SILO Spinal System TSRH. Surgical Technique. as described by:

Transcription

1 TSRH Surgical Technique SILO Spinal System as described by: Marcel F. Dvorak, M.D., FRCSC Combined Neurosurgical and Orthopaedic Spine Program Vancouver General Hospital Associate Professor Department of Orthopaedics University of British Columbia Charles G. Fisher, M.D., MHSc, FRCSC Combined Neurosurgical and Orthopaedic Spine Program Vancouver General Hospital Assistant Professor Department of Orthopaedics University of British Columbia Rick C. Sasso, M.D. Indiana Spine Group Assistant Professor Clinical Orthopaedic Surgery Indiana University School of Medicine Indianapolis, Indiana Christopher I. Shaffrey, M.D., FACS Professor of Neurological Surgery Adjunct Professor Orthopaedic Surgery University of Virginia Charlottesville, Virginia Daniel J. Sucato, M.D., M.S. Staff Orthopaedic Surgeon Texas Scottish Rite Hospital Associate Professor Department of Orthopaedic Surgery University of Texas at Southwestern Medical Center Dallas, Texas Jeffrey C. Wang, M.D. Chief, Orthopaedic Spine Service Associate Professor Orthopaedic and Neurosurgery UCLA Comprehensive Spine Center UCLA School of Medicine Santa Monica, California

2 Table of Contents Preface Features and Benefits Biomechanical Testing Implant Overview Instruments NIM-SPINE Neural Integrity Monitor System Pedicle Preparation Screw Placement Trauma T12 Burst Fracture Case T12 to L1 Fracture Dislocation Case Deformity Double Major Curve Correction Case Kyphosis Correction Case Degenerative L4 to S1 Fixation Case L5 Spondylolisthesis Reduction Case Implant Explantation Product Ordering Information Important Product Information

3 Preface Dear Colleagues: Despite the introduction and evolution of a wide variety of thoracolumbar rod and screw systems, the spine surgeon still faces many challenges in the operative care of patients requiring segmental spinal instrumentation for trauma, deformity, tumor, and major degenerative instabilities. The ability of ONE thoracolumbar rod and screw system to safely manipulate spinal segments, reduce the rod to the screw or hook in a controlled manner, and correct significant deformities while maintaining strong implant/bone fixation has been lacking. We believe that the TSRH SILO 5.5 Spinal System provides spine surgeons with a posterior fixation system with biomechanically-proven strength, flexibility, and ease of use, thus enabling the surgeon to efficiently deal with the severest of spinal pathology. The side-opening and top-tightening aspects of the TSRH SILO 5.5 Spinal System screws and hooks are designed primarily to simplify and enhance reduction capability in the high-demand situation where deformity, due to trauma or other etiologies, provides significant reduction and fixation difficulties. Furthermore, we believe that the single-handed operation of the Rock-N- Roll Reducer and the flexibility of the Sagittal Adjusting Screw will facilitate the intraoperative reduction of the screw to the rod and will minimize the stresses that occur at the screw/bone interface during these reduction maneuvers. We are optimistic and excited about the simplicity, versatility, and innovative capabilities of this new system that is targeted to provide intraoperative benefits to both the surgeon and the patient. It is our sincere hope that as we have, you will also be able to experience these benefits. Sincerely, Marcel F. Dvorak, M.D., FRCSC Charles G. Fisher, M.D., MHSc, FRCSC Rick C. Sasso, M.D. Christopher I. Shaffrey, M.D., FACS Daniel J. Sucato, M.D., M.S. Jeffrey C. Wang, M.D. 2

4 Features and Benefits Sagittal Adjusting Screw (SAS) - Enables 25 sagittal angulation - Provides the strength and manipulation capability of a Fixed Angle Screw with the forgiveness of a Multi Axial Screw - Allows for screw positioning and rod insertion at challenging angles - Sagittal forgiveness reduces the stress on the bone/screw interface that occurs during correction maneuvers and rod seating (i.e., the windshield wiper effect) Rod Reduction Capabilities - Simplification of rod/screw reduction even over large trajectories - Single-hand operated Rock-N-Roll Reducer effortlessly reduces the rod to the screw or hook, thus enabling dorsal and lateral reduction - Allows vertebral segment manipulation and provisional fixation by a single surgeon Provisional Rod Capture - Single closure mechanism captures the rod into the head of the implant while still allowing for screw/vertebral body manipulation (derotation at the apex of scoliosis and kyphosis correction) - Set Screws can be preloaded, therefore eliminating the possibility of cross-threading during rod capture 3

5 Biomechanical Testing 4,000 Axial Grip 3,500 3,455 3,361 3,668 3,000 3,075 2,500 Load (N) 2,000 1,500 1,750 1,668 1,480 2,239 1, TSRH SILO System Fixed Angle Screw (Ti) TSRH SILO System Multi Axial Screw (Ti) TSRH SILO System Sagittal Adjusting Screw (Ti) MOSS MIAMI System (Ti) SILHOUETTE System (Ti) XIA System (Ti) CLICK-X System (Ti) SR-90 System (Ti) Interconnection Fatigue Runout Moment (Nm) TSRH SILO System Multi Axial Screw (Ti) TSRH SILO System Sagittal Adjusting Screw (Ti) MOSS MIAMI System (Ti) SILHOUETTE System (Ti) XIA System (Ti) CLICK-X System (Ti) SR-90 System (Ti) 1,600 Static Flexion/Extension 1,400 1,384 1,200 1,000 Load (N) TSRH SILO System Multi Axial Screw (Ti) TSRH SILO System Sagittal Adjusting Screw (Ti) MOSS MIAMI System (Ti) SILHOUETTE System (Ti) XIA System (Ti) CLICK-X System (Ti) SR-90 System (Ti) 4 TSRH SILO System is a trademark of Medtronic Sofamor Danek. The other products are third party trademarks and their use is not intended to communicate any license, sponsorship, or affiliation.

