AFFINITY. Anterior Cervical Cage System Surgical Technique. as described by: Thomas A. Zdeblick, M.D. University of Wisconsin Madison, Wisconsin

Transcription

1 AFFINITY Anterior Cervical Cage System Surgical Technique as described by: Thomas A. Zdeblick, M.D. University of Wisconsin Madison, Wisconsin

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3 Table of Contents surgical technique Introduction Implants & Instruments Preoperative & Patient Positioning Incision & Exposure Discectomy Size Selection Guide Sleeve Insertion Endplate Preparation Cancellous Bone Harvest Bone Graft Packing Cage Insertion Product Ordering Information

4 surgical technique 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 2

5 Implants & Instruments surgical technique Implants LORDODICALLY Tapered, Cylindrical Design Facilitates ease of insertion Provides stability Restores anatomical cervical lordosis 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 Titanium Alloy Construction Provides optimal fatigue strength instruments Self-tapping Thread Pattern Facilitates optimal bone purchase for stability and enhanced fixation Closed, Chamfered Tip Guides insertion for precise control Helps prevent posterior migration of packed autograft Trial Guide Sleeve Impactor Sleeve Reamer Guide Sleeve Reamer with T-Handle Inserter 3

6 surgical technique step 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 ). 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. 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. Figure T. Zdeblick, M.D. 4

7 Incision & Exposure 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). surgical technique step 2 Figure 3A Figure 3B Figure 2 5

8 surgical technique step 2 Incision & Exposure (Continued) 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. T. Zdeblick, M.D. Figure 4 Figure 5 6

9 Discectomy 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). surgical technique step 3 Figure 6 Figure 7 7

10 Discectomy (Continued) surgical technique step 3 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 ). Figure 9 Figure 8 I will typically use a burr to resect the overhanging lip of the superior endplate. T. Zdeblick, M.D. Figure 8

11 Size Selection The AFFINITY Anterior Cervical Cage is available in sizes ranging from 6 to 2mm diameters, in 2mm and 4mm lengths. The appropriate size is determined by selecting the Trial that provides the most satisfactory fit in the disc space (Figure ). The Trials are color-coded to differentiate sizes and correlate to the colorcoded 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 2). Correlating the measured distracted disc height to the AFFINITY Cervical Cage can be accomplished in the following manner: surgical technique step 4 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 mm (Blue) mm 9mm mm (Gold) mm mm 2mm (Gray) 2mm NOTE: Double (Bilateral) Instruments are not available in standard instrument set. Available only as a special request. NOTE: Flanges on the Trial create a positivestop at 2mm to prevent over insertion. Superior Vertebral Body Implant Measured Disc Height Inferior Vertebral Body Figure Figure 2 9

12 surgical technique step 5 Guide Sleeve Insertion 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 3A). 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 3B). Once the Guide Sleeve is fully seated, the Trial and Impactor sleeved are removed (Figure 3C). 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. Remove the anterior ridges to allow flush engagement of the sleeve distraction prongs. T. Zdeblick, M.D. Figure 3A Figure 3B Figure 3c 8

13 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 4A). 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 4B). surgical technique step 5 NOTE: The Guide Sleeve spikes form a rectangular pattern. Place the enlongated dimension cephalad/ Caudal to ensure the spikes span the disc space. Figure 4A Figure 4B

14 surgical technique step 6 The cage should be slightly (-2mm) recessed from the anterior surface for proper placement. T. Zdeblick, M.D. Endplate Preparation The Reaming Guide Sleeve has three adjustable settings for controlling Reamer depth (FIGURE 5). 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 3mm. With one lid removed, the Reamer will extend into the disc space to a depth of 5mm. Removing the lids allows reaming to a depth of 7mm. Once the proper depth is selected and the necessary sleeve setting obtained, the appropriately sized Reamer can be inserted through the Sleeve (FIGURE 6). 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 7). Remove the Reaming Guide Sleeve once reaming is complete. An optional Sleeve Remover is available to provide assistance if necessary (FIGURE 8). Save the reaming for later use as graft. T. Zdeblick, M.D. 3mm 5mm 7mm Figure 5 Figure 6 Figure 7 Figure 8 2

