Contact Fusion Cage. Surgical Technique

Transcription

1 Contact Fusion Cage Surgical Technique

2 Image intensifier control This description alone does not provide sufficient background for direct use of DePuy Synthes products. Instruction by a surgeon experienced in handling these products is highly recommended. Processing, Reprocessing, Care and Maintenance For general guidelines, function control and dismantling of multi-part instruments, as well as processing guidelines for implants, please contact your local sales representative or refer to: For general information about reprocessing, care and maintenance of Synthes reusable devices, instrument trays and cases, as well as processing of Synthes non-sterile implants, please consult the Important Information leaflet (SE_023827) or refer to:

3 Table of Contents Introduction AO Spine Principles 2 Indications/Contraindications 3 Implants 4 Surgical Technique 5 Implant Removal 15 Product Information Implants 18 Instruments 20 Bibliography 22 Contact Fusion Cage Surgical Technique DePuy Synthes 1

4 AO Spine Principles The four principles to be considered as the foundation for proper spine patient management underpin the design and delivery of the Curriculum: Stability Alignment Biology Function. 1,2 Stability Stabilization to achieve a specific therapeutic outcome axial sagittal coronal Alignment Balancing the spine in three dimensions Biology Etiology, pathogenesis, neural protection, and tissue healing Function Preservations and restoration of function to prevent disability Copyright 2012 by AOSpine 1 Aebi et al (1998) 2 Aebi et al (2007) 2 DePuy Synthes Contact Fusion Cage Surgical Technique

5 Indications/Contraindications Indications Lumbar and lumbosacral degenerative pathologies indicated for segmental spondylodesis including: Degenerative disc diseases and instabilities: Primary surgery for certain advanced disc disease or extensive decompression (laminectomy, facetectomy, foraminotomy) Revision surgery for failed disc operation, recurrence of disc herniation, postoperative instability Degenerative spondylolisthesis grade I or II Isthmic spondylolisthesis grade I or II Pseudarthrosis of failed spondylodesis Note: Additional posterior fixation with a pedicle screw system is recommended. Pre-operatively Female patient 60 years old, spondylolisthesis L4/L5 Post-operatively Spondylodesis with CONTACT Fusion Cages and additional fixation with pedicle screws (USS) Contraindications Severe osteoporosis Unstable burst fractures and compression fractures Destructive tumours Involvement of 3 or more levels Spondylolisthesis grade III and IV Acute infections Extensive peridural scarring Contact Fusion Cage Surgical Technique DePuy Synthes 3

6 Implants Intended Use The CONTACT Fusion Cage is an implant system for posterior lumbar interbody fusion (PLIF). It was designed to: Allow for interbody fusion in an optimum anatomical position Allow distraction of the disc space to be bridged and permit consequent restoration of disc height, lordosis and widening of the foramen Maintain the integrity of the endplates Allow for bone growth through the cage Design The CONTACT Fusion Cages have a rectangular cross section. They are introduced on the flat side and turned clockwise in order to spread the disc space and to bring the cage to the vertical position. When viewed from the side, the cages have a compact lenticular form that conforms to the sagittal section of the average lumbar disc (L4 L5, L5 S1). The posterior edges of the endplates are left intact which prevents the cage from posterior migration. The choice of seven implant sizes enables the desired disc height and natural lordosis to be restored. The cage is filled with milled bone graft. The graft is compressed firmly against the endplates by a compression insert which is screwed into the centre of the cage after implantation. The open inferior and superior surfaces are designed to allow for bone growth through the cage. The CONTACT Fusion Cages are manufactured of titanium alloy (TAN or TAV). 1 DePuy Synthes Contact Fusion Cage Surgical Technique

7 Surgical Technique 1. Position patient The PLIF procedures have to be performed in natural lordosis, either in the prone position or in a relaxed knee-chest position. Radiographic equipment is recommended for intraoperative control. 2. Approach and decompression of nerve roots Perform a midline incision. Do not strip the muscles farther laterally than the lateral aspect of the facet joints unless a posterolateral bone graft mass on the transverse processes is to be added. If necessary, carry out decompression at this stage of the operation. 3. Insert of pedicle screws Pedicle screws for additional posterior instrumentation can be inserted now or after having implanted the cages. The rods, however, are mounted on the screws only after insertion of the cages. Contact Fusion Cage Surgical Technique DePuy Synthes 5

8 Surgical Technique 4. Expose epidural space If maintained, the spinous and transverse processes and the attached ligaments provide additional stability. However, if resection is required, the bone can be used as bone graft material. In this case, the spinous and transverse processes of the vertebrae to be fused have to be carefully freed of all soft tissue and stored in a container under a moistened gauze. Perform a partial inferior laminotomy (1/3) of the upper adjacent vertebra. The medial half of the facet joints should always be removed. Use a gouge and perform a partial resection of the overlying inferior facet and lateral part of the laminar edge. At the L5 S1 level, you will find that the distal half of the lamina of L5 has to be removed in order to assure instrument access to the disc space. The underlying superior facet of S1 is then nibbled away to the level of the medial aspect of the pedicle. It is essential to make sufficient room laterally to avoid excessive retraction on the neural tissue, with great care being taken to protect the nerve root inside the fora men. 1 DePuy Synthes Contact Fusion Cage Surgical Technique