6 Implant Overview Versatility Multiple implant types provide versatility when planning surgical treatment as well as intraoperative flexibility to accommodate varying patient anatomy and pathologies Implant saddles are color-coded by screw diameter. Color-Coding Reference Sagittal Adjusting Screw 4.5mm 5.0mm 5.5mm 6.5mm 7.5mm 8.5mm Implant crowns are color-coded by screw diameter. Color-Coding Reference Multi Axial Screw 4.5mm 5.0mm 5.5mm 6.5mm 7.5mm 8.5mm 5.5mm Precut Precontoured Rod, Titanium Alloy Set Screw 25cm Rod, Titanium Alloy Lateral Connector Fixed Angle Screw 50cm Lined Rod, Titanium Alloy 5

7 Implant Overview Hook Color-Coding Reference Right-hand Hooks* magenta Left-hand Hooks* blue *Based on medial rod placement Hook Type Placement Blade Direction Regions of the Spine Design Features Thoracic Hook Lamina T1 to T10 Hook throat ramp prevents the blade from encroaching into the spinal canal. Pedicle Hook Articular Process T1 to T10 Bifid blade grasps the thoracic pedicle for increased stability. Shoe design provides stable fit to the lamina/pedicle. Laminar Hook Lamina Transverse Process T1 to L5 T1 to L5 Blade geometry designed to better fit the lumbar lamina to prevent hook pullout. Wider blade width distributes forces evenly over a wider aspect of the bone. Narrow Laminar Hook Lamina Transverse Process T1 to L5 T1 to L5 Narrower blade width minimizes metal volume in the spinal canal. Elevated Laminar Hook Lamina Transverse Process T1 to L5 T1 to L5 Can correct anatomic malalignment between two laminae in the dorso/ventral plane. Designed to allow the implant to be placed closer to the midline. Lateral Offset Hook Lamina T1 to L5 Can be used to medialize or lateralize the rod in supralaminar or infralaminar positions. Can Transverse Process T1 to L5 back up a pedicle screw at the same level. 6

8 Instruments Screw Preparation Awl ( ) Thoracic Probe, Curved ( ) Lumbar Probe, Straight ( ) Dual Ended Feeler Probe ( ) Feeler Probe ( ) Cannulated Ratcheting Handle ( ) Solid Tap, 4.5mm ( ) Solid Tap, 5.5mm ( ) Solid Tap, 6.5mm ( ) Solid Tap, 7.5mm ( ) 7

9 Instruments Screw Placement, Adjustment Manipulation Stick ( ) Fixed Angle Screwdriver* ( ) Sagittal Adjusting Screwdriver* ( ) *These drivers are interchangeable, unless utilizing image guidance technologies. Multi Axial Screwdriver ( ) Multi Axial Screw Height Adjuster ( ) Screw Positioner ( ) 8

10 Instruments Rod Manipulation 20" Rod Template ( ) Rocker Reducer ( ) Medial Corkscrew ( ) Rod Pusher ( ) Rock-N-Roll Reducer, Long, Left ( ) Rock-N-Roll Reducer, Long, Right ( ) Rock-N-Roll Reducer, Short, Right ( ) Rock-N-Roll Reducer, Curved, Right ( ) 9

11 Instruments Rod Manipulation Rod Gripper ( ) Rod Inserter ( ) In Situ Bender, Left ( ) In Situ Bender, Right ( ) Coronal Plane Bender, Left ( R) Coronal Plane Bender, Right ( R) Rod Rotation Wrench ( ) French Bender ( ) 10

12 Instruments Tightening Dual Ended Set Screw Starter ( ) Dual Ended Set Screw Starter with Stops ( ) Provisional T25 Driver ( ) Extra Long Provisional T25 Driver ( ) 11

13 Instruments Tightening Quick Connect T25 Driver Shaft ( ) 90 in-lb Torque Limiting Driver ( ) Top View Top View Multi Axial Counter Torque ( ) Fixed Angle/Sagittal Adjusting Counter Torque ( ) Compression/Distraction Parallel Compressor, Small ( ) Parallel Compressor, Large ( ) 12 Distractor, Parallel ( ) Distractor, Curved ( )

14 Instruments Hook Placement Pedicle Hook Trial ( ) Laminar Hook Trial ( ) Hook Holder ( ) Side Hook Pusher ( ) Short Provisional Driver ( ) Corkscrew Reducer ( ) Corkscrew Reducer ( ) and Hook Holder ( ) assembled 13

15 NIM-SPINE Neural Integrity Monitor System When using EMG neuromonitoring to evaluate screw placement, it is important that the probe is in contact with the implant head when using Fixed Angle and Sagittal Adjusting Screws. The probe should have direct contact with the bone screw when using Multi Axial Screws. Stim-Controlled Ball Tip Probe ( ) 23cm Ball Tip Probe, Long Length ( ) 2.3mm Ball Tip Probe, Standard Length ( ) Straight Pedicle Probe ( ) 14 Thoracic Pedicle Probe ( ) Lumbar Pedicle Probe ( )

16 Pedicle Preparation Identify the appropriate anatomical landmarks for creating the entry points for the pilot holes for screw insertion (Figure 1). Pilot holes are then created with a sharp awl or burr, depending on surgeon preference (Figure 2), and then followed by either a Thoracic or Lumbar Ball Handled Probe (Figure 3). Figure 1 Figure 2 In the thoracic spine the medial aspect of the transverse process can be removed with a Ronguer to provide local bone graft, as well as best accommodate full seating of the implant. Figure 3 15

