Canero G., MD, Rome (Italy) Rome American Hospital

S. Feliciano Clinic

www.islass.org

Epidemiology

Degenerative Lumbar Spinal Stenosis (DLSS)

Roughly 8% adult population affected by Degenerative Lumbar Spinal Stenosis (DLSS)

- Hillibrand AS, Rand N; Am Acad Orthop Surg – 1999 7(4)

20% of patients with low back pain (LBP) have a DLSS

- Zucherman et al;Spine – 2005; 30 - Boden et al;JBJS – 1990 72A(3) - Long DM et al; J Spine Disorders 1996 9(1)

DLSS Surgery in over 65 yrs old patients increased a lot over the past 20 years

- Katz JN; Spine 1995 20 (24suppl) - Ciol MA et al; J Am Geriatr Soc 1996 44(3) - Andersson Adult Spine GBJ; The 2° ed. 1997

Pathoanatomy

Degenerative changes:

Ligamentum flavum (hypertrophied enfolding posteriorly)

Pathoanatomy

Degenerative changes:

Facet joints (hypertrophied up to facet subluxation of a degenerative

spondylolisthesis)

Disc space (annular bulging contributing to narrowing of the canal)

Pathophysiology

Canal constriction meccanically affects the cauda nerve bundle and the free flow of cerebrospinal fluid around this bundle

In turn the nerve fiber is constricted and changes occur in the pia-arachnoid

By increasing the demand on the cauda (patient walking), because of mechanical constriction and associated ischemia, nutritional needs of the nerve roots cannot be satisfied

( Watanabe and Parke, J. Neurosurg, 1986)

Clinical findings

Clinical evidence of chronic nerve root irritation and compression with: narrowing of the spinal canal or neural foramina (Imaging +++) without vascular impairment to the lower extremities

Insidious symptoms onset of leg and back pain and paresthesias with ambulation, increasing in extension and relieving in flexion

→ Neurogenic Intermittent Claudication (NIC)

(Verbiest H.; JBJS 1954 -36B(2))

NEUROGENIC INTERMITTENT

CLAUDICATION

Pre Post

Current Treatment Options

Conservative management Physical therapy and drugs

Bracing

Epidural Steroids

Decompression surgery Open tecnique

Mininvasive technique (interspinous device)

Decompression surgery is superior to conservative choice in terms of pain relief and patient satisfation but success rate of surgery vary widely

(23 - 100%) !!!!

Turner J et al.; Spine 1992 17:1-8

Interspinous categories

Standalone

Combined with decompression surgery

Combined with fusion

Interspinous Spacers

- Stand Alone Intespinous Decompression

In-Space Aperius

X-Stop (eXtension Stop)

Stand Alone Interspinous

Decompression Systems (IDS)

- Stand Alone Decompression Systems vs Decompression Surgery:

SF 36 Data for Stand Alone: Superior outcomes at 1 yr

Stromqvist et al.; Spine Journal 2004 vol. 4, issue 5, suppl 1, : S58-59

SF 36 profiles before and 1 yr after spinal stenosis surgery: a prospective comparison of two techniques in

two nations

- Stand Alone Decompression Systems vs conservative:

Better symptoms severity score and patient satisfaction at 2yr (ZCQ)

Zucherman et al.; Spine 2005 30:1351-1358

Stand Alone Interspinous

Decompression

What is Stand Alone?

- Only purpose of surgery is to implant the device

- Pain relief and patient satisfaction based only on the

device implanted

Stand Alone Interspinous

Decompression What indications are best for stand alone?

- Foraminal Stenosis

- DLSS with neurogenic intermittent claudication

- Discogenic pain, black discs

- No indication to a fusion surgery

- Failed conservative treatment ( > 6 months)

Standalone

Mini open

Percutaneous

X-Stop eXtension Stop

Mini Open

Surgical Technique

Mini Open

X-Ray

•Canal area: 18%

•Canal diameter: 9%

•Subarticular diameter: 50%

Post op. Pre op.

Biomechanics

• Foramen area: 25%

• Foramen width: 41%

Biomechanics

Post op. Pre op.

Biomecanical transfer of loads

No overincrease pressure adjacent

Discs

Percutaneous stand alone

sistems

INSPACE

APERIUS

- Percutaneous

- Stand Alone Decompression

System

- Unilateral approach

- Respect thoracolumbar

fascia and sovraspinous

ligament

Aperius™ PercLID

Surgical technique

Percutaneous Trocar Insertion

under C-arm A-P / L-L view

TC post op

The System

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In-Space

Percutaneous

Interspinous Distraction

The implant

Components

1 Core

2 Screw

3 Wires

27

2

3

1

In-situ deployment of the

anchorage

28

When turning the screw

In-Space closes

and the wings are deployed along the spinous processes

In-situ deployment of the

anchorage

29

Technical information

Component Material

1 Core PEEK

2 Wings TAV (Titanium Alloy)

3 Screw TAV

(Titanium Alloy)

30

3

1

2

Technical information PEEK for undisturbed visualisation

TAV to control the correct positioning

of the implant

31

Inspace vs aperius

inspace aperius

Peek

Percutaneous and

miniopen

Possibility to close wings

to remove device

No monouse

instrumentation

access: lateral

Titanium

Percutaneous

No possibility to close

wings to remove device

Monouse instrumentation

Access: posterolateral

Advantages

Postop standing after few hous

Fast functional recovery (no bracing)

