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Spine SurgeryWhat The Future Holds

Gregory R. Trost, MDProfessor of Neurological Surgery

UWSMPHMadison, WI

Disclosures

• I have no idea what the future holds

• The contents of this talk represent my biased opinions

What Has Not Happened…....Yet

• All spine surgery will be done minimally invasively

• The Perfect Arthroplasty

• Bone Morphogenetic Protein/Biologics

• Cure for SCI or medications to improve outcome

• Robotics in Spine Surgery

• Training the future

• Foolproof Image guidance

What Has Not Happened…....Yet

• Optimal Deformity Treatment

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SCIPathophysiology

• Early - Minutes, Hours, Days

• Late - Weeks

Pathophysiology• Spinal Cord Injury

– Primary injury• Rapid spinal cord compression due to bone displacement,

distraction, acceleration-deceleration, and laceration

– Secondary injury (first postulated by Allen 1911)• Early:

– Vascular changes: loss of autoregulation/ischemia– Electrolyte derangements– Accumulation of neurotransmitters– Inflammation– Reactive oxygen species– Immune Response/Cytokines

• Late:– Apoptosis– Demyelination– Glial Scar Formation

Biochemical Cascade

• Minutes to hours: Ischemia, Excitotoxicity, Depolarization, Reactive Oxygen Species

• Hours to days: Inflammation and Edema

• Days to weeks: Immune Response, Genetic changes, Apoptosis, Glial scar (inhibitory molecules)

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Biochemical Cascade Multimodal Paradigms

• Neuroprotection - ameliorate secondary injuries

• Neuroregenerative – remyelination, axonal and neural regeneration

• Stem cells aimed at regenerative pathways

Spinal Cord Injury

• I think the era of methylprednisolone has passed.

• Hypothermia

• Currently Riluzole is being investigated and holds some promise

• Stem cells-either endogenous or exogenous

Deformity

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ASA Grade and Spine Surgery Outcomes

22857 Patients

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Revision Surgery• Complication rates

for revision spinal fusion are as high as 60%

• Surgery for correction of sagittal imbalance: 47% of patients have residual sagittal deformity

Potter et al: Prevention and Management of Iatrogenic Flatback Deformity. JBJS (American) 2004

The Primary Determinant of Outcome in ADS is Sagittal

Contour

•Yet, Consideration of Global Balance

Glassman SD, Berven S, Bridwell K,Horton W, Dimar JR. Correlation of radiographic parameters and clinical symptoms in adult scoliosis. Spine.2005;30:682-8.)

SaF-12 SRS-29 ODI p Value

SVA Moves Anteriorly <0.001

Presence of Lumbar Kyphosis <0.05

Good Fusions / Bad outcomes

•30% of Lumbar Fusions have poor clinical outcomes

•Postfusion pain has been shown to be significantly related to

»Decreased Sacral Slope

Increased Pelvic Tilt

Decreased Lumbar Lordosis

» Pellise et al, Spine 2007, Min et al. J Spinal Dis 2008, Lazennec et al. Eur Spine J, 1999

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Degenerative Spinal DeformityAdvances in Fusion Rates, Circumferential Treatment, Minimizing Tissue Disruption, & Biomaterials:

Have not optimized outcomes.

Normal Limits

•PT should be < PI/2

•SS should be > PI/2

•LL=PI + 10o

PJKPre-op Films Deformity

• The enemy of good enough is perfect

• Has forced us to be aware of iatrogenic deformity

• We have created a new problem

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Is there an Alternative to this? Minimally Invasive Surgery

• Discectomies and TLIF are routinely performed in many centers

• Techniques for deformity, XLIF, and endonasal techniques are gaining popularity

• Literature demonstrates cost savings, but probably no difference in long-term outcomes

MIS

• Skill set remains specialized

• Will continue to have its role in spine surgery and will likely expand, but will not replace open techniques

Argument for Disc Replacement

• Adjacent Segment Disease

• Maintenance of motion

• Relatively low success of fusion for treatment of multiple segments

• No graft site morbidity

• No possibility for disease transmission (Allograft)

• Decreased recuperation period / Early Discharge/Return to normal activities

• Precludes need for bracing requirements

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Review of Recent Literature

• Mixed results regarding adjacent segment disease

• No study shows ACDF better than ACDA

• Several studies claim ACDA better

• Data is not conclusive

• ACDA and ACDF are appropriate treatment in patients with specific indications

Clinical and Radiographic Analysis of an Artificial Cervical Disc: Seven Year Clinical and

Radiographic Outcomes from a Prospective Randomized Controlled Clinical Trial

Vincent C. TraynelisPraveen Mummaneni

Regis HaidJ. Kenneth Burkus

Prestige STNo. of Patients (Cumulative

Rate %)

FusionNo. of Patients (Cumulative

Rate %)P-Value

Secondary Surgery at Treated Level 11 (4.8) 29 (13.7) <0.001

Revision 0 (0.0) 5 (2.1) 0

Removal 8 (3.6) 8 (3.3) 0

Removal- elective 0 (0.0) 13 (7.0)<0.001

Supplemental fixation 0 (0.0) 5 (2.3) 0

Reoperation 4 (1.5) 4 (3.0) 0

Supplemental fixation - BGS

0 (0.0) 7 (3.0) 0

Fusion (n=265)

Prestige ST (n= 276)

*The rows listed below Secondary Surgery at Treated Level indicate the total number of events per treatment.

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Adjacent Level Surgery

• Through 84 months 11 investigational patients (5.4%) and 24 control patients (11.9%) underwent second surgeries that involved adjacent levels (p=0.008)

Arthroplasty

• Lumbar arthroplasty is dead and will remain so.

• Cervical arthroplasty?

Biologics

• Continuous development in several areas

• Significant abuse potential

• Only 1 bone morphogenic protein on the market currently

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file://localhost/.file/id=6571367.9211272

file://localhost/.file/id=6571367.9211287

Robotics

• file://localhost/.file/id=6571367.9212288

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