17 Pedicle Preparation Alternatively, a NIM-SPINE System Thoracic or Lumbar Probe can be used to create the hole (Figure 4). Triggered EMG monitoring can be performed during the advancement of the probe into the pedicle to ensure proper placement. Prior to insertion into the pedicle, the NIM-SPINE System Probe should be electrified to 8-10mA. Using a Feeler Probe, the pedicle walls are palpated to check for any perforations. Check to the base (floor) of the hole to confirm five distinct bony borders: a floor and four walls (medial, lateral, superior, and inferior) (Figure 5). The depth of the pedicle hole can also be gauged by utilizing the Feeler Probe (Figure 6). At this point, most surgeons would obtain radiographic confirmation of trajectory. Blood loss can be minimized while obtaining radiographs by adding a ball of bone wax to the mid-shaft of the pedicle marking instrument and then inserting it so the wax prevents bleeding from the probed pedicle hole. Figure 4 Figure 5 Figure 6 16

18 Pedicle Preparation The TSRH SILO System screws have a self-tapping flute making separate tapping necessary only in exceptionally sclerotic bone, or when the screw requires extra encouragement to take an insertion path in a specific direction; for example, either in an extremely large pedicle or a small one with a deficient lateral wall. Some surgeons prefer to use a tap smaller than the screw diameter for enhanced screw purchase. The instrument set contains taps ranging from 4.5mm to 7.5mm, which correspond to the pedicle screw diameters. The selected diameter tap is advanced to the waist of the pedicle and may not need to be advanced completely into the vertebral body (Figure 7). Figure 7 17

19 Screw Placement Once the appropriate screw length has been chosen by a combination of preoperative and intraoperative measurements, the dimensions of the selected screw can be confirmed and the implant attached to the screwdriver. The Fixed Angle Screws and Sagittal Adjusting Screws utilize the Manipulation Stick for screw insertion. The Set Screws should be preloaded into the head of the implant prior to attachment to the Manipulation Stick. The green markings on the Manipulation Stick indicate the direction of the implant rod channel opening. With the Cannulated Quick Connect Ratcheting Handle preloaded on the Manipulation Stick, attach the tip of the Manipulation Stick to the implant head and slide the sleeve on the Manipulation Stick toward the implant to secure the implant in the instrument (Figure 8). Once the screw is secured to the Manipulation Stick, the rigidity between the implant and instrument may be maximized by inserting the Extra Long Provisional T25 Driver through the cannulated shaft of the Ratcheting Handle and Manipulation Stick and backing up the Set Screw (Figure 9). This step will also ensure that the Set Screw is clear of the rod channel. Figure 8 Figure 9 18 When utilizing Fixed Angle Screws and Sagittal Adjusting Screws in combination with the Manipulation Stick, the Set Screws should be preloaded into the implants on the back table for intraoperative efficiency.

20 Screw Placement In cases where image guidance is used, the Fixed Angle Screwdriver and Sagittal Adjusting Screwdriver may be used in place of the Manipulation Stick (Figure 10). The Multi Axial Screws attach directly to the Multi Axial Screwdriver, prior to insertion of the Set Screw (Figure 11). Figure 10 Figure 11 19

21 T12 Burst Fracture Case The following technique describes multi-level fixation of an unstable T12 burst fracture. T12 BURST FRACTURE CASE TRAUMA The recommended technique for posterior fixation of an unstable T12 burst fracture requires Fixed Angle and/or Sagittal Adjusting Screw fixation at two motion segments above and one or two motion segments below the fractured vertebra. If motion segment sparing is an issue, such as in the lumbar spine, a Lateral Offset Hook can be used to supplement the screw when only one motion segment below the fracture is instrumented (Figure 12). We recommend that Fixed Angle Screws be used at the caudal motion segments, while Sagittal Adjusting Screws should be placed at the two rostral levels. The Sagittal Adjusting Screws will accommodate rod seating, allow kyphosis correction, and will minimize stresses that would be incurred at the bone/screw interface than if only Fixed Angle Screws were used (Figure 13). Figure 12 Figure Although the use of Fixed Angle Screws below and Sagittal Adjusting Screws above the injury is the standard approach, Sagittal Adjusting Screws could be utilized at all levels. Additionally, if the pedicle anatomy or coronal plane alignment dictates, the Multi Axial Screw could be used in the caudal segments.

22 T12 Burst Fracture Case Intraoperative radiographs or fluoroscopy may be used to assist in the verification of appropriate screw position (Figure 14). The ideal screw length measures at least 80% of the depth of the vertebral body, except in S1 where anterior cortical perforation is preferred. Intraoperative EMG monitoring utilizing the NIM-SPINE System Neural Integrity Monitor may also be used if available. T12 BURST FRACTURE CASE TRAUMA Figure 14 21

23 T12 Burst Fracture Case T12 BURST FRACTURE CASE TRAUMA Once the screw is fully seated into the pedicle, the instrument sleeve can be disengaged from the screw and the instrument removed, if desired. However, the Manipulation Sticks may be left in place after the screws are inserted successfully on one side, thus guiding the surgeon, assistant, resident, or fellow during probing and insertion of the contralateral screws (Figure 15). To verify proper placement of the screw, the NIM-SPINE System Stim-Controlled Ball Tip Probe or the Standard Ball Tip Probe can be used to test the screw (Figure 16). Figure 15 Figure 16 22

