SLIDE 1:
SPINE AND SPINAL CORD INJURY IN MOTOR VEHICLE CRASHES:   
A FUNCTION OF CHANGE IN VELOCITY AND ENERGY DISSIPATION ON IMPACT WITH RESPECT TO THE DIRECTION OF CRASH: KEY DETERMINANTS OF THE PATTERN OF ASSOCIATED INJURIES AND PATIENT OUTCOMES. A CRASH INJURY RESEARCH ENGINEERING NETWORK (CIREN) STUDY

      JOYCE A. SMITH, MS,
      JOHN H. SIEGEL, MD,
      SHABANA Q. SIDDIQI, MD
NEW JERSEY MEDICAL SCHOOL CIREN CENTER


SLIDES 2-3:
In addition to the NJ CIREN Center, data included was collected by 9 other CIREN Center Principal Investigators: 

University of Alabama Birmingham
Loring W. Rue, MD 

Childrens National Medical Center
Martin Eichelberger, MD

Honda Inova Fairfax
Samir Fakhry, MD
Dorraine D. Watts, PhD

Harborview Injury Prevention and Research Center
Charles Mock, MD
Fred Rivara, MD
David Grossman, MD

William Lehman Injury Research Center
Jeffrey S. Augenstein, MD


University of Michigan 
Stewart Wang, MD
Larry Schneider, PhD 

National Study Center for Trauma and EMS
Patricia Dischinger, PhD
Andrew Burgess, MD
Jim OConnor, MD

San Diego County Trauma System
A. Brent Eastman, MD
David B. Hoyt, MD
Gail Cooper, PhD

MCW - Froedtert Hospital
Thomas Gennarelli, MD



SLIDE 4:
CIREN Network - map


SLIDE 5:
INTRODUCTION I

THE CONSEQUENCES OF SPINE AND SPINAL CORD INJURY WERE FIRST DESCRIBED IN THE SMITH PAPYRUS, FROM THE OLD KINGDOM OF EGYPT (3000-2500 BCE).

If thou examinest a man having a dislocation in a vertebra of the neck, shouldst thou find him unconscious of his two arms (and) his two legs on account of it, while his phallus is erected on account of it, (and) urine drops from his member without his knowing it; it is An ailment not to be treated.

GALEN, A PHYSICIAN IN 2ND CENTURY AD, DEMONSTRATED PARALYTIC EFFECTS OF CERVICAL SPINAL CORD TRANSECTION AT DIFFERENT LEVELS.

He showed that transection of the cord below the  4th cervical vertebra allowed some voluntary respiration, but transection above the 3rd vertebra abolished respiration by paralysis of the diaphragm.


SLIDE 6:
INTRODUCTION II

PRIOR TO THE MECHANIZED AGE, SPINAL COLUMN AND SPINAL CORD INJURIES WERE MOST COMMONLY RELATED TO FALLS OR SECONDARY TO BLOWS TO THE BACK.  WITH THE ADVENT OF THE MODERN ERA, THE MAJOR CAUSE OF NON- PENETRATING SPINE INJURIES HAS BEEN CONSEQUENT TO MOTOR VEHICLE CRASHES. RECENT REPORTS FROM THE UK SHOWED 14% OF CAR CRASH OCCUPANTS SUSTAINED A SPINE FRACTURE (SF).  A CANADIAN STUDY HAS SHOWN THAT 59% OF THEIR SF CASES HAD A CERVICAL SF DUE TO A MVC. 


SLIDE 7:
MATERIALS & METHODS I

PATIENT:

1) AGE, SEX, HEIGHT & WEIGHT
2) DIRECTION OF CRASH FMVC OR LMVC
3) OCCUPANT VEHICLE (V1) VS OTHER VEHICLE (V2) OR NON-VEHICLE (FO)
4) SEAT-BELT AND AIRBAG DEPLOYMENT
5) SURVIVAL OR DEATH STATUS
6) PATIENT OR NEXT OF KIN INFORMED CONSENT OR                   
7) MEDICAL EXAMINERS AUTHORITY FOR SCENE FATAL CRASHES
8) POLICE, EMS & HOSPITAL RECORDS
9) MEDICAL EXAMINER AUTOPSY REPORTS
10) PSYCHOSOCIAL EVALUATION IN HOSPITAL & FOLLOW-UP AT 6, 12 & 18 MONTHS


SLIDE 8:
MATERIALS & METHODS II

VEHICLE:

1) CRASH RECONSTRUCTION DATA FOR MECHANISM OF CRASH WITH SCENE DIAGRAM AND DETERMINATION OF PRIMARY DIRECTION OF FORCE (PDOF) ON SUBJECT VEHICLE (V1)
2) DELINEATION OF SITES OF DRIVER AND/OR FRONT SEAT PATIENTS INJURY-PRODUCING CONTACT WITH PASSENGER COMPARTMENT STRUCTURES
3) COMPUTATION OF CHANGE IN VELOCITY ON IMPACT      (DELTA V ) ON V1 VEHICLE
4) COMPUTATION OF IMPACT ENERGY DISSIPATION (IE) ON V1 VEHICLE



SLIDE 9:
MATERIALS & METHODS III
CIREN DATA FROM 1152 ADULT DRIVERS OR FRONT-SEAT OCCUPANTS OF MOTOR VEHICLE CRASHES (MVCs) INVOLVING CARS OR SPORT UTILITY, VANS, OR LIGHT PICK-UP TRUCKS (SUVT).  CRASHES WITH FULL ROLLOVERS, REAR-END COLLISIONS, OR EJECTED PATIENTS EXCLUDED.  NO SIDE AIRBAGS IN SERIES. DATA SPAN PERIOD 1996-2003.  ALL PATIENTS HAD AIS = 3, BUT WITHIN GROUP OF 1152 WERE 214 PATIENTS WITH SPINE FRACTURES (SF) OF AIS = 2.  SOME PATIENTS HAD SPINE FRACTURES IN MORE THAN ONE ANATOMIC REGION SITE: (CERVICAL,THORACIC, OR LUMBAR).
701 FRONTAL MVCs  (PDOF 340 - 0 - 20) RESULTED IN 142 ANATOMIC REGIONAL SITES OF SF.
451 LATERAL MVCs  (PDOF <340 -190 OR >20 -170) RESULTED IN 101 ANATOMIC REGIONAL SITES OF SF. 


SLIDE 10:
age distribution of all MVC Cases N=1152
[bar chart]


SLIDE 11:
TYPE OF MOTOR VEHICLE AND NATURE OF  IMPACTING VEHICLE OR OBJECT IN 201 MVCs IN WHICH PATIENTS WITH SPINAL FRACTURE INJURIES WERE DRIVERS OR FRONT-SEAT PASSINGERS 

FMVC:         	V2=CAR       V2=SUVT           	      FIXED OBJECT
V1=CAR              	27%                18%            		55%      
(N=77) 
V1=SUVT            	11%                22%             		67%
(N=36)
LMVC:          	V2=CAR         V2=SUVT                FIXED OBJECT
V1=CAR             	37%                 33%          		30% 
(N=76)
V1=SUVT           	17%                 25%           		58%
(N=12) 

        IN FRONTAL CRASHES:  REGARDLESS OF WHETHER V1 WAS A CAR OR SUVT, THERE WERE A DISPROPORTIONATE NUMBER OF CRASHES INTO FIXED OBJECTS, IE: BARRIERS, TELEPHONE POLES, OR TREES, WHICH RESULTED IN A SPINAL FRACTURE
       
        IN LATERAL CRASHES:  IF V1 WAS A CAR, THE INCIDENCE OF THE TYPE OF V2, OR IMPACT INTO A FIXED OBJECT WAS EVENLY DISTRIBUTED AS THE CAUSE OF THE SPINAL FRACTURE INJURY.  HOWEVER, IF V1 WAS AN SUVT, A CRASH INTO A FIXED OBJECT WAS THE OVERWHELMING CAUSE OF THE SPINAL FRACTURE INJURY        


SLIDE 12:

COMPUTED CRASH DELTA Vs & IEs
FMVC:   MEDIAN   MEAN & SD       IE
	N=701    45 KPH      47  24.8 KPH   159,679J

SPINE FRACTURE (SF) IN FMVC PATIENTS       CERVICAL SF 	68 PATIENTS
THORACIC SF 	35 PATIENTS
LUMBAR SF 		39 PATIENTS 
	
LMVC:  MEDIAN   MEAN & SD        IE
    N=451     33 KPH     35  19.2 KPH   103,794 J

SPINE FRACTURE (SF) IN LMVC PATIENTS
       CERVICAL SF 		64 PATIENTS
       THORACIC SF 		21 PATIENTS
       LUMBAR SF 		16 PATIENTS



SLIDE 13:
Patients with Frontal Cervical SPine Injuries by Restraint Use and mortality
[scatter chart]


SLIDE 14:
Patients with lateral cervical spine injuries by restraint use and mortality
[scatter chart]

SLIDE 15:
Patients with frontal thoracic spine injuries by restraint use and mortality
[scatter chart]


SLIDE 16:
Patients with lateral thoracic spine injuries by restraint use and mortality
[scatter chart]


