Date post: | 23-Dec-2015 |
Category: |
Documents |
Upload: | beatrice-shelton |
View: | 214 times |
Download: | 0 times |
Neck and Spinal Cord Injury
Alpesh A. Patel MD FACSAssociate Professor
Chief, Orthopaedic Spine SurgeryCo-Director, Northwestern Spine Center
Director, Fellowship in Spinal SurgeryDepartment of Orthopaedic Surgery
Northwestern University Feinberg School of Medicine
Disclosures
ConsultingAmedica, Biomet, DePuy, GE Healthcare, Stryker Spine, Zimmer
Product Design/RoyaltiesAmedica, Ulrich Medical
Stock options/Ownership (<1%)Amedica, Trinity, Nocimed, Cytonics
BoardCervical Spine Research Society, Lumbar Spine Research Society, Indo-American Spine Alliance
Editorial BoardContemporary Spine Surgery, Surgical Neurology International
NMH Spinal Cord Injury Center
• RIC – Midwest Regional Spinal Cord Injury Center
• One of 14 national sites• NIH
Traumatic Spinal Cord Injury
• Cervical spine most common• 12,000 new cases
per year in U.S• Dramatic Injuries• Young, Fearless Population
SCI Grouped Etiology
1973-79 1980-84 1985-89 1990-94 1995-99 2000-04 2005-09 2010-120%
10%
20%
30%
40%
50%
60%
14.4% 14.2%
10.2%7.6% 7.0%
8.8% 8.0% 9.2%
Vehicular Accidents Falls Violence Sports
Year
Perc
enta
ge
Age at Injury and Gender
1973–1979 1980–1984 1985–1989 1990–1994 1995–1999 2000–2004 2005–201220
25
30
35
40
45
Males: 23,442 (80.7%) Females: 5,610 (19.3%)
Falls and SCI
• Fall Risk– Propioceptive dysfunction– Neuropathy– Medications– Medical co-morbidities
• Pre-existing canal stenosis– Spondylotic disease– Asymptomatic
• 25-90% > 60 years old
Boden JBJS 1990Teresi Radiology 1987
Economic Costs
• >170 days of hospitalization - 1st 2 yrs• Direct costs – 12-14 billion US $ per yr• Indirect costs
– Lost wages– Caregivers– Lost productivity
Historical Perspective
• Traction• Bedrest• Benign neglect
“One having a crushed vertebrae in his neck; he is unconscious of his two arms (and) his two legs, (and) he is speechless.
- Translation of the Edwin Smith papyrus, 3000 B.C.
an ailment not to be treated.”
Pathophysiology of Spinal Cord Injury
• Primary mediators:– Direct injury to
spinal cord tissue– Hemorrhage– Ischemia
IntactCord
Acute Spinal Cord Injury
MechanicalForces
PRIMARYINJURY
Acute Pathophysiologic Processes
+
SECONDARYDAMAGE
PRIMARY DAMAGESECONDARY DAMAGE
Past – Timing of Surgery
• No urgency in treatment– “Early treatment” 3-5 days
• Early treatment = risk !– Neurological decline– Cardiopulmonary– Polytrauma
Marshall 1985, Vaccaro 1997, Mirza 1999, McKinley 2004…
Benefits of Early Surgery
• Neurological protection• Early stabilization• Quicker and safer mobilization• Decreased morbidity
– ICU stay– Pulmonary complications– GI complications
Schlegel, J. Orth. Trauma, 1996
Animal Data
• Primate– Kobrine et al 1978, 1979
• Feline– Brodkey et al 1972– Croft et al 1972
• Canine– Bohlman et al 1979– Delamarter et al 1995– Carlson et al1997, 2003
• Rats– Guha et al 1987– Zhang et al 1993– Dimar et al 1999
• Multicenter, Non-randomized• 2002 to 2009• Acute Cervical SCI – 313 patients
– 182 Early (<24 hours): mean 14.2 hr– 131 Late (>24 hours): mean 48.3 hr
Current Interventions
• Surgical decompression• Optimizing spinal cord perfusion• Steroids• Hypothermia
Spinal Cord Circulation
Tator CH. Review of experimental spinal cord injury with emphasis on the local and systemic circulatory effects. Neurochirurgie 1991; 37:291-301. Tator CH, Fehlings MG. Review of the secondary injury theory of acute spinal cord trauma with emphasis on vascular mechanisms. J Neurosurg 1991; 75:15-26.
• Decline in Blood Flow After Trauma– Autoregulation disrupted by
trauma– Systemic hypotension
• Post-Traumatic Ischemia and Infarction– Microcirculatory changes– Blood flow drops to < 20
cc/100g/min within 2 hrs– Vascular congestion & vasogenic
edema– Neurogenic shock
Spinal Cord Perfusion
• PRESERVE cord perfusion• PRESERVE neuro function• AVOID
– Hypotension– Anemia
• No strong published guidelines
Spinal Cord Perfusion
• Mean arterial pressure >80– Optimize Volume (CVP)– Pressure support
• Hematocrit >30• Duration
– 3-7 days– ICU care
NASCIS II and III High Dose Methylprednisolone
IV bolus: 30 mg/kg Continuous infusion: 5.4 mg/kg/hr
If steroids given: Duration0-3 hrs post injury 24 hrs3-8 hrs post injury 48 hrs
Bracken, et al. JAMA 1997Bracken, et al. N Engl J Med 1990
NASCIS Limitations
• Methodology– Post hoc analysis– Arbitrary time cut-offs
• Transparency– Private data
• Objectivity– Drug sponsored studies– COMPLICATIONS
High Dose Steroids
• AVOID steroids in:– Neurologically intact– Nerve root injuries– Patients > 3-8 hours from injury– Gun shot wounds– Penetrating trauma– Elderly– Multiply injured– Dose >24 hours
Future Studies• Drug interventions
– TWO at Northwestern• Multi-center trials• IV treatments in patients with Cervical/Thoracic Acute
Spinal Cord Injury
Future Studies• Early detection
– Advance MRI studies: find patients at risk BEFORE they are injured