24 T12 Burst Fracture Case Once correct screw placement has been confirmed radiographically, determine the length and contour of the rod by utilizing the Rod Template (Figure 17). The rods can then be cut and contoured in the sagittal and coronal planes to the normal and desired contour of the spine, which is relatively straight in the thoracolumbar region. Clamping the rod with Rod Grippers at both ends of the rod helps prevent the rod from rotating during the contouring process. T12 BURST FRACTURE CASE TRAUMA Figure 17 Resection or scoring of the facet joints to be fused, and decortication of the posterior elements should be performed just prior to rod insertion. In trauma cases, local bone graft harvested from the posterior elements is often adequate for fusion. In some cases, the most rostral and caudal motion segments may be instrumented without fusion, with the goal of removing the instrumentation once fusion has occurred, (usually at six to nine months postoperative). A technically excellent fusion is a critical, and often forgotten, aspect of this procedure. 23

25 T12 Burst Fracture Case T12 BURST FRACTURE CASE TRAUMA Utilizing the Rod Inserter, insert the contoured rod first into the caudal end of the construct and secure the Set Screws (Figure 18). This will allow for segmental correction and restoration of lordosis at the superior (rostral) levels. If additional dorsal height adjustment is needed, the Screw Positioner may be utilized (Figure 19). Figure 18 Figure The Screw Positioner may be used to quickly align the screw heads, or even advance a screw by one full rotation without attaching the Manipulation Stick. The smooth contour of the implants will allow the screws to be seated into the bone, decreasing prominence and facilitating dorsal height adjustment.

26 T12 Burst Fracture Case For rod seating into the head of the superior (rostral) implants, multiple reduction options are available to achieve the desired sagittal plane correction. The Rock-N-Roll Reducer is the preferred instrument for all rod/screw reduction, even the simplest ones. To use the Rock-N-Roll Reducer, position the reducer so that the handles are 90 to the rod and grasp the screw head from above. The protrusions on the tip of the reducer should engage with the divots on the implant. Once attached to the implant, rock the instrument as needed to capture the rod and deliver it to the screw. The handles of the reducer can then be slowly compressed until the rod is fully seated into the implant (Figure 20). The T25 Provisional Driver is then used to advance and tighten the Set Screw (Figure 21). T12 BURST FRACTURE CASE TRAUMA Figure 20 Figure 21 In areas of the spine where soft tissue may contact the instruments, the Curved Rock-N-Roll Reducer may be used to avoid impingement. 25

27 T12 Burst Fracture Case T12 BURST FRACTURE CASE TRAUMA When a minimal amount of reduction is required, the Rocker Reducer can be used to reduce the rod into the head of the pedicle screw. Grasp the back of the screw head with the rocker, ensuring that the rocker cam is positioned above the rod. The rocker is then pushed medially, thus levering the rod into the screw head (Figure 22). The T25 Provisional Driver is then used to advance and tighten the Set Screw (Figure 23). Once the correcting rod has been placed and desired sagittal alignment achieved, the stabilizing rod should now be placed on the contralateral side. Alternatively, the surgeon and assistant can both perform the reduction synchronously on the right and left using two Rock-N-Roll Reducers, thus distributing the forces to both sides. Occasionally, the thoracic interpedicular distance is narrower than the lumbar interpedicular distance, requiring some in situ coronal plane rod bending. This is ideally performed with the Coronal Plane Benders (Figure 24). In this situation, by opening the cephalad two screws medially, and the caudal two screws laterally, a straight rod may be used. Figure 22 Figure Figure 23

28 T12 Burst Fracture Case Once the major reduction has been accomplished, fine adjustments may be made by applying either compression or distraction and kyphosis correction as needed. In either maneuver, the Set Screw on one side of the motion segment should be provisionally tightened, with the Set Screw loose in the implant to be compressed or distracted. Compression or distraction will occur against the provisionally tightened implant (Figure 25). The T25 Provisional Driver may be used to temporarily lock and secure the rod and implant construct. If necessary, the Rod Gripper may also be utilized as a point of fixation against which to distract or compress. Note the availability of both Large-span and Short-span Compressors in the instrument set (Figure 26). T12 BURST FRACTURE CASE TRAUMA Figure 26 Figure 25 27

29 T12 Burst Fracture Case T12 BURST FRACTURE CASE TRAUMA Minor adjustments to kyphosis may be made by applying the Manipulation Stick with the T25 Provisional Driver. Sagittal manipulation may be applied to correct kyphosis and then tighten the Set Screws to lock this sagittal angulation in place (Figure 27). To prevent compression during this maneuver, a Rod Gripper may be placed adjacent to the screw. When all implants are securely in place, final tightening of the Set Screws may be accomplished. First, attach the Torque Limiting Driver to the Quick Connect T25 Driver Shaft. This assembly can then be inserted into the cannulated portion of the Counter Torque. Position the Counter Torque and Final Driver onto the implant head, so that the arrows on the Counter Torque handle are pointing in the direction of the rod opening. This will provide a secure fit between the instrument and implant. Ensure the driver is fully inserted into the Set Screw and turn the handle clockwise. An audible click is heard from the driver when optimal torque is achieved (approximately 90 in-lb) (Figure 28). Each additional Set Screw can then be secured. Figure 28 Figure 27 28

30 T12 Burst Fracture Case An X10 CROSSLINK Plate may now be attached to the construct for increased torsional stability. The correct size plate is determined by using the X10 CROSSLINK Measuring Caliper to measure the span between the rods. Once the X10 CROSSLINK Plate has been placed on the rods and is in its final position, the Set Screws can be advanced and tightened. The final construct (Figure 29) should be verified by X-ray or fluoroscopy prior to closing (Figure 30). T12 BURST FRACTURE CASE TRAUMA Figure 30 Figure 29 29

