SLIDE 1:
Pelvic and Thoracic Injuries in Nearside Impact Crashes: Analysis of Contributory Factors
Allan Tencer, Rob Kaufman, Charles Mock Seattle CIREN team
And
Carol Conroy
San Diego CIREN team
SLIDE 2:
Goal of This Study
To determine whether vehicle design factors relate to thoracic and pelvic injuries from near-side impacts
SLIDE 3:
Background
* Side impacts comprise about 32% of all vehicle crashes with occupants experiencing AIS 3+ injuries.
* Thorax and pelvis are the most likely regions to be injured in near-side impacts (Samaha,03)
* Thoracic and pelvic injuries are probably the result of a limited stroke punch intrusion of the door, (Lau,91 Chung 99).
* The predominant injurious contact in thoracic and pelvic injuries is the door (Samaha, 03).
SLIDE 4:
Background  Variables Affecting Injury
Crash variables
- masses of both vehicles (Terrel, 18th ESV, 03)
- angle of impact
- speed of bullet vehicle
- Stiffness of both vehicles
- Height of contact region on door
Occupant variables
- stature of occupant (Samaha 18th ESV, 03)
- location of occupant
- restraint use
- age of occupant (Austin 18th ESV, 03)
SLIDE 5:
Vehicle Design Variables
(1) 2001 Toyota Sienna
	Weight = 2029 kg
	Door crush = 29.7 cm
	Driver TTI = 69
	pelvic g = 94
	No side airbag
(2) 2002 Toyota Tundra
	Weight = 2229 kg
	Door crush = 29.8 cm
	Driver TTI = 22
	pelvic g =27
	No side airbag
SLIDE 6:
Background Vehicle Variables?
Vehicle weight
Maximum door intrusion (Chung 99)
Location of maximum door intrusion
Peak door acceleration
Peak door velocity (Morris, 01,Viano 89)
Peak relative door to vehicle velocity
Wheelbase (related to vehicle stiffness?)
Armrest (panel) stiffness (Rouhana 89, Viano 91, Deng 96, Cavanaugh 96, Daniel 95, Morris 01)
Dummy H-point to door horizontal distance (Morris,01)
Deployed thoracic airbag (thoracic injuries)
Stiff center console (pelvic injuries)
SLIDE 7:
Basic Question
Which vehicle variables relate to dummy accelerations in side impact collisions?
SLIDE 8:
METHODS
NCAP side impact data
- Standard moving deformable barrier mass, height, angle, and velocity
- Occupant standard DOT SID
- Peak pelvic g and TTI determined as function of vehicle related variables
- Reports on 165 vehicles available at www.dms.dot.gov docket 3835
SLIDE 9:
Methods  Vehicle Door Measurements
SLIDE 10:
Methods  CIREN and NASS
CIREN
 * Scene inspection
 * Vehicle damage, restraint use, PDOF, DV
 * Occupant interior contact locations
 * Medical records, x-rays, imaging studies of injuries
NASS
 * NASS-CDS database
 * side impacts, amount of door intrusion
 * highest AIS (MAIS) score of three regions determined
SLIDE 11:
Results  CIREN Examples
SLIDE 12:
CIREN Side Impact Data
and Case Reviews
SLIDE 13:
Lateral Impact Mechanism Reviews
Intrusion = Injury
skeletal diagrams, indicating locations of:
	- thorax
	- abdominal
	- lateral pelvis
	- bilateral pelvis
	- combination
SLIDE 14:
Case Review
Pre-Standard
	- combination intrusion injury
	- crash scene diagram
SLIDE 15:
Case Review
[exterior vehicle photos post crash]
90's compact sedan
SLIDE 16:
[interior photos post crash]
Lateral door intrusion at chest and pelvis
SLIDE 17:
Lower Lateral Door Intrusion
	- Left acetabular fx
	- Lower lateral door intrusion