9 5. Prepare disc space Open the posterior anulus (Anulus fibrosus) and carefully remove the nucleus (Nucleus pulposus). To prevent an accidental perforation of the anterior anulus, use a curette neither too small nor too sharp ( ). It is essential that the endplate be scraped free of all cartilage, however the bone should not be perforated. Great care should be taken to protect the nerve root and the dura. (It will be easier to complete the cleaning of the endplates later, when the disc space has been opened with spreaders [ ].) Note: Adequate cleaning of the endplates is important for vascular supply of the bone graft. Excessive cleaning, however, may weaken the endplates due to removal of bone underlying the cartilaginous layers. Removing the entire endplate may result in subsidence and loss of segmental stability. Contact Fusion Cage Surgical Technique DePuy Synthes 1

10 Surgical Technique 6. Open disc space Introduce a small Disc Space Opener (4/8 mm or 5/9 mm ) into the opposite side of the intervertebral space (1). Separate the posterior edges of the vertebral bodies, which may be in very close contact, by turning the instrument 90 clockwise (2) Spread disc space Protect the nerve root and dura with a root retractor. Introduce the smallest Vertebral Body Spreader (7/9 mm ) on your side until the laser marks behind the head of the spreader are flush with the posterior edge of the vertebral body (1), and turn it 90 clockwise in order to spread the disc space (2). 2 1 If the vertebral body spreader is not seated firmly between the vertebral bodies, replace it with the next bigger Vertebral Body Spreader (8/10 mm ), inserting it in the same way. Repeat spreading the disc space by introducing the next bigger spreader until you feel by resistance of the tended anulus that the disc space has been enlarged to its natural height. This last spreader should remain in place until the first cage is introduced on the other side. Warning: Take care not to over-distract. 8 DePuy Synthes Contact Fusion Cage Surgical Technique

11 8. Select appropriate cage size Choose a CONTACT Fusion Cage ( ) of the same height as the largest accepted vertebral body spreader. 9. Pick up cage Position the CONTACT Fusion Cage Holder ( ) on the cage (1). Turn the knob as far as it will go thus screwing the implant holder onto the cage (2). Pick up the second cage in the same manner. 2 1 Contact Fusion Cage Surgical Technique DePuy Synthes 1

12 Surgical Technique 10. Fill cages with bone graft Pack the cages with finely milled autologous bone (the resected bone from the spinous processes and the facet joints will generally be sufficient). Use the Bone Com pres sion Forceps ( ) to compress the bone within the cages. 11. Fill anterior disc space To create desired conditions for the fusion, fill the anterior disc space with cancellous bone graft before intro ducing the cages. 11 DePuy Synthes Contact Fusion Cage Surgical Technique

13 12. Introduce cage Introduce the flat side of the cage into the disc space with gentle hammer blows. The handle should always point away from the midline at introduction (in order to avoid interfering with the handle on the other side when the cage is turned). The nerve roots and dura must be protected by a retractor. Introduce the cage to the appropriate depth, 3 to 4 mm beyond the posterior edge of the vertebral body. When the shoulder of the implant holder tip is flush with the posterior edge of the vertebral body, the cage is advanced enough. Although the anterior anulus is resistant in most patients, be aware that the resistance of the anterior anulus can be lost in a very degenerated disc. If in doubt, check desired positioning of the cages with a lateral X-ray. Note: Although the anterior annulus fibrosus and the anterior longitudinal ligament are resistant in most patients, this resistance may be lacking in the case of degenerated discs. Be aware of the risk of perforation. 13. Turn cage to upright position Turn the cage clockwise. When the handle of the implant holder is parallel to the body axis, the cage is positioned vertically. Note: Should it be necessary to turn the cage back on its side again, this must be done in a counter-clockwise direction. 90 Contact Fusion Cage Surgical Technique DePuy Synthes 11

14 Surgical Technique 14. Loosen knob slightly Loosen the knob by slightly turning it. 15. Retract sleeve and screw in compression insert Holding it by its flange, retract the sleeve as far as it will go (1). This releases the internal locking mechanism of the com pression insert. In this position, the compression insert can be screwed in thus compressing the bone graft (2) DePuy Synthes Contact Fusion Cage Surgical Technique

15 16. Remove implant holder Unscrew the compression insert (1) and disengage the implant holder from the cage (2). 1 Option If there is ample space on both sides of the dura, the handle may be left connected to the first cage during the insertion of the second cage Introduce second cage Repeat the steps 9 to 16 on the other side. Ensure that the second cage does not displace the first when introduced. It should be introduced clear from the first, and inserted as lateral as possible. Fill in the space between the cages with cancellous bone, too, to achieve, as far as possible, a solid fusion. Contact Fusion Cage Surgical Technique DePuy Synthes 13