31 T12 to L1 Fracture Dislocation Case T12 TO L1 FRACTURE DISLOCATION CASE TRAUMA The following technique describes multi-level fixation of a T12 to L1 fracture dislocation. Open reduction and segmental fixation of a fracture dislocation requires major vertebral body manipulations that result in the reduction of kyphosis and correction of anterior translation. The TSRH SILO Spinal System is designed to enable the surgeon to perform this maneuver in a controlled fashion, without excessive manipulation, while facilitating careful observation of the spinal canal contents during the reduction maneuver. A fracture dislocation is no place for short segment instrumentation. At least two, and probably three, intact vertebrae must be used for fixation both rostral and caudal to the fractured levels. Due to the magnitude of correction needed, we recommend that Sagittal Adjusting Screws be used both at the rostral and caudal two motion segments surrounding the dislocated level. Leaving the Manipulation Sticks attached to the implants after screw insertion will facilitate the orientation of all screws perpendicular to the laminae of the vertebrae being instrumented (Figure 31). Figure The screws selected for the caudal segments can be Fixed Angle Screws, Sagittal Adjusting Screws, or Multi Axial Screws depending upon the anatomy and coronal plane alignment as previously described. However, Sagittal Adjusting Screws should be utilized in the rostral segments.

32 T12 to L1 Fracture Dislocation Case Once the rod is cut, contoured, inserted into the caudal end of the construct and secured, the magnitude of correction needed becomes apparent. Typically, three types of scenarios may be encountered. The first situation is where the translational and/or kyphotic deformity magnitude is within the excursion of the Rock-N-Roll Reducer. If this is the case, a simple threedimensional reduction can be carried out, as previously described in the scenario of the Burst Fracture. Position the Rock-N-Roll Reducer so that the handles are 90 to the construct, and grasp the screw head from above. Either one or two Rock-N-Roll Reducers can be utilized, synchronously on the right and left sides, or one after the other. The second possible scenario is where there is impaction or locking at the fracture site, which requires distraction prior to the translational reduction. This can be accomplished by placing the Rod Gripper on the rod, just caudal to where the rod will be reduced into the screw. Next, capture the rod with the Rock-N-Roll Reducer (Figure 32). T12 TO L1 FRACTURE DISLOCATION CASE TRAUMA Figure 32 31

33 T12 to L1 Fracture Dislocation Case T12 TO L1 FRACTURE DISLOCATION CASE TRAUMA Distraction can then be applied between the Rod Gripper and the Rock-N-Roll Reducer (i.e., the tongs that are holding the rod) to unlock the fracture and proceed with the threedimensional reduction. With the Distractor in one hand and the Rock-N-Roll Reducer in the other hand, the rod can then be delivered down into the opening of the screw head in a controlled fashion (Figure 33). The third scenario is the situation where there is a severe translational injury and the reduction required is beyond the excursion of the Rock-N-Roll Reducer. The Manipulation Sticks, assembled to the Cannulated Ratcheting Handles, can be secured bilaterally to the rostral screws. A manual open reduction of the fracture can then be carried out by gently manipulating the handles on the Manipulation Stick. Following each of these scenarios, the Set Screw is then provisionally tightened utilizing the Provisional T25 Driver. The rod can then be reduced into the subsequent screws and final tightening accomplished. Where the Rock-N-Roll Reducer is attached to the rod, distraction can be applied between the open reducer and the Rod Gripper to unlock the fracture. Figure 33 32

34 T12 to L1 Fracture Dislocation Case An X10 CROSSLINK Plate may now be attached to the construct for increased stability. The final construct should be verified by X-ray or fluoroscopy prior to closing (Figure 34). T12 TO L1 FRACTURE DISLOCATION CASE TRAUMA Figure 34 33

35 Double Major Curve Correction The following technique describes the correction of a Double Major Curve from T4 to L3 (Figures 35a and 35b) utilizing hooks, Fixed Angle Screws and Sagittal Adjusting Screws. DOUBLE MAJOR CURVE CORRECTION D EFORMITY The TSRH SILO Spinal System screws can be utilized in the thoracic spine, and are designed to provide the ability to correct the three-dimensional deformity and offer greater postoperative maintenance of the correction. Hooks may be utilized in the uppermost end of the construct for adjacent level preservation. For maximum correction and intraoperative flexibility, Fixed Angle Screws are most often used in the thoracic aspect of the construct to allow for optimal coronal plane, sagittal plane and axial plane correction. Sagittal Adjusting Screws are best utilized in the lumbar region to facilitate rod seating and minimize stress otherwise incurred at the bone/screw interface. Multi Axial Screws may also be utilized at the caudal levels of the construct as necessary and may be especially important when there is significant lordosis or lateral translation differences at adjacent levels. 34 Figure 35a Figure 35b

36 Double Major Curve Correction Careful selection of anchor points to the spine is necessary when performing deformity correction. The TSRH SILO Spinal System provides versatility by supplying multiple implant types, offering the surgeon the option of utilizing hooks or screws or a combination (hybrid) for correction of all curve patterns. A typical hybrid construct is shown below (Figure 36) in which hooks are used for the thoracic deformity while pedicle screws are used at the base of the construct. Figure 37 demonstrates a typical all-pedicle screw pattern in which segmental fixation is achieved for the correcting rod (left rod), while the right rod has strategically-placed screws to achieve the goals of stable fixation (Figure 37). DOUBLE MAJOR CURVE CORRECTION D EFORMITY Figure 36 Figure 37 35

