AXON - synthes.vo.llnwd.netsynthes.vo.llnwd.net/o16/LLNWMB8/INT Mobile/Synthes... · 7.3 Connecting Rods, Pure Titanium (TiCP) • Available in lengths 300 mm and 500 mm Art. No

SURGICAL TECHNIQUE

Top-loading Implant System for the Posterior Stabilisation of the Cervical and Upper Thoracic Spine

AXON

Instruments and implants approved by the AO Foundation.This publication is not intended for distribution in the USA.

Top-loading Implant System for the Posterior Stabilisation of the Cervical and Upper Thoracic SpineCervical and Upper Thoracic Spine

This publication is not intended for distribution in the USA.

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WarningThis 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 MaintenanceFor 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:http://emea.depuysynthes.com/hcp/reprocessing-care-maintenanceFor 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: http://emea.depuysynthes.com/hcp/reprocessing-care-maintenance

Axon Surgical Technique DePuy Synthes 1

INTRODUCTION Axon 2

AO ASIF Principles 3

Indications and Contraindications 4

IMPLANTS AND INSTRUMENTS Implants 5

Instruments 9

Axon Vario Cases 14

SURGICAL TECHNIQUE Surgical Technique 15

Additional Techniques 24

Remobilising Variable Axis Heads 27

TABLE OF CONTENTS

30° 30°

1 DePuy Synthes Axon Surgical Technique

AXON. TOP-LOADING IMPLANT SYSTEM FOR THE POSTERIOR STABILISATION OF THE CERVICAL AND UPPER THORACIC SPINE.

Flexible implant systemThe Axon implants can be adjusted to suit the individual patient anatomy.

Cancellous bone and cortex screws

Locking screw for angularly stable locking and fi xation of the rod

Simple top-loading rod insertion

30° of angulation in all directions permits screw inser-tion according to the Magerl technique

Self-tapping screws for rapid insertion


AO ASIF principles of internal fixation

In 1958, the AO ASIF (Association for the Study of Inter-nal Fixation) established four basic principles1 which have become the guidelines for internal fi xation.

These principles are: • Anatomic reduction• Stable internal fi xation• Maintenance of blood supply• Early active, pain-free mobilization

The fundamental aims of fracture treatment in the limbs and fusion of the spine are the same. A specifi c goal in the spine is returning as much function as possible to the injured neural elements.2

AO ASIF principles as applied to the spine3

Anatomic reductionRestoration of normal spinal alignment to improve the bio mechanics of the spine

Stable internal fixationStabilisation of the spinal segment to promote bony fusion.

Maintenance of blood supplyCreation of an optimal environment for fusion

Early, pain-free mobilizationMinimisation of damage to the spinal vasculature, dura, and neural elements can reduce pain and can contribute to improved function for the patient.

AO ASIF PRINCIPLES

1 Müller ME, Allgöwer M, Schneider R, Willenegger R (1991) AO Manual of Internal Fixation. 3rd ed. Berlin: Springer

2 Ibid.3 Aebi M, Thalgott JS, Webb JK (1998) AO ASIF Principles in Spine Surgery.

Berlin: Springer


The Axon System is a comprehensive set of instruments and implants, including • top-loading variable axis screws, • hooks,• transverse bars and• rods.

It is designed for posterior stabilisation of the cervical spine and upper thoracic spine. The implants provide the flexibility required to accommodate variations in patient anatomy.

The Axon System uses the existing CerviFix rods, allow-ing components from Axon and CerviFix to be com-bined. This allows a construct to extend from the occiput to the lower spine using the Universal Spine System (USS).

IndicationsInstabilities in the upper cervical spine and in the occipi-tocervical region: • Rheumatoid arthritis • Congenital anomalies• Posttraumatic conditions• Tumours• Infections

Instabilities in the lower cervical and upper thoracic spine: • Posttraumatic conditions• Tumours• Iatrogenic instabilities following laminectomy etc.

Degenerative and painful posttraumatic conditions in the lower cervical and upper thoracic spine

Anterior cervical fusions requiring additional posterior stabilisation

Contraindications• Spinal destruction accompanied by a loss of ventral

support (caused by tumours, fractures and infections) results in major instability of the cervical spine and up-per thoracic spine. In this situation, stabilisation with Axon is not sufficient. Additional anterior stabilisation is crucial.