16 Surgical Technique 18. Posterior stabilisation Additional internal fixation with a pedicle screw fixation system is recommended. Perform an additional posterolateral fusion if necessary. Close the wound over a suction drain. 11 DePuy Synthes Contact Fusion Cage Surgical Technique

17 Implant Removal 1. Insert shaft into cage If necessary, the cage can be removed using the Emergency Holder ( ). Screw the inner shaft of the Emergency Holder into the thread of the cage. 2. Slide sleeve on shaft Mount the Sleeve of the emergency holder on the shaft and ensure that the coupling part of the sleeve fits into the slot of the cage. Contact Fusion Cage Surgical Technique DePuy Synthes 15

18 Implant Removal 3. Mount L-handle Mount the L-Handle ( ) onto the sleeve of the emergency holder by pressing the coupling forward. 4. Mount knob Mount the Knob provided as part of the Emergency Holder ( ) onto the threaded shaft and firmly tighten it. 11 DePuy Synthes Contact Fusion Cage Surgical Technique

19 5. Remove cage Turn the cage counter-clockwise (1) and remove it carefully (2) with gentle taps of the Slotted Hammer ( ). 2 1 Contact Fusion Cage Surgical Technique DePuy Synthes 11

20 Implants Contact Fusion Cage, Titanium Alloy (TAN) Non-sterile CONTACT Fusion Cage, width 8 mm, height 9 mm CONTACT Fusion Cage, width 8 mm, height 10 mm CONTACT Fusion Cage, width 9 mm, height 11 mm CONTACT Fusion Cage, width 9 mm, height 12 mm CONTACT Fusion Cage, width 10 mm, height 13 mm CONTACT Fusion Cage, width 11 mm, height 14 mm CONTACT Fusion Cage, width 11 mm, height 15 mm Sterile S CONTACT Fusion Cage, width 8 mm, 9 mm S CONTACT Fusion Cage, width 8 mm, 10 mm S CONTACT Fusion Cage, width 9 mm, 11 mm S CONTACT Fusion Cage, width 9 mm, 12 mm S CONTACT Fusion Cage, width 10 mm, 13 mm S CONTACT Fusion Cage, width 11 mm, 14 mm S CONTACT Fusion Cage, width 11 mm, 15 mm 11 DePuy Synthes Contact Fusion Cage Surgical Technique

21 Contact Fusion Cage, Titanium Alloy (TAV) Non-sterile V CONTACT Fusion Cage, width 8 mm, height 9 mm V CONTACT Fusion Cage, width 8 mm, height 10 mm V CONTACT Fusion Cage, width 9 mm, height 11 mm V CONTACT Fusion Cage, width 9 mm, height 12 mm V CONTACT Fusion Cage, width 10 mm, height 13 mm V CONTACT Fusion Cage, width 11 mm, height 14 mm V CONTACT Fusion Cage, width 11 mm, height 15 mm Sterile VS VS VS VS VS VS VS CONTACT Fusion Cage, width 8 mm, 9 mm CONTACT Fusion Cage, width 8 mm, 10 mm CONTACT Fusion Cage, width 9 mm, 11 mm CONTACT Fusion Cage, width 9 mm, 12 mm CONTACT Fusion Cage, width 10 mm, 13 mm CONTACT Fusion Cage, width 11 mm, 14 mm CONTACT Fusion Cage, width 11 mm, 15 mm Contact Fusion Cage Surgical Technique DePuy Synthes 11

22 Instruments Slotted Hammer, 9.5 mm Bone Compression Forceps, for CONTACT Fusion Cage Disc Space Opener, width 4 mm, height 8 mm Disc Space Opener, width 5 mm, height 9 mm Vertebral Body Spreader, width 7 mm, height 9 mm Vertebral Body Spreader, width 8 mm, height 10 mm Vertebral Body Spreader, width 8 mm, height 11 mm Vertebral Body Spreader, width 8 mm, height 12 mm Vertebral Body Spreader, width 8 mm, height 13 mm Vertebral Body Spreader, width 8 mm, height 14 mm Vertebral Body Spreader, width 8 mm, height 15 mm L-Handle with Quick Coupling, for CONTACT Fusion Cage 21 DePuy Synthes Contact Fusion Cage Surgical Technique

23 CONTACT Fusion Cage Emergency Holder Bone Curette, rectangular, 6 9 mm, length 250 mm CONTACT Fusion Cage Holder, with Compression Insert Contact Fusion Cage Surgical Technique DePuy Synthes 21

24 Bibliography Aebi M, Arlet V, Webb JK, (2007): AOSPINE Manual (2 vols), Stuttgart, New York: Thieme. Aebi M, Thalgott JS, Webb JK (1998): AO ASIF Principles in Spine Surgery. Berlin: Springer. 22 DePuy Synthes Contact Fusion Cage Surgical Technique

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28 Synthes GmbH Eimattstrasse Oberdorf Switzerland Tel: Fax: Not all products are currently available in all markets. This publication is not intended for distribution in the USA. All surgical techniques are available as PDF files at DePuy Synthes Spine, a division of Synthes GmbH All rights reserved DSEM/SPN/0316/0460(1) 08/17