37 Double Major Curve Correction Hook Site Preparation/Placement Pedicle Hooks may be placed from T1 to T10. The inferior facet is removed in a square fashion using an osteotome. The Pedicle Hook Trial is then used to clear the correct path for the Pedicle Hook (Figure 38). Once the Pedicle Hook has been attached to the Hook Holder, the Side Loading Hook Pusher can then engage the Pedicle Hook simultaneously (Figure 39). A mallet can then be used to fully seat the Pedicle Hook. After the hook has been seated, it should be tested to ensure that it has excellent translational stability. DOUBLE MAJOR CURVE CORRECTION D EFORMITY Laminar Hooks can be utilized at the transverse processes. The Laminar Hook Trial is used to clear soft tissue and periosteum of the transverse process and the Hook Holder is then utilized to place this wide-blade hook into the correct position. Often, these hooks are not fully secure and need to be removed until just prior to placement of the rod. The Thoracic Hook can be placed in the sublaminar position following partial removal of the spinous process and ligamentum flavum. Care should be taken during preparation of the hook site to not remove too much lamina in order to prevent weakening of the hook connection to the spine. Utilizing the Hook Holder, these hooks should be placed just prior to seating of the rod in order to prevent movement of the hook shoe within the spinal canal. Figure 38 Figure 39 36

38 Pedicle Screw Placement Double Major Curve Correction The pedicle screws are sequentially inserted into the vertebral body, using intraoperative imaging (either fluoroscopy, intraoperative CT or posteroanterior and lateral plane radiographs) to evaluate the position of the screws in two planes, either during or following the screw placement. Additionally, intraoperative EMG monitoring utilizing the NIM-SPINE System Neural Integrity Monitor may be used if available (Figure 40). Once the screw is inserted and aligned, the instrument sleeve is disengaged from the screw and the instrument removed. To verify proper placement of the screw, the NIM-SPINE System Stim-Controlled Ball Tip Probe or the Standard Ball Tip Probe may be used to test the screw. When using triggered EMG neuromonitoring to evaluate screw placement, it is important that for the Fixed Angle and Sagittal Adjusting Screws the probe is in contact with the implant head. For Multi Axial Screws, the probe should contact the bone screw directly (Figure 41). DOUBLE MAJOR CURVE CORRECTION D EFORMITY Figure 40 Figure 41 Fixed Angle Screw Sagittal Adjusting Screw Multi Axial Screw 37

39 Rod Contouring Double Major Curve Correction Determining the length and contour of the rod is facilitated by utilizing the Rod Template (Figure 42). The rods can then be measured and contoured in the sagittal (and if needed) the coronal planes to the normal and desired contour of the spine. The long rods have two orientation lines positioned on opposite sides of the rod that serve as a reference point during contouring and manipulation. Clamping the rod with Rod Grippers at both ends helps prevent the rod from rotating during contouring (Figure 43). DOUBLE MAJOR CURVE CORRECTION D EFORMITY Figure 42 Figure 43 38

40 Double Major Curve Correction Rod Insertion Position the contoured rod parallel to the side opening of the screws utilizing the Rod Inserter, inserting the rod first into one end of the construct (most common to start at the distal end) (Figure 44). The Set Screws can be advanced slightly to provisionally capture the rod into the head of the implants. If additional dorsal height adjustment is needed, the Screw Positioner may be utilized. The Rod Gripper or Rod Inserter may be used to assist in seating the rod. DOUBLE MAJOR CURVE CORRECTION D EFORMITY Figure 44 39

41 Rod Reduction Double Major Curve Correction For rod seating into the head of the rostral implants, multiple reduction options are available to achieve the desired sagittal and coronal correction. The Rock-N-Roll Reducer is the preferred instrument for reduction, providing an excellent tool for sagittal and coronal plane reduction of the rod. To use the Rock-N-Roll Reducer, position the reducer so that the handles are 90 to the rod and grasp the screw head from above. The instrument is then rocked either medial or lateral as needed to capture the rod. The handles of the reducer can then be slowly compressed until the rod is fully seated into the implant. Simultaneous gentle rocking of the reducer may be necessary to achieve complete seating of the rod into the channel. The Provisional T25 Driver is then used to advance and tighten the Set Screw. DOUBLE MAJOR CURVE CORRECTION D EFORMITY When a minimal amount of reduction is required, the Rocker Reducer can be used to reduce the rod into the head of the implant. Grasp the back of the screw head with the rocker, ensuring that the rocker cam is positioned above the rod. The rocker is then pushed forward toward the rod, levering the rod into the screw head (Figure 45). The T25 Provisional Driver is then used to advance and tighten the Set Screw. Figure 45 40

42 Compression/Distraction Double Major Curve Correction Once the contoured rod has been seated and the Set Screws provisionally tightened, several deformity correction maneuvers can be performed. The rod can be rotated using two Rod Grippers, applying gentle pressure along the right thorax and left flank. Additionally, the rod may be rotated utilizing the Rod Rotation Wrench applied to the hexagonal end of the rod. If hooks are used, careful inspection of the hooks is necessary to identify hooks backing up with rod rotation. The Set Screws should be provisionally tightened to prevent rod derotation and to ensure the rod is fully seated in all hooks and screws. If either compression (on the convex side) or distraction (on the concave side) is needed, it should be performed at this time. In either maneuver, the Set Screw on one side of the motion segment should be provisionally tightened, with the Set Screw loose in the implant to be compressed or distracted. Compression or distraction will occur against the provisionally tightened implant. If necessary, the Rod Gripper may also be utilized as a point of fixation against which to distract or compress. The T25 Provisional Driver may then be used to temporarily lock and secure the rod and implant construct (Figure 46). DOUBLE MAJOR CURVE CORRECTION D EFORMITY Figure 46 41

43 Double Major Curve Correction Deformity Correction In situ bending for residual coronal or sagittal deformity is now performed using the In Situ Benders or Coronal Plane Benders, respectively. Finally, with the Manipulation Sticks attached to the apical screws, derotation and sagittal adjustments can be performed and then fixed by advancing the Set Screw with the Provisional T25 Driver. Once the correcting rod has been placed and the desired sagittal and coronal alignment achieved, the stabilizing rod may now be inserted into the contralateral side. DOUBLE MAJOR CURVE CORRECTION D EFORMITY Incremental lateral translation may be facilitated by using Lateral Connectors to gradually translate the rod into a hook or screw. With the rod in place, a Lateral Connector can easily be removed and converted to a direct connection to the screw by rotating the screw 90º, allowing it to accommodate the rod. 42

