Xia Anterior System Anterior System of the Xia Family. Surgical Technique

Transcription

1 System Anterior System of the Xia Family Surgical Technique

2 Introduction Introduction Stryker Spine is proud to introduce the Xia Anterior Spinal System. This System provides surgeons with a simple solution to anterior thoracolumbar trauma, tumor and scoliosis correction. Xia Anterior is based upon the same philosophies that make the Xia System one of the best thoracolumbar systems in the world today: Comprehensive Anatomical Implants Surgeon friendly instruments Buttress Thread Closure Mechanism Important - The Xia implants and instruments are designed and tested for use only with the Xia Spinal System. This Surgical Technique sets forth detailed, recommended procedures for using the Xia Spinal System implants and instruments. It offers guidance that you should heed but, as with any such technical guide, each surgeon must consider the particular needs of each patient and make appropriate adjustments when necessary and as required. Note: This is intended as a guide only. There are multiple techniques for the insertion of pedicle screws and, as with any surgical procedure, a surgeon should be thoroughly trained before proceeding. 2

3 Table of Contents Operative Technique A. Patient Positioning B. Staple Placement C. Screw Insertion D. Vertebral Body Distraction E. Rod Placement and Compression F. Final Tightening G. Crosslinks Patient Positioning Screw Insertion Implant Overview Instrument Overview Implant&Instrument Overview Vertebral Body Distraction Final Tightening Rod Placement and Compression 3

4 A. Patient Positioning Anterior thoracolumbar instrumentation procedures are generally performed in the straight lateral position with the assistance of a general, thoracic, or vascular surgeon. Consult with the access surgeon to decide the optimal side of approach. An approach from the side of worst pathology is recommended in this Operative Technique. Though in general (below the thoracolumbar junction), the spine is often approached from the left to avoid the liver. Higher in the thoracic spine, a right-sided approach is recommended. For approaches in the lumbar spine, flex the ipsilateral lower extremity to decrease lumbar-sacral plexus and psoas tension. Typically, vascular surgery will flex the contralateral lower extremity. Fig. 1 4

5 A. Patient Positioning Patient Positioning Maintain the position of the patient with bean bags and balsters. Larger patients will benefit from kidney rests or other devices that fix to the operating table. Carefully pad all bony prominences and maintain appropriate cervical spine alignment. Patient Positioning Fig. 2 Improve surgical access by increasing the distance between the shoulder girdle and the pelvic rim. For flat spinal frames, center a gel roll at the intended surgical level. For flexible or standard operative tables, gatch the table at the intended surgical level. Be careful about these maneuvers as iatrogenic scoliosis is possible in patients with burst fractures or other unstable lesions. Always unlatch the table or remove the gel roll prior to final implant tightening. Confirm level localization. The involved level is often obvious with tumors and fractures, but a radiograph helps to orient the surgeon to regional anatomy. Combine a rib count with the radiograph to confirm the level of the thoracic spine. 5

6 B. Staple Placement Staple Placement Staple Preparation and Insertion Implantation begins with the placement of the Dual Hole Staple. These staples come in small, medium, and large sizes and help distribute cantilever loads across the entire vertebral body. The largest Dual Hole Staple for the vertebral body should be used to ensure the greatest surface-to-surface contact. Rostral staples are green and Caudal staples are gray. Clamp the staple with the Xia Dual Hole Staple Holder/Impactor ( ), then tighten by turning the clamp until finger tight. Ensure that the tetra spikes on the staple are facing towards the vertebral body when implanting. Fig. 4 Fix the staple onto the vertebral body with a mallet. The Dual Hole Staples are marked anterior and posterior for left-sided approaches so be careful with right-sided approaches as these markings will be reversed. This system is designed so that when the construct is complete, the anterior rod is longer. In some cases, it may be convenient for the longer rod to be placed posterior. In either case, avoid a parallelogram configuration with same sized-rods as this may be weaker than trapezoidal constructs. Fig. 5 6