15 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.5cm), and blunt dissection is performed to expose the crest. The Bone Trephine Sleeve is inserted and held firmly against the iliac crest (Figure 9). The Bone Trephine is inserted through the sleeve and turned in a clockwise direction to cut through the cortical and cancellous bone (Figure 2). 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 2). The cortical shell can be removed and the cancellous bone prepared for compacting into the AFFINITY Cervical Cage. surgical technique step 7 Figure 2 Figure 9 Figure 2 3

16 surgical technique 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). Cavity Volume Chart Size (mm) Thru-Hole Volume (cc) 6 x x x x 2.34 x 2.45 x x x x x x 4.35 x 4.57 x x 4.66 Figure 22B Figure 22A 4

17 Cage Insertion 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. surgical technique step 9 inserter Small Medium Large AFFINITY cervical cage Size (diameter) 6mm, 7mm 8mm, 9mm mm, mm, 2mm 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. Figure 24 T. Zdeblick, M.D. 5

18 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. Figure 25 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. T. Zdeblick, M.D. 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. 6

19 Product Ordering Information surgical technique AFFINITY Anterior Cervical Cage ITEM DESCRIPTION ITEM DESCRIPTION mm x 2mm mm x 2mm mm x 2mm mm x 2mm 6392 mm x2mm 6392 mm x 2mm mm x 2mm mm x 4mm mm x 4mm mm x 4mm mm x 4mm 6394 mm x 4mm 6394 mm x 4mm mm x 4mm General Instruments ITEM DESCRIPTION ITEM DESCRIPTION mm Double Reaming Guide Sleeve mm Reaming Guide Sleeve mm Reaming Guide Sleeve mm Reaming Guide Sleeve 648 mm Reaming Guide Sleeve 648 mm Reaming Guide Sleeve mm Reaming Guide Sleeve 6485 Sleeve Cap 6486 Sleeve Remover mm Double Reaming Guide Sleeve mm Double Reaming Guide Sleeve mm Reamer mm Reamer mm Reamer mm Reamer 6483 mm Reamer 6483 mm Reamer mm Reamer Reamer T-Handle 6484 Inserter, Small (6mm and 7mm) 6484 Inserter, Medium (8mm and 9mm) Inserter, Large (mm, mm, and 2mm) Implant Holder Bone Tamp 6485 Bone Trephine Sleeve Bone Trephine Bone Trephine Punch mm Double Trial mm Trial mm Trial mm Trial 6486 mm Trial 6486 mm Trial mm Trial mm Double Trial mm Double Trial mm Double Guide Sleeve mm Guide Sleeve mm Guide Sleeve mm Guide Sleeve 6487 mm Guide Sleeve 6487 mm Guide Sleeve mm Guide Sleeve mm Double Guide Sleeve mm Double Guide Sleeve mm Double Impactor Sleeve mm Impactor Sleeve mm Impactor Sleeve mm Impactor Sleeve 6489 mm Impactor Sleeve 6489 mm Impactor Sleeve mm Impactor Sleeve mm Double Impactor Sleeve mm Double Impactor Sleeve NOTE: Double (Bilateral) Instruments are not available in standard instrument set. Available only as a special request. 7

20 Product Information TRIMLINE anterior Cervical Discectomy & fusion instrument set HAND-HELD RETRACTORS Catalog # Description Hand-Held Retractor, Straight, 8mm Small Hand-Held Retractor, Straight, 8mm Hand-Held Retractor, Back Lip, 2mm Hand-Held Retractor, Curved, 23mm SELF-RETAINING RETRACTORS AND BLADES Catalog # Description Catalog # Description Catalog # Description 875- Transverse Self-Retaining Retractor Frame Longitudinal Self-Retaining Retractor Frame Retractor Blade Handle, Fixed Retractor Blade Handle, Rotating CURETTES Catalog # Description Curette Straight Curette Straight Curette Straight Curette Straight Curette Straight Curette Straight 2 MICRO CURETTES Catalog # Description Micro Curette Straight Micro Curette Straight Micro Curette Straight Micro Curette Straight x3mm Discectomy Blade x4mm Discectomy Blade x5mm Discectomy Blade x6mm Discectomy Blade x7mm Discectomy Blade Catalog # Description Curette Angled Curette Angled Curette Angled Curette Angled Curette Angled - Catalog # Description Micro Curette Angled Micro Curette Angled Micro Curette Angled Micro Curette Angled x3mm Longitudinal Blade x4mm Longitudinal Blade x5mm Longitudinal Blade x6mm Longitudinal Blade x7mm Longitudinal Blade KERRISONS Catalog # Size mm Kerrison mm Kerrison mm Kerrison GRAFT HARVEST/PLACEMENT INSTRUMENTS Catalog # Description Graft Holder/Introducer mm Tapper x2mm Tapper Mallet, 8 8