• Severe osteoporosis

INDICATIONS AND CONTRAINDICATIONS


1. Axon Variable Axis Screws

1.1 Cancellous Bone Screws, Titanium Alloy (TAN)• Feature up to 30° of angulation in all directions • Available as cancellous self-tapping screws with

B3.5 or 4.0 mm, colour coded• Screws offer from 8 mm to 50 mm bone purchase

1.1.1 Cancellous Bone ScrewsB3.5 mm

IMPLANTS

Art. No. Length

405.508 8 mm

405.510 10 mm

405.512 12 mm

405.514 14 mm

405.516 16 mm

405.518 18 mm

405.520 20 mm

405.522 22 mm

405.524 24 mm

405.526 26 mm

Art. No. Length

04.200.614 28 mm

04.200.615 30 mm

04.200.616 32 mm

04.200.617 34 mm

04.200.618 36 mm

04.200.619 38 mm

04.200.620 40 mm

04.200.621 42 mm

04.200.622 44 mm

04.200.623 46 mm

04.200.624 48 mm

04.200.625 50 mm

1.1.2 Cancellous Bone ScrewsB4.0 mm

Art. No. Length

405.458 8 mm

405.460 10 mm

405.462 12 mm

405.464 14 mm

405.466 16 mm

405.468 18 mm

405.470 20 mm

405.472 22 mm

405.474 24 mm

405.476 26 mm

Art. No. Length

04.200.664 28 mm

04.200.665 30 mm

04.200.666 32 mm

04.200.667 34 mm

04.200.668 36 mm

04.200.669 38 mm

04.200.670 40 mm

04.200.671 42 mm

04.200.672 44 mm

04.200.673 46 mm

04.200.674 48 mm

04.200.675 50 mm


1.3 Axon Shaft Screws, Titanium Alloy (TAN)• Feature up to 15° of angulation in all directions • Available as cortex self-tapping screws withB3.5 mm• Screws offer from 22 mm to 36 mm bone purchase

with a 10 mm smooth, thread-free section

2. Screws to Secure Occiput, Titanium Alloy (TAN)• Available as cortex self-tapping screws withB3.5 mm• With ball head• Screws from 10 mm to 16 mm in length

1.4 Axon Locking Screw, Titanium Alloy (TAN)• For angular-stable locking and fixation of the rod

Art. No.

406.104 Locking screw

Art. No. Length

405.486 22 mm

405.487 24 mm

405.488 26 mm

405.489 28 mm

Art. No. Length

404.310 10 mm

404.312 12 mm

Art. No. Length

405.490 30 mm

405.491 32 mm

405.492 34 mm

405.493 36 mm

Art. No. Length

404.314 14 mm

404.316 16 mm

1.2 Cortex Screws,B3.5 mm Titanium Alloy (TAN)• Feature up to 30° of angulation in all directions • Available as cortex self-tapping screws withB3.5 mm• Screws offer from 28 mm to 50 mm bone purchase

Art. No. Length

404.528 28 mm

404.530 30 mm

404.532 32 mm

404.534 34 mm

404.536 36 mm

404.538 38 mm

Art. No. Length

404.540 40 mm

404.542 42 mm

404.544 44 mm

404.546 46 mm

404.548 48 mm

404.550 50 mm

Implants


4. Axon Transverse Bar, open, Titanium Alloy (TAN)• Provides a lateral offset of up to 9 mm from the

3.5 mm rod to the screw• Eliminates the need for severe rod contouring• Can be placed onto the rod from the top after the

Axon construct is in position

Art. No.

406.105 Transverse Bar

5. Axon Laminar Clamps, gold, Titanium Alloy (TAN)• For adding a laminar substitute in conjunction with a

3.5 mm rod (cf. 7.) (cross link)

Art. No.

498.950 CerviFix Laminar Clamp, right

498.951 CerviFix Laminar Clamp, left

6. Transverse Connector, Titanium Alloy (TAN)• Premounted• Easily placed after the Axon construct is in place• Swivel ring allows the clamps to be placed in different

directions• Plate can be locked rigid

Art. No. Length

498.916 60 mm

498.917 75 mm

3. Axon Hooks, Titanium Alloy (TAN)• For sublaminar insertion and stabilisation• Different offsets ease construct assembly• Easily placed and exchanged after Axon construct

is in place

Art. No.

499.406 Right, small

499.407 Left, small

499.408 Right, large

499.409 Left, large


7.2 Occiput RodB3.5 mm, Pure Titanium (TiCP) • Length 240 mm

Art. No.