SLIDE 17:
Patients with frontal lumbar spine injuries by restraint use and mortality
[scatter chart]


SLIDE 18:
Patients with lateral lumbar spine injuries by restraint use and mortality
[scatter chart]


SLIDE 19:
Patients with cervical spine fractures vs patients with thoracic spine fractures
[double bar-chart]


SLIDE 20:
Patients with thoracic spine fractures vs. patients with lumbar spine fractures {double bar-chart]


SLIDE 21:
Patients with cervical spine fractures vs patients with thoracic spine fractures - Fatalities Only
[double bar-chart]

SLIDE 22:
INCIDENCE OF SPINAL CORD INJURY(SCI) BY REGION OF SF
CERVICAL SCI 33%
THORACIC SCI 18% 
LUMBAR SCI 2%

RELATIONSHIP OF SF & SCI TO DELTA V
FMVC DELTA V MEAN 47.4 KPH:  49% SF, 47% SCI AND 71% SF DEATHS OCCURRED ABOVE FMVC MEAN ?V

LMVC DELTA V MEAN 35.3 KPH:  51% SF, 52% SCI AND 67% SF DEATHS OCCURRED ABOVE LMVC MEAN ?V

OVERALL DEATH RATE IN C-SF 41%.  HOWEVER, 80% OF ALL DEATHS IN SCI OCCURRED IN CERVICAL SF CASES AND IN THESE FATAL SF, 74% ALSO HAD A BRAIN INJURY.

OVERALL DEATH RATE IN Th-SF 42%.  BUT, THORACIC SF DEATHS WERE MAINLY DUE TO BRAIN (45%), THORAX (95%), OR PELVIC FX (50%) INJURIES


SLIDE 23:
SEAT-BELTS AND BACKLOADING
INDUCTION OF LUMBAR, OR THORACIC SPINE FRACTURE WITH SPINAL CORD INJURY: CASE REPORTS

VEHICLE: 1998 HONDA ACCORD IMPACTED CONCRETE BARRIER AT DELTA V OF 76 KPH WITH IE OF 363,060 JOULES

DRIVER: 17 YEAR MALE, 5FT 8 INCH, 140 LBS; LAP-SHOULDER SB  + AB; COMPRESSION FX L1 WITH L1/T12 FX DISLOCATION AND T12 SCI

FRONT-SEAT PASSENGER: 16 YEAR FEMALE, 5FT 5 INCH, 120 LBS; LAP-SHOULDER SB + AB; BURST FX OF L4, NO SCI
 3 REAR SEAT MALE PASSENGERS WEIGHING APPROXIMATELY 150 LBS EACH


SLIDE 24:
[images]
Clockwise from upper left: diagram of seat belt contusions on driver and passenger; dermatomes of spinal cord injury suffered by driver; CT (right) of drivers spine with MRI of normal comparison spine and cord; CT (right) of passengers spine with MRI of normal comparison spine and cord. 


SLIDE 25:
AIRBAG-INDUCED THORACIC SPINE FRACTURE DISLOCATION AND SPINAL CORD TRANSECTION

 VEHICLE (V1): 1997 MERCURY SABLE IN FMVC WITH 1989 FORD TAURUS STATION WAGON (V2) AT DELTA V OF 26 KPH WITH IE OF 47,803 JOULES

 DRIVER: 56 YEAR MALE, 5FT 10 INCH, 320 LBS; ANTERIOR CHEST WALL CLOSE TO STEERING WHEEL AB COVER; NO SB

 UNDEPOWERED AB DEPLOYED, PRODUCING FRACTURE DISLOCATION OF T4 ON T5 WITH COMPLETE MOTOR AND SENSORY LOSS DUE TO SPINAL CORD TRANSECTION



SLIDE 26:
[images: Clockwise from upper left: exterior of case occupants vehicle showing frontal damage; interior of case occupants vehicle showing intrusion into passenger compartment on driver side; dermatomes showing functional loss due to case occupants spinal cord injury; CT showing complete separation between T4 and T5] 


SLIDE 27:
AIRBAG-INDUCED CRANIAL-CERVICAL DISLOCATION AND CERVICAL SPINAL CORD TRANSECTION

 VEHICLE: 1993 FORD MUSTANG TWO-DOOR SPORT CONVERTIBLE (V1), STOPPED ON HIGHWAY, THEN STRUCK FROM BEHIND BY V2 (1996 NISSAN MAXIMA) AT HIGH SPEED WITH INTRUSION INTO REAR OF PASSENGER COMPARTMENT, PUSHING DRIVER INTO CONTACT WITH STEERING WHEEL AND UNDEPLOYED AIRBAG.  THEN ROTATING V1 STRIKES V2 FRONTALLY, WITH ACTIVATION OF FRONTAL UNDEPOWERED AB, BEFORE COMING TO FINAL REST AGAINST A BARRIER.