SLIDE 18:
Injuries
AIS:	2
REGION:	head
INJURY:	concussion
AIS:	2
REGION:	spine
INJURY:	c1 fracture (non-displaced)
AIS:	4
REGION:	chest
INJURY:	L ribs fractures 3-8 with hemothorax
	pulmonary contusion
	ruptured L diaphragm
AIS:	3
REGION:	pelvis
INJURY:	sacral fx
AIS:	3
REGION:	pelvis
INJURY:	L acetabular Fx
	ISS = 29
SLIDE 19:
Side Impact Standard Improvements
[photos]
Use of side impact beams in doors
SLIDE 20:
Case Review
Protection From Side Impact Beams
- 1997 Compact 2HB
- Minimal intrusion
- No injury to front right restrained passenger
SLIDE 21:
Side Impacts From Larger Vehicles Impact Above Support Beams
SLIDE 22:
Upper Door Panel Intrusion
[photo - 1998 Subaru Impreza vs. SUV]
Most light trucks, vans, and SUVs will collapse the upper door panel, and even override the support beam
SLIDE 23:
Door Intrusion - Thoracic Injuries
SLIDE 24:
Case Review
Scene
 - diagram of crash path
 - "look back" path of travel [photo]
SLIDE 25:
Case Review
[photo - post-crash - Compact Sedan]
 - Front Seat Passenger
 - 74 yr. , Male
 - Lap/Shoulder belt
 - Struck by a large pickup
 - Lateral Direction of Force
SLIDE 26:
Upper Door Panel Intrusion
Case Review
[post-crash photos, interior/exterior, front passenger side]
Compact sedan struck by large pickup truck
SLIDE 27:
Upper Door Panel Intrusion
Case Review
diagram  r-B pillar, R side interior, R window frame as points of contact w/passenger
photo indicating locations of points of contact
SLIDE 28:
Injuries
AIS:	2
REGION:	head
INJURY:	scalp lacertaion
AIS:	3
REGION:	head
INJURY:	R subarachnoid bleed/contusion- parietal/occipital
AIS:	4
REGION:	chest
INJURY:	rib fxs: L 1-3, R 3-9 w/R pneumothorax
AIS:	2
REGION:	abdomen
INJURY:	R perinephric hematoma small
AIS:	2
REGION:	abdomen
INJURY:	pancreatic head lac
	ISS = 29
SLIDE 29:
Hospital Course
77 year old restrained male.    Confused at scene; intubated.
Day 1:      Exploratory laparotomy:
	     	Small hemoperitoneum,
	    	Small R perinephric hematoma
Day 2-25: Prolonged respiratory failure:
	     	Pneumonia
	     	Tracheostomy on day 12
	    	Trach pulled on day 25
Day 26:  Transfer to Geriatrics
Day 32:  Transfer to Rehab
SLIDE 30:
CIREN Thoracic injury summary - copy
SLIDE 31:
Side Impact - Abdominal Injuries
(Associated With the Armrest)
SLIDE 32:
Abdominal Injury Case Review
90's sedan
	Delta V = 15 mph
	Front Right Pass.
	Lap/Shoulder belt
	71 yr. , Female
SLIDE 33:
Abdominal Injury Case Review
Injuries associated with armrest:
	R kidney laceration
	Liver laceration
	Other:
		Splenic laceration
		Flail chest
		ruptured aorta
SLIDE 34:
Abdominal Armrest Injury
Case Review
1998 Jeep Grand Cherokee
SLIDE 35:
Scene Diagram
SLIDE 36:
Vehicle Damage
	Door Extrication - low profile
	Delta V = 15 mph
	PDOF = -80
SLIDE 37:
Demographic - Interior Contacts
	Driver
	Near side SS214 Unrestrained
	30 yr., Female
	58, 140 lbs.
SLIDE 38:
Intrusions
	Left B pillar - 22cm - Lat
	Driver Door - 16cm - Lat
	Roof rail   -  12cm - Lat
SLIDE 39:
Occupant Contacts
	- Upper Door Panel Scuff
	- Protruding Armrest scuffed
	- B pillar / Door panel cracked
SLIDE 40:
Treatment - Hospital Course
28 year old Female: Unrestrained in side impact.  Alert at scene.  Tachypneic (RR 40); tachycardic (125);   SBP 100.  Intubated in field.