498.956 CerviFix Occiput Rod

7.3 Connecting Rods, Pure Titanium (TiCP)• Available in lengths 300 mm and 500 mm

Art. No. Length B

498.936 300 mm 3,5/5,0 mm

498.937 300 mm 3,5/6,0 mm

498.938 500 mm 3,5/6,0 mm

498.939 500 mm 3,5/5,0 mm

8. Parallel Connector, Titanium Alloy (TAN)

Art. No.

498.935 CerviFix Parallel Connector,

B3.5/3.5 mm

498.959 Parallel Connector for USS Paediatric

Rods,B3.5/5.0 mm, light blue

498.960 CerviFix Parallel Connector,

B3.5/6.0 mm

7. Rods

7.1 RodsB3.5 mm, Titanium Alloy TAN or Pure Titanium TiCP• Available in lengths 80 mm, 120 mm and 240 mm

Art. No. Length Material

498.120 80 mm TAN

498.925 80 mm TiCP

498.125 120 mm TAN

498.926 120 mm TiCP

498.957 240 mm TiCP

Implants


INSTRUMENTS

Screw site preparation instrument

388.397 AwlB3.5 mm

388.396 Handle with Quick Coupling, small

388.394 Drill BitB2.4 mm with Stop, for Quick Coupling

292.745 Kirschner WireB2.4 mm, with Stop

388.393 Drill Sleeve with Scale, for Drill BitB2.4 mm

• Drilling depths can be set from 6 mm to 50 mm (in 2-mm increments).

• Teeth at the tip of the drill sleeve reduce risk of slippage during drilling process.

388.070 Guide Sleeve for Tap

311.349 Tap for Cancellous Bone Screw

B3.5 mm, for Quick Coupling

389.477 Tap for Cortex ScrewB3.5 mm, for Quick Coupling

389.472 Pedicle ProbeB2.0 mm

388.549 Feeler, straight with rounded tip


319.009 Depth Gauge for ScrewsB3.5 to 4.0 mm, measuring range up to 50 mm

• Provides direct measurement for screw selection.

389.476 Reamer for Axon Screws

• Removes excess bone around the screw site to enable rotation of Axon Variable Axis Screw Head.

Instruments for inserting screws

388.395 Screwdriver, hexagonal, long,B2.5 mm, length 293 mm

388.391 Holding Sleeve, for no. 388.395388.398 Screwdriver, hexagonal with preassem-

bled Holding Sleeve,B2.5 mm388.399 Outer sleeve for screwdriver 388.398

Rod Instruments

388.868 Trial rod,B3.5 mm388.869 Occiput Trial rod,B3.5 mm

388.407 Holding forceps for RodsB3.5 mm

• Forceps provide a secure insertion of the rod into the operative site.

• The instrument can be used to insert and manipulate the hooks.

Instruments

389.473 Pedicle Marker, small, with short markings389.474 Pedicle Marker, small, with long markings

• Used to radiographically confirm position.

• Markings indicate depth in 10-mm increments.

• Two types of marking can be used to distinguish left and right pedicles.


388.011 CerviFix Holding forceps for RodsB3.5 mm

391.990 Cutting Pliers for Plates and Rods

389.478 Bending Pliers for RodsB3.5 mm

• Allows 3D contouring. • Dial setting determines bend radius of

rod.

388.924 Bending Iron, right, forB3.5 mm rods 388.925 Bending Iron, left, forB3.5 mm rods

Construct assembly instruments

389.479 Alignment Tool

• Used for adjusting the orientation of the screw head prior to rod place-ment.

388.392 Screwdriver Shaft Stardrive 3.5, T15, self-holding, for Quick Coupling

• Used with 2 Nm Torque Limiting Handle.

• To pick up the locking screws and to screw fit the construct with an appro-priate torque.


388.038 Crimper for Transverse Connector

• Locks the swivel ring connection of the transverse connector.

Instruments

388.408 Compression Forceps

388.405 Distraction Forceps

388.504 Rod Insertion Instrument

• The “Persuader” can be used to intro-duce the screw onto the rod and to fa-cilitate the introduction of the locking screw through the sleeve.

• Also provides countertorque for final tightening of the construct.

389.471 Handle with Torque Limiter, 2.0 Nm, with Quick Coupling

388.349 Rod Pusher

• To place the rod in the Axon screw head and to facilitate locking screw introduction. Also provides counter-torque for final tightening of the construct.