Fast return to daily activities

Postop rehabilitation not necessary

Good patient’s satisfaction, compliance

and results if right indications →

Mild to Moderate DLSS

ADVANTAGES: Local Anesthesia

Avoid risks due to general anesthesiological procedures

Pecutaneous Technique

Reduction of operating time (10+/-5 min)

Reduction of risks and complications due to open surgery

(Bigger skin incision, bleeding, bone removal, muscle

damage, Postsurgical scar…)

No sovraspinous ligament removal (in comparison to other

Interspinous Spacers)

Can be used even in spine deformities (scoliosis <25

Cobb angle)

PITFALLS

Device mobilization

Spinosus process fracture

Dural sac tear (avoid in L5-S1)

Very Severe Stenosis (bone spur)

Tethered Cord

Insufficent Decompression

Interspinous Spacers

- Combined with decompression surgery

Coflex (

Indications

STENOSIS

DISCAL HERNIA

LORDOSIS DISORDER

Disc Herniation

Most often encountered at L4-L5

Imaging findings: facets hypertrophy,

slackness of the posterior supra-spinous ligament,

abnormal approximation of the spinous process (kissing spine)

Surgical treatment: Interspinous spacer

with/out Discectomy

Disc herniation

Stenosis

Central, lateral or foraminal stenosis

Surgical treatment : Interspinous spacer with

partial laminectomy, facetectomy and/or

foraminotomy

Stenosis

Stenosis + Static disorder

Ms MOT, 33 years Post-op

Segmental instability

Adjacent to fused level

• Accelerated degeneration of the adjacent segments

• Surgical treatment: topping off above or below the fused segment, to support newly created loads

Interspinous spacer combined with

decompression : advantages Simple and Safe

Good acceptability for surgeons and patients

Dynamic shock absorber allowing optimal mechanical

behavior in compression and flexion

Restorative restores the normal balance to the spine providing

stability and absorbing loads

Mini-invasive

StenoFix

The interspinous

spacer for

after surgical

decompression

The implants

5 sizes, from 8 to 16 mm

Sterile packed

Color coded with the trial

instruments

47

8 10 12 14 16

Anatomical fit

Features Benefits

Cranial radius Fits into the natural concavity of the superior spinous process

Caudal, long, flat surface Enhances the surface of contact with the inferior spinous

process

48

Comparative with Coflex

49

StenoFix Coflex

1. Anatomical fit

StenoFix has through the good anatomical

fit a better surface of contact with the bone

Coflex has in a lot of patients a reduced

point of contact to the cranial spinous

process

StenoFix Coflex

2. Ventral positioning

Stenofix can be pushed more ventrally between

the 2 facets

= better ventral position

Coflex will hit the bony junction

between the laminae and the

spinous processes earlier.

50

10m

m

12

mm

Double implant StenoFix Coflex

3. Two levels implantation

Less wings impingement

The 2 implants can be placed in a good

ventral position.

Wings are not angulated and not staggered

enough.

The second implant cannot reach the same

ventral position as the first inserted implant

51

StenoFix Coflex

4. Ease of use

The larger base of the Stenofix wings allows

an easier insertion between the cranial

spinous process

52

Coflex StenoFix

9mm

7.5mm

StenoFix Coflex

5. Dampening characteristics

Spring designed for a uniform dampening

behavior, independently of where the loads

are transmitted to the implant.

The resulting stiffness of the implant is not

influenced by the implant positioning into

the patient

.

Depending of the anatomical sit of the

Coflex, the body load is transmitted to the

implant at different places from one patient

to the other.

Load transmitted posteriorly implant has

a low stiffness

Load transmitted more ventrally implant

is completely rigid

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High stiffness Low stiffness Uniform stiffness

X-ray Case Example

Interspinous combined with fusion

primaLock

romeo2pad

axle

aspen

Main features

These devices are ancorate to spinous

processes

All devices have the possibility to fill the

interspinous space with bone to obtain

artrodesis

Surgical technique Romeo pad

Perform a midline approach, resecting the supra-spinous and

interspinous ligaments. Use the process preparer and the

curette to clean the contact surface between implant and bone

on both sides of the spinous processes and between the

spinous processes.

The contact surface between the bone and the implant must

be free of tissue, muscles and ligaments.!

Insert the trial implant in order to determine the

correct size of the device.

Connect the plate with the PEEK cage

without clipping it yet, in order to ensure

maximum space between the plates to

facilitate the insertion of the implant

between the spinous processes.

Connect the implant to the implant holder by

screwing the threaded shaft into the PEEK

cylinder

Use the compression forceps to squeeze the

implant and

fix it on the spinous processes.

The implant has two hollows on each side that

receive

the tips of the tightener to secure the

connection. !

.

Final construct

These devices deliver simplified posterior stabilization and

renewed anatomical alignment for the following seven different

constructs.

Posterior Interlaminar Fusion with the Device

Posterolateral Fusion with the Device

ALIF with the Device

TLIF with Unilateral Pedicle Screws and the Device

TLIF with the Device

Hybrid Constructs/Revision Procedures

Direct Lateral with the Device

Benefits

Minimally invasive fusion device

Provides efficient and optimal placement for secure fixation

Innovative design accommodates wide range of anatomical variation

Integrated bone graft enclosure

Past: Anatomy’s Lesson of Doctor Tulip (Rembrandt, 1632)

Future Focusing: Less is More