Initial Evaluation:
Intubated, BP 145/108
L eye brow laceration
Hospital Course:   					Abdominal CT:  small liver and spleen lacs
Extubated on day of admission
Nonoperative management of pelvic fx
Day 6: Discharged home (WB as tolerated)
SLIDE 41:
Injuries
Face					AIS			L eye brow laceration		1
Chest								L rib fxs (2-12)					w/hemothorax 		  	4
Abdomen
	L liver laceration		2
	Splenic laceration		2
Lower Extremity
	L iliac crest fx (comminuted)	3
	MAIS = 4
	ISS = 29
SLIDE 42:
Injury Contacts
Observation Summary
	L Ribs 2-12 w/ hemothorax
	L sup/inf splenic lacerations
	L liver laceration
	L iliac wing fracture
	L pubic ring fracture
SLIDE 43:
[copy]
CIREN abdominal injury summary:
SLIDE 44:
Side Impacts and Pelvic Injuries
SLIDE 45:
Pelvic Fracture Case Review
SLIDE 46:
Door Panel Intrusion
SLIDE 47:
Pelvic Fractures
SLIDE 48:
Lower Lateral Door Intrusion
Associated With Pelvic Fractures
[post-crash vehicle photos]
injury: Comminuted pubic rami fracture
SLIDE 49:
[interior & exterior post-crash photos]
Left side impact with Light Truck
Unrestrained Driver
SLIDE 50:
[diagram of crash scene]
Case Vehicle - 2001 Toyota Tacoma
Struck by a 1994 Toyota Pickup
[post crash exterior photo of case vehicle]
Case occupant - 21 year old, female
Front right passenger - Lap/shoulder belt
Bilateral Pelvic injuries
SLIDE 51:
Vehicle Inspection
[post crash photos]
Smash Missing-DV = 30kph/18.6mph	 	           BES = 39kph/24.4mph
Lateral PDOF
SLIDE 52:
[post-crash interior photos]
Door panel intrusion = 45 cm/17.7inches
Contact evidence on door/center console
SLIDE 53:
[post-crash photo]
Case Vehicle - 2001 Toyota Tacoma
SLIDE 54:
Pelvis
Comminuted fracture of the superior ramus of the right obturator ring which extends into the pubic symphysis. The fracture also extends into the inferior ramus. Comminuted fracture within the superior ramus of the left obturator ring extending into the pubic symphysis
SLIDE 55:
CIREN Pelvic Injury Summary (copy)
SLIDE 56:
San Diego CIREN Project
Principal Investigators:
David B. Hoyt, MD, FACS
Brent Eastman, MD, FACS
Presenter:	Carol Conroy, MPH, PhD
SLIDE 57:
Research Question
   Are vehicles with raised center consoles associated with pelvic injury in nearside crashes?
SLIDE 58:
Selection Criteria
NASS CDS and CIREN databases used
Identify vehicles with raised center consoles
 - Assumed  no change over +/- 2 model years
 - Assumed console standard equipment
 - Only 1998-2004 model years included
SLIDE 59:
Selection Criteria
Only nearside impact crashes
Only drivers or front right seat passengers included
Only pelvic and hip injuries included
SLIDE 60:
Methods
Missing data excluded from analyses
Injury assessed by Abbreviated Injury Scale (AIS)
Total Delta V used to assess speed at impact
BES used when Total Delta V was missing
SLIDE 61:
Profile :  Occupants with moderate (AIS 2) and serious (AIS 3) pelvic injury in nearside crashes
Mean Age and range
  Console (41 occupants): 	40 years (15-89 yrs)
  No Console / 21 Occupants:	43 years (15-80 yrs)
Gender
  Console (41 occupants):	33 (80% women)
  No Console (21 Occupants):	11 (52% women)
Single pelvic injury
  Console (41 occupants):	16 (39%)
  No Console (21 Occupants):	8 (38%)
Driver
  Console (41 occupants):	29 (71%)
  No Console (21 Occupants):	13 (62%)
Seatbelt Use
  Console (41 occupants):	36 (88%)
  No Console (21 Occupants):	19 (90%)
Total Delta V (kmph)
  Console (41 occupants):	mean 36/median 33
  No Console (21 Occupants):	mean 35/median 31
SLIDE 62:
Moderate (AIS 2) and serious (AIS 3) pelvic injury in nearside crashes by magnitude of intrusion
[bar chart]
SLIDE 63:
Limitations
* Results may not be representative
* Small sample size
* Possible misclassification bias of console status
* NASS intrusion is measured at the maximum point of intrusion on the door panel
	May not be at the occupants seat location
SLIDE 64:
Conclusion
This exploratory study found it may be important to continue researching the role of consoles and pelvic injury in nearside crashes.