Screw remoblization instruments

388.548 Instrument for Remobilizing of Axon Screws

Occiput fixation instruments


• For depth measurement through the plate

312.860 Handles for Drill Guide Inserts, for nos. 312.880 and 388.017

312.880 Handle for Drill Guide Inserts, 3.5, with Knurled Nut, for no. 312,860

388.017 Drill Guide Insert 2.7 calibrated, with Knurled Nut, for no. 312.860

388.020 Screwdriver, hexagonal, small, self-holding

311.440 T-Handle with Quick Coupling

315.630 Drill BitB2.5 mm, 3 flute, for Quick Coupling

311.330 Tap for Cortex ScrewsB3.5 mm


687.098 Vario Case for Axon Instruments

AXON VARIO CASES

687.099 Vario Case for Axon Implants

Module in 687.099

687.093 Module, size ½, for Axon Screws 687.027 Module, size ¼, for additional Axon Implants

Optional Module for Vario Case 687.099

687.120 Module, size ¼, for additional Axon Screws

687.121 Module, size ¼, for Occiput Fixation


SURGICAL TECHNIQUE

The following surgical technique is described using the example of a C3–C5 screw insertion. For occiput fixation please refer to the CerviFix Surgical Technique.

1AccessUsing the standard surgical approach, expose the spinous processes and laminae of the vertebrae to be fused.

2Predrill screw hole

Required instruments

388.397 AwlB3.5 mm

Determine the entry point and the trajectory for the screw.1

Create a pilot hole with the awl. This helps prevent displacement of the drill bit during initial insertion.

1 For correct screw placement see detailed information in: – CerviFix Surgical Technique (Art. No. 036.000.261) – Aebi M, Thalgott JS, Webb JK (1998) AO ASIF Principles in Spine Surgery.

Berlin: Springer


Surgical Technique

3Set drill sleeve depth


388.393 Drill Sleeve with Scale, for Drill BitB2.4 mm (388.394)

Slide back the latch of the drill sleeve to release the inner tube.

Adjust the position of the inner tube in the window so that the mark on the inner tube indicates the required depth.

Release the latch to lock the drill sleeve at the desired depth.


4Drill hole


388.394 Drill BitB2.4 mm with Stop, 2 flute, for Quick Coupling

388.393 Drill Sleeve with Scale, for Drill BitB2.4 mm (388.394)


Drill to desired trajectory and depth using the drill bit and the drill sleeve.

Option

Optional instruments

292.745 Kirschner WireB2.4 mm, with Stop

389.472 Pedicle ProbeB2.0 mm

388.549 Feeler, straight with rounded tip

389.473/474 Pedicle Marker, small, with short/long markings

Alternative: Determine the trajectory and depth using the Kirschner Wire and the Drill Sleeve.

The bone can then be prepared with the small Pedicle Probe. To confirm accurate screw placement within the bone, use the straight feeler to palpate the screw channel walls. The small pedicle markers may be used to radiographically confirm position and orientation of the screw sites.


5Measure hole depth



Use the depth gauge to confirm the hole depth and select the appropriate screw length.

Note: The Depth Gauge measures the working length, e.g. if reading 14 mm on the depth gauge, select a 14 mm screw.

6Insert screws


388.395 Screwdriver, hexagonal, long,B2.5 mm

388.391 Holding Sleeve


388.398 Screwdriver with attached Holding Sleeve,B2.5 mm, length 293 mm

388.399 Outer sleeve for Screwdriver, art. no. 388.398

Load the preassembled Axon screw from the screw rack: First engage the hexagonal screwdriver into the screw head and then slide the holding sleeve into place.

Insert the screw.1 After insertion, disengage the screw-driver by first pulling up the holding sleeve.

Surgical Technique

1 For correct screw placement see detailed information in: – CerviFix Surgical Technique (Art. No. 036.000.261) – Aebi M, Thalgott JS, Webb JK (1998) AO ASIF Principles in Spine Surgery.

Berlin: Springer


Option


311.349 Tap for Cancellous Bone Screw

B3.5 mm, for Quick Coupling

389.477 Tap for Cortex Screw,B3.5 mm, for Quick Coupling

388.070 Guide Sleeve for Tap


389.476 Reamer for Axon Screws

Dense bone may be tapped using the tap for 3.5 mm cancellous bone screws or the tap for 3.5 mm cortex screws. To ease screw placement, excess bone may be removed using the reamer.