21 - Important Medical Information CAUTION: 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 2mm and in lengths ranging from 2mm to 4mm. The AFFINITY implants are made from implant grade titanium alloy (Ti-6Al-4V) described by ASTM F36 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-T 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, were reported from the 22 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. TABLE I - ADVERSE EVENTS Surgery Postoperative ( day to Month) 6 Weeks ( Month to 2 Months) 3 Months (2 Months to 5 Months) 6 Months (5 Months to 9 Months) 2 Months (9 Months to 9 Months) 24 Months (or greater) (9 Months to 48 Months) Total Adverse Events Adverse Event AFFINITY N=22 Control N=62 AFFINITY N=22 Control N=62 AFFINITY N=2 Control N=58 AFFINITY N=9 Anatomical/Technical Difficulty 3 3 Cancer 2 Cardio/Vascular Carpal Tunnel Syndrome 5 7 Dural Tear Dysphonia/Dysphagia Gastrointestinal Graft Site Related Control N=58 AFFINITY N= 86 Control N= 57 AFFINITY N= 78 Control N= 5 AFFINITY N=74 Control N= 47 AFFINITY Control Implant Displacement/ Loosening/ Collapse Infection Malpositioned Implant Neck and/or Arm Pain Neurological Upper Body 2 Lower Body Non-Union 4 Non-Union Pending Other Pain Respiratory 2 Spinal Event: Cervical Spine Thoracic Spine Lumbar Spine Subsidence Trauma Urogenital Vascular Intra-op Other 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, The most noteworthy adverse events in the AFFINITY device group were neurological complications and spinal events. A total of 5 upper and lower body neurological events occurred in 5 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; event producing leg numbness symptoms; case of hand cramping; Morton s neuroma of the foot; and 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; cervical arthritis; bone spur; thoracic herniated nucleus pulposus and 3 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 4 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 involved hand pain. Of the events occurring between 6 and 2 months postoperatively, 5 involved neck and arm pain, 4 involved shoulder pain including rotator cuff tendonitis, and involved cervical muscle pain and headache. Eleven events occurred at least 2 months after the initial surgery. Of these, 3 involved shoulder pain, 4 involved neck and/or arm pain, involved arm pain associated with fatigue, involved joint pain in neck, shoulders, back, and hands, involved elbow pain, and involved thoracic pain. In addition to the 35 reports of neck/arm pain, Table includes 5 patients who reported hand pain. Of the 5 patients reporting neck/arm/hand pain symptoms, 35 of the complaints could be attributed to the operative or adjacent levels. Of the 5 patients complaining of postoperative neck, arm and hand symptoms, were considered neck pain failures and 7 were considered arm pain failures according to the success/failure criteria. 9 fibromyalgia, hardware removal, hearing loss and cataracts, hepatomegaly, Horner s Syndrome, joint crepitus, low B2 and folate, malpositioned cervical plate, narcotic addiction, psychological disorder, and toothache.