44 Double Major Curve Correction Final Tightening When all implants are securely in place, final tightening of the Set Screw may be accomplished. First, attach the Torque Limiting Driver to the Quick Connect T25 Driver Shaft. This assembly can then be inserted into the cannulated portion of the Counter Torque. The driver should be first positioned into the Set Screw to ensure complete seating. Next, position the Counter Torque onto the implant head, so that the arrows on the Counter Torque handle are pointing in the direction of the rod opening. This will ensure a secure fit between the instrument and implant (Figure 47). Turn the handle of the driver clockwise until the optimal torque is achieved (approximately 90 in-lb) and an audible click is heard from the driver. Each additional Set Screw can then be secured. DOUBLE MAJOR CURVE CORRECTION D EFORMITY Figure 47 43

45 Final Construct Double Major Curve Correction An X10 CROSSLINK Plate (shown in Figure 29) may now be attached to the construct for increased torsional stability. The correct size plate is determined by using the X10 CROSSLINK Measuring Caliper to measure the span between the rods. Once the X10 CROSSLINK Plate has been placed on the rods and is in its final position, the Set Screws can be advanced and tightened. The final construct should be verified by X-ray or fluoroscopy prior to closing to ensure that the desired sagittal plane correction is achieved (Figures 48a and 48b). DOUBLE MAJOR CURVE CORRECTION D EFORMITY 44 Figure 48a Figure 48b

46 Kyphosis Correction Case The following technique describes Scheuermann s thoracic kyphosis correction from T2 to L3. Kyphosis correction takes advantage of the unique capabilities of the screws available with the TSRH SILO Spinal System. The three screw types, Fixed Angle, Sagittal Adjusting and Multi Axial, allow for great versatility and outstanding correction of sagittal plane deformity. Especially important is the Sagittal Adjusting Screws, which permit 25 of sagittal angulation with sequential, segmental correction. The exact technique will depend on both the severity and etiology of the deformity. Some modification of the surgical procedure may occur depending if the etiology is Scheuermann s kyphosis, congenital malformation or a post-traumatic condition. An individual case (particularly with severe or rigid sagittal deformity) may require an anterior release with or without structural grafting. Posterior Smith-Petersen or chevron-type osteotomies are necessary at the apex of the kyphotic deformity. Each of these cases will require a multi-segmental posterior instrumentation procedure. KYPHOSIS CORRECTION CASE D EFORMITY 45

47 Kyphosis Correction Case The typical construct for a Scheuermann s kyphosis spans the entirety of the kyphotic deformity, and extends to the onset of the lumbar lordosis. On average this would extend from T2, proximally, to the first lordotic disc distally. A typical construct would utilize either proximal hooks and distal screws or an all-screw construct. In general, the transverse processes are stout and strong in Scheuermann s kyphosis and offer an excellent attachment point for hooks. A typical hook construct proximally would engage these transverse processes in a downgoing position and an alternating pattern. For example, beginning at T2 on the left side, downgoing Laminar Hooks would be placed at the transverse processes of T2, T4, T6, T8 and T10. Similarly on the right side, downgoing Laminar Hooks would be placed at the transverse processes of T3, T5, T7 and T9. Bilateral pedicle screws would then be utilized at T12 through L3, assuming L2-L3 is the first lordotic disc (Figure 49). KYPHOSIS CORRECTION CASE D EFORMITY Figure 49 46

48 Kyphosis Correction Case An all screw pattern may also be utilized. When all screws are used, the Fixed Angle Screws or Sagittal Adjusting Screws are best utilized in the thoracic spine, and Sagittal Adjusting Screws in the lumbar spine. This will best accommodate the desired rigid fixation and rod seating capabilities necessary for this type of correction. The pedicle screws are sequentially inserted into the vertebral body, using intraoperative posteroanterior and lateral plane radiographs to evaluate the position of the screws in two planes, either during or following the screw placement. Once the screw is inserted, the instrument sleeve is disengaged from the screw and the instrument removed. To verify proper placement of the screw use the NIM-SPINE System Stim-Controlled or the Standard Ball Tip Probe to test the screw (Figure 50). Frequently, wide facetectomies with or without chevron-type osteotomies are performed to accentuate deformity correction and reduce stresses on the spinal implants during rod placement. Figure 50 KYPHOSIS CORRECTION CASE D EFORMITY 47

49 Kyphosis Correction Case Determining the length and contour of the rod is facilitated by utilizing the Rod Template. If significant kyphosis correction and compression will be performed, the rod will eventually be shorter than initially anticipated. The rods can then be measured and contoured in the sagittal and (if needed) the coronal planes to the normal and desired contour of the spine. The long rods have an orientation line that serves as a reference point in order to facilitate appropriate contouring. Clamping the rod with Rod Grippers at both ends helps prevent the rod from rotating during contouring. Position the contoured rod parallel to the side opening of the screws utilizing the Rod Inserter, inserting the rod first into the distal end of the construct and sequentially introduce the rod into the screw heads approaching the apex of the kyphosis (Figure 51). The second rod is similarly inserted into the caudal screws approaching the apex of the kyphosis. KYPHOSIS CORRECTION CASE D EFORMITY It should be noted that some surgeons prefer to initially seat the rod into the proximal implants, performing sequential rod reduction into the distal screws. Figure 51 48