A 4.0 mm screw may be used if the primary screw has less than optimal fixation.

Insert remaining screws using the same technique.


Surgical Technique

7Contour trial rod


388.868 Trial rod,B3.5 mm

Contour the trial rod to suit the anatomy.

8Bend and cut rod


389.478 Bending Pliers for RodsB3.5 mm


Contour the rod using the bending pliers so that it matches the curve of the trial rod.

Cut the rod to the appropriate length using the cutting pliers.

Precaution: Repetitive or reverse bending may weaken the rod.


9Insert rod


388.407 Holding forceps for rodsB3.5 mm

389.479 Alignment tool



388.349 Rod Pusher


Optional instrument

388.924/388.925 Bending irons, right/left

Insert the rod into the variable axis heads of the screws using the holding forceps. The alignment tool may be used to help to orient the heads to the correct position.

Use the rod pusher/rod insertion instrument to facilitate rod placement and locking screw insertion.

Insert and carefully tighten the Axon locking screws using the screwdriver shaft with the torque limiter.

The bending irons may help to adjust the curve of the rod.

Note: When disengaging the locking screwdriver, provide counterforce by using the rod pusher/rod insertion instrument.


Surgical Technique

10Lock construct




388.349 Rod Pusher


Firmly tighten all locking screws using the screwdriver shaft with the torque limiter to the preset torque of 2 Nm.

To provide countertorque, the rod pusher/rod insertion instrument may be used.

The construct is now rigidly locked.


11Compression/Distraction


388.408 Compression Forceps

388.405 Distraction Forceps



Loosen the locking screws of the level to be adjusted.

Use the compression forceps to achieve compression, or the distraction forceps to achieve distraction.

After compression/distraction is achieved, tighten the locking screws, as described in step 10.

Repeat for each segment as required.


ADDITIONAL TECHNIQUES

Add transverse bars





Place the opening of the 3.5 mm Axon transverse bar over the 3.5 mm rod and introduce the transverse bar into the variable axis head of the screw.

Loosely tighten the set screw of the transverse bar.

Insert the locking screw in the variable axis head as described in steps 9 and 10.

Tighten the set screw of the transverse bar using the hexagonal screwdriver.


Add laminar substitute




To increase rotational stability and protect the dura after laminectomies, add a laminar substitute (laminar clamps and rod). The musculature may be sutured to the laminar substitute. There are two methods:

a Preassembly of construct before insertionInsert a rod of the appropriate length in a left and a right laminar clamp.

Place the laminar substitute on the Axon construct with the holding forceps and lock the set-screws of the lam-ina clamps using the hexagonal screwdriver.

b Assembly in situFirst mount the left and right laminar clamp on the Axon construct, then insert the rod into the clamps and tighten the set-screws.


Additional Techniques

Add transverse connector




388.038 Crimper for Transverse connector

Optional instrument


To increase rotational stability or to protect the dura following laminectomies, add a transverse connector.

The musculature may be sutured to the transverse connector.

Place the appropriate transverse connector on the Axon construct with the holding forceps and lock the set-screws of the lamina clamps using the hexagonal screw-driver.

Lock both swivel ring connections with the clamp, ensur-ing that the gold side of the instrument faces a medial direction.

The transverse connector is now locked rigid.

Note: If necessary, the swivel connection can be loosened with the clamp. Ensure that the gold side of the instrument faces a lateral direction. The rod can be shortened with the cutting pliers for plates and rods.


REMOBILISING VARIABLE AXIS HEADS

Remobilising variable axis heads


388.548 Instrument for Remobilizing of Axon Screws




Remove the locking screws and the rod.

Push the instrument for remobilisation over the variable axis head until the prongs snap over the lower ring.

Squeeze the handle to release the lock.

0123

Synthes GmbHEimattstrasse 34436 OberdorfSwitzerlandTel: +41 61 965 61 11Fax: +41 61 965 66 00www.depuysynthes.com

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 www.depuysynthes.com/ifu ©

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Documents

AXON - synthes.vo.llnwd.netsynthes.vo.llnwd.net/o16/LLNWMB8/INT Mobile/Synthes... · 7.3 Connecting Rods, Pure Titanium (TiCP) • Available in lengths 300 mm and 500 mm Art. No