DRIVER: 31 YEAR FEMALE, 5 FT 4 INCH, 159 LBS; AB DEPLOYMENT PRODUCED CRANIO-CERVICAL DISLOCATION AT ATLANTO-OCCIPITAL JUNCTION WITH COMPLETE SPINAL CORD INJURY AND DISRUPTION/OCCLUSION OF BOTH INTERNAL CAROTIDS AND VERTEBRAL ARTERIES.


SLIDE 28:
[photos- Clockwise from upper left: exterior (rear) of case occupants vehicle showing crush damage; another view of exterior of case occupants vehicle; brain flow study showing no flow; X-ray showing atlanto-occipital dislocation; interior of case occupants vehicle showing driver seat pushed toward steering wheel hub]

SLIDE 29:
INFLUENCE OF RESTRAINT TECHNOLOGY: AIRBAGS & SEATBELTS
INCIDENCE OF SPINAL CORD INJURY AS PERCENTAGE OF SPINE FRACTURES BY VEHICLE MODEL YEAR PERIOD
 FEW AB          AB USE       DEPOWERED AB
1989-1993        1994-1998       1999-2003
  SCI 64%          SCI 54%         SCI 49%

INCIDENCE OF SEATBELT USE IN LUMBAR FRACTURE PATIENTS VS USE IN CERVICAL OR THORACIC FRACTURE PATIENTS:% SB USE: 
CERVICAL 57%, THORACIC 50%, LUMBAR 82%, (p< 0.01)

BACKLOADING BY REAR SEAT PASSENGERS, OR CARGO IDENTIFIED IN 20% OF LUMBAR SF PATIENTS


SLIDE 30:
CONCLUSIONS I
THE MOST COMMON SPINE FRACTURE INJURY IN THIS SERIES APPEARED TO BE OF THE CERVICAL SPINE, AND THIS BONY INJURY ALSO APPEARED TO RESULT IN THE HIGHEST INCIDENCE OF SPINAL CORD INJURY.

WHILE RESTRAINT SYSTEMS, SB AND AB, APPEARED TO OFFER PROTECTION AND SURVIVAL BENEFIT TO PATIENTS WITH SF AND SCI IN FMVCS BELOW THE MEAN DELTA V LEVEL (47 KPH), THE PRESENT SB/AB SYSTEMS DID NOT SIGNIFICANTLY INCREASE PATIENT SURVIVAL ABOVE THIS CRITICAL THRESHOLD LEVEL IN PATIENTS WITH CERVICAL OR THORACIC SPINAL FRACTURES, ESPECIALLY IF THE CERVICAL SF WAS COMPLICATED BY A SPINAL CORD INJURY.


SLIDE 31:
CONCLUSIONS II

HOWEVER, IN THIS SERIES THE VAST MAJORITY OF FMVC SF PATIENTS HAD UNDEPOWERED ABs, AND THEIR SB WAS NOT EQUIPPED WITH A SEATBELT PRETENSIONER. THE EFFECTIVENESS OF SUCH NEWER DEVICES NEEDS TO BE EVALUATED IN THESE INCREASED DELTA V MVCs, WHERE THE INCIDENCE OF CERVICAL SF, SCI AND DEATH IS GREATLY INCREASED.

THERE WERE NO SIDE-CURTAIN ABs IN THIS SERIES AND THEIR BENEFICIAL EFFECTS IN PREVENTING CERVICAL SF AND SCI CAUSED BY LMVCs NEED TO BE SPECIFICALLY EXAMINED IN NEWER VEHICLES CONTAINING THESE IMPROVEMENTS.


SLIDE 32:
CONCLUSIONS III

FINALLY, THE INCREASED INCIDENCE OF THE ASSOCIATION OF THE INCORRECT PLACEMENT OF THE LAP PORTION OF THE LAP-SHOULDER SEAT BELT AND ITS RELATIONSHIP TO BACKLOADING FLEXION INJURIES OF THE LUMBAR AND LOWER THORACIC SPINE NEEDS TO BE FURTHER EXAMINED. 

QUANTITATIVE BIOMECHANICAL STUDIES NEED TO BE DONE WITH RESPECT TO DEFINING THE RELATIONSHIP BETWEEN THESE TWO ENTITIES AND TO PROVIDE DATA  THAT CAN ENHANCE THE DEVELOPMENT OF MORE EFFECTIVE MEASURES TO PREVENT BACKLOADING FLEXION INJURIES.


SLIDE 33:
Thank you for your attention!