50 Kyphosis Correction Case At this point, several Rock-N-Roll Reducers and/or corkscrew devices may be used to sequentially reduce both rods into the rostral screw heads, working from the apex of the kyphosis towards the rostral aspect of the construct. Care should be taken to not excessively stress any single screw. To use the Rock-N-Roll Reducer, position the reducer so that the handles are 90 to the rod and grasp the screw head from above. The instrument is then rocked either medial or lateral as needed to capture the rod. The handles of the reducer can then be slowly compressed until the rod is fully seated into the implant (Figure 52). The Provisional T25 Driver is then used to advance and tighten the Set Screw. Using a cantilever bending moment, gradual reduction of the rods into the screw heads is performed with correction of the deformity. Typically sequential segmental compression is needed to complete correction of the spinal deformity. With this maneuver, the Set Screw on one side of the motion segment should be provisionally tightened, with the Set Screw loose in the implant to be compressed. The compression will occur against the provisionally tightened implant. If necessary, the Rod Gripper may also be utilized as a point of fixation against which to compress. Figure 52 KYPHOSIS CORRECTION CASE D EFORMITY Figure 52 For major deformity correction in severe kyphosis or fracture dislocations, both rods may be inserted in the caudal fixation points and the surgeon and assistant can each use a Rock-N-Roll Reducer on either side to gently pull the rostral screws up into the rod. Using two Rock-N-Roll Reducers simultaneously will further reduce stresses incurred at the bone/screw interface. 49

51 Kyphosis Correction Case When all implants are securely in place, final tightening of the Set Screw may be accomplished. An X10 CROSSLINK Plate may now be attached to the construct for increased torsional stability. The final construct should be verified by X-ray or fluoroscopy prior to closing to ensure that the desired sagittal plane correction is achieved (Figure 53). KYPHOSIS CORRECTION CASE D EFORMITY Figure 53 50

52 Degenerative L4 to S1 Fixation The following technique describes multi-level fixation of a degenerative case from L4 to S1 utilizing Multi Axial Screws. Once screw trajectories are determined, the pedicle screws are sequentially inserted into the vertebral body, using intraoperative posteroanterior and lateral plane radiographs or fluoroscopy to evaluate the position of the screws in two planes, either during or following the screw placement (Figures 54a and 54b). Figure 54a Figure 54b 51 L4 TO S1 FIXATION D EGENERAT IVE

53 Degenerative L4 to S1 Fixation When fully inserted, the screws should extend 50-80% into the vertebral body and be parallel to the superior endplate. For sacral fixation, especially when the bone is in poor condition, bicortical purchase may be utilized. Some surgeons also suggest targeting screws toward the tri-cortical point (the convergence of the S1 endplate to the anterior cortex), which provides the best fixation for the S1 pedicle screw. Once the screw is inserted, the Screwdriver sleeve should be disengaged from the screw and the instrument removed. Intraoperative EMG monitoring utilizing the NIM-SPINE System Neural Integrity Monitor may also be used if available (Figure 55). To verify proper placement of the screw use the NIM-SPINE System Stim-Controlled Ball Tip Probe or the Standard Ball Tip Probe to test the screw (Figure 56). L4 TO S1 FIXATION D EGENERAT IVE 52 Figure 55 Figure 56

54 Degenerative L4 to S1 Fixation If additional dorsal screw height adjustment is needed prior to rod placement, the Multi Axial Screw Height Adjuster may be utilized (Figure 57). The Set Screws may now be inserted into the Multi Axial Screw heads utilizing either the Dual Ended Set Screw Starter or the Dual Ended Set Screw Starter with Stops. The Dual Ended Set Screw Starter with Stops will ensure proper advancement of the Set Screw so it does not interfere with the rod channel (Figure 58). Figure 57 Figure 58 Seating the head of the Multi Axial Screw against the bone by advancing the screw will stiffen the multi axial component and facilitate Set Screw placement and rod seating. 53 L4 TO S1 FIXATION D EGENERAT IVE

55 Degenerative L4 to S1 Fixation Place the rod parallel to the side opening of the screws utilizing the Rod Inserter (Figure 59). The Set Screws can be advanced slightly using the Provisional T25 Driver to provisionally capture the rod into the head of the implants. L4 TO S1 FIXATION D EGENERAT IVE 54 Figure 59 A small lip on the head of the Multi Axial Screw is designed to accommodate provisional rod capture.

56 Degenerative L4 to S1 Fixation If the rod is not fully seated into the head of the implant, several reduction options are available to facilitate rod seating. The preferred reduction instrument is the single-hand operated Rock-N-Roll Reducer which enables effortless three-dimensional reduction of the rod to the screw. There are several Rock-N-Roll Reducer styles available to accommodate variations in screw placement and patient anatomy. To use the Rock-N-Roll Reducer, position the reducer so that the handles are 90 to the rod and grasp the screw head from above. The instrument is then rocked either medial or lateral as needed to capture the rod. The handles of the reducer can now be slowly compressed until the rod is fully seated into the implant (Figure 60). The T25 Provisional Driver is then used to advance and tighten the Set Screw. Figure 60 With multiple Rock-N-Roll Reducer styles available with the TSRH SILO Spinal System, the curved Rock-N-Roll Reducer provides two additionally unique advantages: the curved reduction arm assists in avoiding the lateral soft tissue, and a straight design at the tip of the instrument helps accommodate and facilitate sagittal adjustability. 55 L4 TO S1 FIXATION D EGENERAT IVE

57 Degenerative L4 to S1 Fixation When only a minimal amount of reduction is required, the Rocker Reducer can be used to reduce the rod into the head of the pedicle screw. Grasp the back of the screw head with the Rocker Reducer, ensuring that the rocker cam is positioned above the rod. The rocker is then pushed toward the rod, levering the rod into the screw head. The T25 Provisional Driver is then used to advance and tighten the Set Screw (Figure 61). L4 TO S1 FIXATION D EGENERAT IVE 56 Figure 61