INDIRECT SPINAL DECOMPRESSION FOR SPINAL STENOSIS

Dr. A. Sivaraman

FRCS(Eng) FRCS(Ed) FRCS(Orth)

Consultant Orthopaedic Spinal Surgeon

The Royal London & St Bartholomew's Hospital

Eminence vs. Evidence

Lumbar Lordosis

Part of being human

Laminectomy

Efficacy

0% 25% 50% 75% 100%

Injection Therapy

LSS Treatment Options

Neurogenic Intermittent Claudication - Central - Lateral/foraminal stenosis

Spondylolisthesis (<1.5) with NIC

Kissing Spine / Baastrup

Facet Syndrome

Degenerative and/or iatrogenic (post-discectomy) Disc Syndrome

Contained HNP

Adjacent level syndrome, primary or secondary

Indications

MRI Case Study

Preop > 6 Weeks Postop

Prevents Canal Narrowing

With the X STOP in place:

Canal Area is 18% greater Canal Diameter is 9% greater Subarticular Diameter is 50% greater

Richards et al, ISSLS 2002 Intact, extension X STOP, extension

Prevents Foraminal Narrowing

With the X STOP in place:

Foraminal Area is 25% greater Foraminal Width is 41% greater

Intact, extension X STOP, extension Richards et al, ISSLS 2002

Spinal Kinematics Spinal Kinematics

Axial RotationX STOP = 1.6o

Intact = 1.7o

Lateral BendingX STOP = 8.8o

Intact = 8.2o

X STOP

Flexion/ ExtensionX STOP = 3.1o

Intact = 7.6o

Biomechanical Studies

- Disc Pressure -

Disc Pressure

• L3-4: X STOP in Extension• 63% decrease in posterior annulus

pressure• 41% decrease in nucleus pulposus

pressure• L3-4: X STOP in Neutral

• 38% decrease in posterior annulus pressure

• 20% decrease in nucleus pulposus pressure

• No significant affect on the disc pressures at the adjacent levels

p< 0.05%

Disc Pressure

Biomechanical Studies

- Facet Load -

At the implanted level: Contact Area (43%) Pressure (61%) Peak Pressure (58%) No significant differences

at the adjacent levels

Intact X STOP

L2-3

L3-4

L4-5

Facet Load Results

Transfer of Biomechanical Load

Clinical Experience

Lumbar Spinal Stenosis Clinical Outcome with X-STOPTM : a prospective cohort

Mr.A.Sivaraman Mr.S.Tucker Mr.C.Natali Mr.M.H.Noordeen Royal National orthopaedic hospital, Stanmore EJOST 2007

Methods

Prospective study June 2004 Mean Age: 61.5 (52- 94 yrs) 46 patients 26 Females, 20 Males Neurogenic claudication

Results

Operative time - 50 mins (40-70 mins) for multilevel implantations Hospital stay - 2 days (1.5 - 3 days) Blood loss- < 50 ml No neurological complication

Results Improvement in walking distance - 68%

Improvement in ODI by 12% or more - 90% (p<.0001)

Improvement in SF12 Physical score - 70% (p=.0003)

Improvement in SF12 Mental score - 80%(p=.005)

Consumption of NSAID Stopped - 55% Occasional - 35% Regular use - 10%

Patient satisfaction - 82%

Results

Leg pain

Back pain

ODI SF12 Physical score

SF12 Mental score

Pre 6.7 (0-10)

6.8 (1- 9)

42% (10-82)

11.31 (6- 15)

16.54 (6- 24)

Post 2.7 (0- 7)

2.8 (0- 5)

16.4% (0-58)

16.04 (10- 20)

22.76 (11-27)

MRI Sagittal

Preop Postop

MRI Axial

Preop Postop

Complications

Superficial wound infection - 2 - Settled with oral antibiotic Dysesthesia - 3 Wound haematoma - 1

Technical difficulty - 1

Second Generation

Third Generation Implants

WELLEX™ DYNAMIC LOAD RELATED (50N / 100N) LOAD SHARING INSTEAD OF LOAD BEARING

50N or 100N

Patient Selection

Spinal stenosis Facetal OA Less than Grade 1 Spondylolysthesis Not for L5-S1

Dynamic Stenosis

Grade 1 Spondy

Surgical Technique

Patient Group

APRIL 2009 - TO DATE 42 PATIENTS 4 TWO LEVEL PROCEDURES AVERAGE SURGERY TIME - 30 MTS AVERAGE LOS- overnight

VAS Scores

BACK PAIN • PRE OP- 7.7 • POST OP- 2

LEG PAIN

• PRE OP- 7.4 • POST OP- 1.8

Results ODI Scores

Results SF12 Physical Health Scores

Results SF12 Mental Health Scores

Complications

1 SUPERFICIAL INFECTION 1 DISLOCATION - SUCCESSFUL REVISION

WELLEX™

Over 15 in market Percutaneous approach Facetal syndrome Topping off ….