7 C. Screw Insertion Screw Preparation and Insertion Fig. 6 Once the staples are placed, proceed with screw insertion. The entry point can be further prepared with the Xia Angled Awl ( ) or Xia Straight Awl ( ). Note: There is a tendency for surgeons to place the staple too far anteriorly on the vertebral body. To avoid this, surgeons should generously resect the rib head and adequately retract the solis muscle. The surgeon should then be able to pass a probe along the posterior cortex and use this as a guide for staple placement. Screw Insertion The pathway is then completed with the Probe-Finder ( ). Advance the Probe-Finder slowly and palpate the contralateral cortex before penetration. The surgeon should feel the Probe- Finder piercing the opposite cortex. To ensure bicortical passage of the vertebral body, measure the depth of the vertebral body with the Depth Guage (884025). Fig. 7 For the posterior screw tracts use either Awl to create a pathway angled 10 degrees anteriorly to avoid the spinal canal. For the anterior screw tracts use either Awl to create a pathway perpendicular to the vertebral body. Fig. 8 7

8 C. Screw Insertion Screw Insertion The Monoaxial Screwdriver ( ) provides rigid connection between the monoaxial screws and the screwdriver. After the vertebral body pathway is prepared, proper screw length and diameter determined, the screw is inserted. The Xia Anterior System is limited to use with 5.5, 6.5 and 7.5mm diameter monoaxial screws. Fig. 9 Three monoaxial screw diameters (5.5, 6.5, and 7.5mm) are available in lengths ranging from 30 to 60mm except the 5.5mm diameter screws which are available from 30 to 50mm. The 6.5mm screw is used in the majority of cases. For patients with large vertebral bodies or significant osteoporosis, surgeons should consider using 7.5mm diameter screws. Avoid placing 7.5mm diameter screws in at angles greater then 10 degrees to prevent the screw from binding in the dual hole staple. Fig. 10 8

9 D. Vertebral Body Distraction Distraction Once all screws are in place, distract the corpectomy defect using the Parallel Distractor ( ). Place the feet of the Parallel Distractor into the heads of the most anterior Xia screws to aid in graft placement. Insert the Closure Screw into the Xia Screw using the 5mm Tightener. Provisionally tighten the Closure Screws to ensure that the Parallel Distractor and Xia Screws remain rigid during distraction. Fig. 11 Distract the vertebral space by expanding the arms of the Parallel Distractor by rotating the key clockwise. Measure and place the bone graft into the corpectomy site. Release the distractor by depressing the key. Vertebral Body Distraction Fig. 12 9

10 E. Rod Placement and Compression Rod Contouring Once all screws are inserted, use the appropriate pre-cut rods or cut a longer rod with the Cutting Pliers ( ). The Rod Template ( ) is used to accurately determine the appropriate rod length and curvature. Fig. 13 Note: Bending is seldom necessary but if needed can be performed with the French Benders ( ). The Rod Insertion Forceps ( ) are used to place the rod onto the construct. Next use the Universal Tightener ( ) to place the closure mechanism into the screw heads. Rod Placement and Compression Fig. 15 Fig. 14 Note: The Closure Screw is laser etched to clearly differentiate it from the Stainless Steel Closure Screw. It is important not to mix and implants. 10

11 E. Rod Placement and Compression The Xia System offers three options for linking the rod to the spine: Inserter and Universal Tightener Option 1: The Inserter ( ) can help align the Universal Tightener ( ) and the Closure Screw with the implant. The two engraved lines on the Universal Tightener denote the following: When the lower line is aligned with the top of the Inserter, the Closure Screw is at the top of the implant. Fig. 16 When the upper line is aligned with the top of the Inserter, the Closure Screw is fully introduced into the implant. Note: Do not perform final tightening of the Closure Screw with the Inserter in place, or it will not be possible to remove the Inserter. Fig. 17 Option 2: Rod Fork and Universal Tightener The Rod Fork ( ) is used when the rod is slightly proud with respect to the seat of the implant. The Rod fork easily slides into the lateral grooves on the implant head and is rotated backwards. This levers the rod into the head of the implant. The Closure Screw is inserted with the Universal Tightener when the rod is fully seated into the head of the implant. Rod Placement and Compression Option 3: Persuader and Universal Tightener If necessary use the Persuader ( ) to seat the rod into the screw head. Fig