22 Table II presents the Bayesian statistical comparison of adverse events between the AFFINITY device group and the control treatment group. 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 % to 3% 2% to 3% Cancer % to 4% % to 6% Cardio/Vascular 2% to 32% 6% to 52% Carpal Tunnel Syndrome 2% to 7% % to 6% Dural Tear % to 3% % to 6% Dysphonia/Dysphagia 3% to % 2% to 5% Gastrointestinal 6% to 5% % to 9% Graft Site Related 2% to 47% 3% to 54% Implant Displacement / Loosening / Collapse % to 2% 8% to 25% Infection 2% to % % to 2% Malpositioned Implant % to 3% % to 6% Neck and/or Arm Pain 2% to 23% 3% to 6% Neurological 4% to 2% 26% to 53% Non-Union (Outcome Pending) % to 7% 2% to 2% Other Pain 3% to % 2% to 9% Respiratory % to 2% % to % Spinal Event % to 23% 7% to 27% Subsidence % to 3% % to 6% Trauma 5% to 47% 6% to 35% Urogenital % to 7% 3% to 23% Vascular Intraop % to 2% % to 9% Other Adverse Event 5% to 3% 5% to 24% Any Adverse Event 46% to 6% 55% to 8% 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 2-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. TABLE III - SECONDARY SURGICAL PROCEDURES Clinical Comparison of Secondary Surgeries Bayesian Statistical Comparison of Second Surgeries Type of Secondary Surgical Procedure Up to 2 Months ( day to 9 Months) 24 Months or Later (9 Months to 48 Months) Total Events 4 There is a 95% Probability that Second Surgery rates will fall between the following ranges Type of Secondary AFFINITY Surgical Procedure 3 N=78 Control N=5 AFFINITY N=74 Control N=47 AFFINITY Control AAFFINITY Cage System Control Revision % to 3% 6% to 58% Removal % to 6% % to 6% Supplemental Fixation 5 6 % to 6% % to 6% Reoperation % to 4% % to % Other % to 9% 8% to 3% Control, i.e., patients receiving the autograft treatment 2 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. 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 2-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 Death Note: Additional surgery may be necessary to correct some of these potential adverse events. 2

23 CLINICAL RESULTS: STUDY DESIGN AND PURPOSE A 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. METHODS Inclusion 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-T 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 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, 2, 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 5 points if the preoperative score was at least 3 points or by at least 5% if the preoperative score was less than 3 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 ANALYSES The 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 2-month outcomes and the relationship established from patients that had both 2 and 24-month evaluations. PATIENT POPULATION A total of 22 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 5. 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 3% rate for the control patients. RESULTS The adjusted posterior means of success probabilities for the primary effectiveness parameters, including overall success, at 24 months postoperative can be found in Table IV. TABLE IV POSTERIOR MEANS (95% HPD CREDIBLE INTERVALS) OF SUCCESS PROBABILITIES FOR PRIMARY EFFECTIVENESS VARIABLES 24 Months AFFINITY Device Success Rate (Range*) Control Success Rate (Range*) Overall Success 68% (6% to 74%) 6% (48% to 75%) Fusion 94% (63% to 97%) 86% (68% to 99%) NDI Pain/Disability Improvement 75% (68% to 8%) 75% (62% to 87%) Neurological Status Maintenance or Improvement 96% (87% to %) 78% (45% to 92%) * 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, 3 of 7 AFFINITY device patients and 6 of 45 control patients would not be a neurological success. Of the 3 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: STERILIZATION METHODS Method Cycle Temperature Exposure Time Steam Gravity 25 F (2 C) 3 Min. *Steam Gravity 273 F (34 C) 2 Min. Steam Pre-Vacuum 27 F (32 C) 5 Min. * 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 performance 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. IN USA Manager Customer Service Division Medtronic Sofamor Danek USA, Inc. 8 Pyramid Place Memphis, Tennessee 3832 Telephone: or Supplied by Medtronic Sofamor Danek 22 Medtronic Sofamor Danek USA, Inc. All rights reserved IN EUROPE Sofamor SNC** 3, rue de la perdrix 9329 TREMBLAY FRANCE Telephone: (33) **authorized representative 2

24 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. MEDTRONIC SOFAMOR DANEK USA, INC. Spinal Division Worldwide Headquarters 8 Pyramid Place Memphis, TN 3832 (9) (8) Customer Service: (8) For more information go to MLITAFFST5A5 IRN23/5 25 Medtronic Sofamor Danek USA, Inc. All Rights Reserved.