SLIDE 65:
Results  CIREN Summary
Thoracic injuries, AIS of 4.2, door panel main injury source, intrusion 34cm, DV of 25 mph.  Injuries multiple rib fractures with hemothorax, or pneumothorax, with lung contusions and lacerations.
Abdominal injuries, AIS of 3.3 armrest main injury source, intrusion 30cm, DV 23 mph.  Injuries, 9 spleen lacerations or contusions, 3 liver lacerations or contusions, 3 kidney contusions, 2 diaphragm lacerations, and 2 retroperitoneal hemorrhage.
Pelvic injuries, AIS of 3, door panel main injury source, intrusion 25cm, DV 22 mph.  Injuries included pelvic fx with 11 involving the sacrum.
SLIDE 66:
Results - Vehicle Variables and Pelvic g
[scatter chart]
Vehicle weight, door intrusion, wheelbase correlate to pelvic g
All variables explain about 58% of pelvic g variation
SLIDE 67:
CIREN Example and Console Data
Pelvic Acceleration and Console Trapping
SLIDE 68:
Results - Peak Pelvic g v Center Console
photos - dummies
without center consoles, 69.4g
sd = 19.7g, n = 41
with center consoles, 77.3g
sd = 21.8g, n = 96
(p = 0.05)
SLIDE 69:
Results - Vehicle Variables and NCAP Thoracic Trauma Index (TTI) [scatter chart]
Vehicle weight and max door velocity correlate to TTI
All variables explain about 41% of TTI variation
SLIDE 70:
Results  NCAP TTI and Thoracic Airbags
Photos:
without thoracic airbag, 63.7g
sd = 20.7g, n = 108
with thoracic airbag, 55.6gsd = 13.7g, n = 54
(p = 0.003)
SLIDE 71:
Results - Is Door Intrusion Related to Vehicle Weight or Wheelbase?
[2 scatter charts]
Door intrusion, weak correlation to wheelbase (r2 = 0.15)
Door intrusion, none to vehicle weight (r2 = 0.003, NS)
SLIDE 72:
Results  Does Peak Pelvic g Correlate to Peak TTI?
[scatter chart]
SLIDE 73:
Results  NASS MAIS v Door Intrusion
[line chart]
SLIDE 74:
Discussion - Limitations
NCAP tests, moving barrier simulates smaller vehicle
NCAP doesnt consider door beam over-ride from high SUV and truck bumpers
More biofidelic dummies than DOT-SID available
TTI may not correlate well with actual injuries
Effects of occupant stature and age not considered
NASS, plot of data only of those in group who were injured (ie AIS 1+)
SLIDE 75:
Summary of Findings
For a given vehicle weight, door intrusion, wheelbase correlate to pelvic g, and door velocity to TTI
Vehicle variables studied only account for 41% of TTI, 58% of pelvic g variation
A center console increases peak pelvic g
A thoracic airbag lowers peak TTI
Real-world crash studies also show correlation of door intrusion and thoracic and pelvic injury
Door intrusion is not directly related to vehicle weight but increases with greater wheelbase
SLIDE 76:
Future Work
There is still considerable debate over appropriate chest injury criteria, Favg * Cmax, Cmax, stored energy (Cheung 99)
Using highly detailed CIREN crash data and data from equivalent NCAP tests, to model actual crashes and compare real life injuries to crash dummy measurements in the same crash