12 E. Rod Placement and Compression In the event the rod is forced down while tightening the Closure Screw, be sure that the Closure Screw is fully engaged into the screw head. This will help resist the high reactive forces generated by the final tightening maneuvers. Extra caution is advised when: 1) The rod is not horizontally placed into the screw head 2) The rod is high in the screw head 3) An acute convex or concave bend is contoured into the rod. Fig. 19 Compress the corpectomy defect to lock the bone graft or intervertebral body device using the Parallel Compressor ( ). Rod Placement and Compression Fig

13 F. Final Tightening Using Torque Wrench Once the correction procedures have been carried out and the spine is fixed in a satisfactory position, the final tightening of the Closure Screw is done by utilising the Anti-Torque Key and the Torque Wrench. The Torque Wrench indicates the optimum force which has to be applied to the implant for final tightening. Line up the two arrows to achieve this optimum torque of 12Nm. Note: It is recommended that 12Nm is not exceeded during final tightening. Fig. 22 Note: The Anti-Torque Key must be used for final tightening. The Anti- Torque performs two important functions: 1) It allows the Torque Wrench to align with the axis of the tightening axis. 2) It provides the equal and opposite torque that would otherwise be transmitted to the rest of the construct. Final Tightening Note: If the Anti-Torque Key cannot be easily removed from the implant head, the rod may not be fully seated. Fig

14 G. Crosslinks Crosslinks improve the construct s torsional rigidity. Use the Crosslink Caliper ( ) to measure proper rod-to-rod distance. Crosslinks are available from 15 to 20mm in 1mm increments. Fig. 23 Place the crosslink onto the rod using the Crosslink Holder ( ). Tighten the crosslink set screws with the 3.5mm Anterior Hex Driver ( ), sequentially moving from one set screw to the other until the device is firmly seated. Fig. 24 Crosslinks 14

15 Xia Implants Xia Instruments Optional Instruments Ref # Description Ref # Description Closure Mechanism Monoaxial Screwdriver Ø 5.5mm Monoaxial Screws 30-50mm Ø 6.5mm Monoaxial Screws 30-60mm Ø 7.5mm Monoaxial Screws 30-60mm Ø 6.0mm Alloy Rod mm N/A Ø 6.0mm CP Rod N/A Shaft for Monoaxial Screwdriver Angled Awl Parallel Compressor Dual Staple Holder/Impactor Ø 5.5mm Standard Rod N/A Single Staple Impactor Ø 5.5mm Stiff Rod N/A Washer Single Hole Staple Stainless Cross Connector 15-20mm Dual Hole Staples (Sm, Med, Lg) (Caudal/Rostral) mm Anterior Hex Driver Parallel Distractor Cross Connector Caliper Cross Connector Holder Depth Gauge (Centaur) Persuader Implant&Instrument Overview Anterior Instrument Tray 15

16 Simple Way to Strong Support Spinal Systems of the Xia Family: Modern Solutions for All Your Applications Stryker SA Cité Centre Grand-Rue Montreux Switzerland t: f: This document is intended solely for the use of healthcare professionals. A surgeon must always rely on his or her own professional clinical judgment when deciding whether to use a particular product when treating a particular patient. Stryker does not dispense medical advice and recommends that surgeons be trained in the use of any particular product before using it in surgery. The information presented is intended to demonstrate the breadth of Stryker product offerings. A surgeon must always refer to the package insert, product label and/or instructions for use before using any Stryker product. Products may not be available in all markets because product availability is subject to the regulatory and/or medical practices in individual markets. Please contact your Stryker representative if you have questions about the availability of Stryker products in your area. Stryker Corporation or its divisions or other corporate affiliated entities own, use or have applied for the following trademarks or service marks: Stryker, XIA. All other trademarks are trademarks of their respective owners or holders. The products listed above are CE marked according to the Medical Device Directive 93/42/EEC. Literature Number: MTXLXAST MTX6774/GS 06/10 Copyright 2010 Stryker