conditions and preoperative measurements of effectiveness variables on the overall success results. All preoperative variables were considered as covariate candidates and the five most influential ones (gender, preoperative work status, tobacco use, neurological compression test (F.C.T.) reaction, and whether a patient had preoperative radicular symptoms) were incorporated into covariate analyses of the outcome parameters, thereby adjusting the posterior probabilities in accordance with their influence. Consequently, based on this statistical methodology, the most influential prognostic differences between the two treatment groups for demographic and preoperative information were taken into account in assessing the outcome parameters.A small fraction of the patients did not have their 24-month postoperative evaluations when the results were analyzed. Their 24-month results were predicted from their 12-month outcomes and the relationship established from patients that had both 12 and 24-month evaluations.PATIENT POPULATIONA total of 202 patients were enrolled in the investigational AFFINITY® device treatment group and a total of 62 control patients were entered into clinical studies in both the U.S. and U.K. The mean ages for patients in the AFFINITY® device and control treatment groups were 44.5 and 50.1 years, respectively. Approximately 52% of the AFFINITY® device patients were males as compared to 57% for the control group. Tobacco use in the control group occurred in approximately 48% of the patients and in 36% of the AFFINITY® device patients. Over 64% of the AFFINITY® device patients were working prior to surgery as compared to a 31% rate for the control patients.RESULTSThe adjusted posterior means of success probabilities for the primary effectiveness parameters, including overall success, at 24 months postoperative can be found in Table IV.

* There is a 95% probability that success rates will fall between the ranges listed.In Table IV, neurological success is defined as success in 3 of the 4 subsections (sensory, motor, reflex, and foraminal compression test) as per the protocol. If neurological success required successes in 4 of 4 subsections, 13 of 171 AFFINITY® device patients and 16 of 45 control patients would not be a neurological success. Of the 13 AFFINITY® patients, there were ten patients with reflex deficits and three with sensory deficits. Eight of these deficits are associated with the operative or adjacent levels.PACKAGING:Packages for each of the components should be intact upon receipt. If a loaner or consignment system is used, all sets should be carefully checked for completeness and all components including instruments should be carefully checked to ensure that there is no damage prior to use. Damaged packages or products should not be used, and should be returned to Medtronic Sofamor Danek.CLEANING AND DECONTAMINATION:

If not supplied sterile, all implants and instruments must first be cleaned using established hospital methods before sterilization and introduction into a sterile surgical field. Used instruments must be decontaminated, cleaned, and sterilized before reuse. Also, some instruments, such as the reamer/T-handle, require dismantling before cleaning.

Cleaning and disinfecting of instruments can be performed with alkali aldehyde-free solvents at higher temperatures. Cleaning and decontamination can include the use of neutral cleaners followed by a deionized water rinse.

Note: certain cleaning solutions such as those containing formalin, glutaraldehyde, bleach and/or other alkaline cleaners may damage some devices, particularly instruments; these solutions should not be used.

All products should be treated with care. Improper use or handling may lead to damage and possible improper functioning of the device.STERILIZATION:If not supplied sterile, the implants and instruments must be sterilized prior to use. Non-sterile implants and instruments are recommended to be steam sterilized by the hospital using one of the following process parameters:

* NOTE: For use of this product and instruments outside the United States, some non-U.S. Health Care Authorities recommend sterilization according to these parameters so as to minimize the potential risk of transmission of Creutzfeldt-Jakob disease, especially of surgical instruments that could come into contact with the central nervous system.Remove all packaging material prior to sterilization. Only sterile implants and instruments should be used in surgery. No implant should be re-used once it comes into contact with human tissue or body fluid. Always immediately clean and re-sterilize instruments that have been used in surgery. This process must be performed before handling or (if applicable) returning to Medtronic Sofamor Danek.PRODUCT COMPLAINTS:Any health care professional (e.g., customer or user of this system of products), who has any complaints or who has experienced any dissatisfaction in the quality, identification, durability, reliability, safety, effectiveness and/or performance of this product, should notify the distributor, Medtronic Sofamor Danek. Further, if any of the implanted AFFINITY® Anterior Cervical Cage System components ever “malfunction,” (i.e., do not meet any of their per-formance specifications or otherwise do not perform as intended), or are suspected of doing so, the distributor should be notified immediately. If any Medtronic Sofamor Danek product ever “malfunctions” and may have caused or contributed to the death or serious injury of a patient, the distributor should be notified immediately by telephone, fax or written correspondence. When filing a complaint, please provide the component name and number, lot number, your name and address, the nature of the complaint and notification of whether a written report from the distributor is requested.DEVICE RETRIEVAL EFFORTS:Should it be necessary to remove an AFFINITY® Anterior Cervical Cage System, please call Medtronic Sofamor Danek.

TABLE IV – POSTERIOR MEANS (95% HPD CREDIBLE INTERVALS) OF SUCCESS PROBABILITIESFOR PRIMARY EFFECTIVENESS VARIABLES

24 Months

AFFINITY® DeviceSuccess Rate (Range*)

ControlSuccess Rate (Range*)

Overall Success 68% (60% to 74%) 61% (48% to 75%)

Fusion 94% (63% to 97%) 86% (68% to 99%)

NDI Pain/Disability Improvement 75% (68% to 81%) 75% (62% to 87%)

Neurological Status Maintenance or Improvement 96% (87% to 100%) 78% (45% to 92%)

STERILIZATION METHODS

Method Cycle Temperature Exposure Time

Steam Gravity 250°F (121°C) 30 Min.

*Steam Gravity 273°F (134°C) 20 Min.

Steam Pre-Vacuum 270°F (132°C) 5 Min.

IN USA ManagerCustomer Service DivisionMedtronic Sofamor Danek USA, Inc.1800 Pyramid PlaceMemphis, Tennessee 38132

Telephone: 800-876-3133 800-933-2635 or 901-396-3133

IN EUROPE Sofamor SNC**13, rue de la perdrix93290 TREMBLAYFRANCETelephone: (33) 1.49.38.80.00**authorized representative

Supplied by Medtronic Sofamor Danek©2002 Medtronic Sofamor Danek USA, Inc. All rights reserved

MlITAFFST5A5IrN1231/115©2005 Medtronic Sofamor Danek uSA, Inc . All rights reserved .

MEDTrONIC SOFAMOr DANEK uSA, INC .Spinal Division Worldwide Headquarters1800 Pyramid PlaceMemphis, TN 38132(901) 396-3133(800) 876-3133Customer Service: (800) 933-2635

www .sofamordanek .comFor more information go to www .myspinetools .com

The surgical technique shown is for illustrative purposes only . The technique(s) actually employed in each case will always depend upon the medical judgement of the surgeon exercised before and during surgery as to the best mode of treatment for each patient .

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Anterior Cervical Cage System Surgical Technique - MT Ortho · Anterior Cervical Cage System Surgical Technique ... AFFINITY® ANTErIOr CErVICAl CAGE SYSTEM SurGICAl TECHNIquE