Approximately
50% of people injured in a motor vehicle collision will never fully recover,
25% develop persistent moderate/severe pain and disability and 25% experience
milder levels of disability. Being able
to differentiate individuals who are likely to recover from those that are not
may help direct the most appropriate and effective treatments. [1]
35 million people are injured or disabled in a motor vehicle crash annually in the United States with a financial impact of $265 billion.[2] 90% of all motor vehicles at speed less than 14 mph and it is in these that whiplash injuries occur. Injury and disability from a car crash have less to do with the degree of vehicle damage and more to do with human factors and change of velocity of the head and upper torso. The most common mechanism of whiplash injury is from a rear-end collision. A summary of the literature on human crash test has demonstrated that a change in velocity of 2.5 mph was sufficient enough to cause symptoms and 8.7 mph was needed to cause damage to a vehicle.
The number of people being injured in a motor vehicle collision annually are on the rise, and the majority of these are collisions that happen at lower speeds which produce the majorities of the whiplash-associated injuries. The most common symptoms following a whiplash related injury included: neck pain, stiffness, headaches, back pain, headache, paresthesia, and neurological deficit. These are among the most common symptoms patients seek chiropractic care for. Many family practitioners and an urgent care center won’t event treat people injured in a car crash. Emergency Centers typically ensure the patient is stable and release them without additional treatments. Chiropractors are typically the most qualified professional to treat patients injured in a car crash. But with a recovery rate of 50%, it’s essential for providers to understand the predictors of poor prognosis.
“Chiropractors are typically the most qualified professional to treat patients injured in a car crash.”
Three factors that
must be considered with any patient with a whiplash related injury are: Risk factors that increase injury likelihood
and severity, factors that complicate care and factors that can predict recovery.
Risk Factors
Risk factors
are pre-deposing factors that increase the risk and severity of someone being
injured in car crash. Risk factors
included:
·
Being
female
·
Head
turned on impact
·
Rear-end
collision
·
Poor
head restraint positioning
·
Unaware
of impending crash
·
Loss
of cervical lordosis
·
Toe-hitch
in rear-end collision
·
Improperly
positioned head restraint
Complicating Factors
Complicating
factors are pre and post-injury factors that complicate and make recover more
challenging. A list of complicating
factors can be found in the International Chiropractic Association’s Best Practices & Practice
Guidelines (Chapter
11, Table 7).
Examples of
complicating factors included:
·
Advanced
age
·
Disc
herniation
·
Obesity
·
Prior
surgery
·
Metabolic
condition
·
Arthritis
·
Prior
spine injury
·
Obesity
·
Scoliosis
·
Congenital
anomalies
Prognostic Factors
Prognostic
factors are factors that can predict recovery vs chronicity. Although there are many predictors of poor
recovery from a whiplash related injury, I’ve picked out eight that are
supported by the highest levels of evidence, systematic reviews, and meta-analysis. Levels of evidence ranges from 7-to-1 with 7
(authority or professional opinion) being the lowest and 1 (systematic reviews
or meta-analysis) being the highest.
8 Predictors
of Poor Recovery Following a Motor Vehicle Collision
1.
Initial
Pain Intensity (NRS, VAS)
2.
Initial
Neck Disability Index (NDI)
3.
Initial
WAD Grade of Injury
4.
Initial
Cervical Range of Motion
5.
Hyeralgesia
(cold, algometer)
6.
Initial
Expectations of Recovery
7.
Post-Crash
Emotional Factors (e.g. catastrophizing)
8.
Muscle
Fatty Infiltration (on MRI)
Initial
Pain Intensity 5.5 / 10: Initial
pain intensity is the #1 predictor that a patient will not fully recover to
pre-injury status. Meta-analysis from 8
cohorts have established a cut off of 5.5 / 10, with initial pain above this
having a six-fold increase in the risk of persistent pain and/or disability at
long-term follow-up.[3-5]
Neck Disability Index Above 15 or 30%: The #2 predictor of poor recovery is initial self-reported NDI of 15 or 30%. NDI is a 10 question, questioner. Each question consists of 6 answers graded 0-5. The total points are added up and then divided by 50. An initial score greater than 30% is a high predictor of poor recovery.[3, 4, 6]
WAD Grade
III: Both the Croft Grading system and the Quebec
Task Force (QTF) has a grading system for whiplash-associated disorders. The Quebec Task Force grading system is
almost a mirror image of Croft’s. For
Croft’s grading system a Grade III includes decreased ROM, some ligamentous
injury and neurological symptoms. I
personally heard Dr. Croft discusses that his grading system was changed from
neurological findings to symptoms. Radicular symptoms included referred pain
from facet injuries which are very common in whiplash related injuries. The QTF
Grade III WAD includes neck and upper back neurological signs including
decreased reflexes, decreased sensation and decreased strength. Having a WAD grade III increases the odds of
being high-risk for poor recovery.[3, 4,
7]
Initial
ROM: Initial decreased active ROM and decreased
ROM measured at 3 months is a high predictor of poor recovery. The clinical outcomes at 2 years can be predicted at 3 months with 76% accuracy in individuals with neck stiffness.[8]
ROM should be measured with DUAL Inclinometer and follow all AMA
Guidelines including proper warmup.
Additionally, ROM naturally decreases with age so ROM should be compared
normal age-related values.[9, 10]
Hyperalgesia:
Hyperalgesia is an enhanced pain response, frequently caused by an injury.
Cold hyperalgesia is a prognostic factor in WAD for long-term pain and
disability. Cold hyperalgesia can be
determined by applying an ice cube to the patient’s neck and having him/her rate
their pain levels after 10 sec of ice application. Using an ice cube has been
found just as effective as using a neurosensory analyzer. The test is done by simply applying ice to
the skin of the cervical paraspinal for 10 sec and repeated 3 times, take the
average pain scale. Any value greater
than 5 is a good predictor of cold hyperalgesia and poor recovery.[11-13]
Expectation
of Recovery: When patients are asked to rate their expectation
for recover (NRS 0-10) on how likely they are to have a complete recovery with
0 being “not likely” and 10 being “very likely” individuals that rate themselves
less likely to have a full recovery are more likely to have a long-term disability
compared to individuals that expect to make a full recovery. The patient’s expectations for recovery are
very important in prognosis for recovery.[14]
Initial
Emotional State: Hyperarousal is when a patient’s body
suddenly kicks into high alert as a result of thinking about their trauma. Even though real danger may not be present,
their body acts as if it is, causing lasting stress after a traumatic event.
Hyperarousal symptoms form 1 of the 3 necessary clusters of symptoms in the
diagnosis and presentation of posttraumatic stress disorder (PTSD).[1, 15,
16]
Hyperarousal
symptoms:
·
Sleeping
problems
·
Difficulties
concentrating
·
Irritability
·
Anger
and anger outburst
·
Panic
·
Constant
anxiety
·
Easily
scared or startled
·
Self-destructive
behavior (ex. drinking too much)
·
A heavy sense of guilt or shame
Catastrophizing
is when someone thinks something is fare worse than it actually is. Reducing catastrophizing is an important
predictor of recovery. The worse the
patient’s initial emotional state the worse the prognosis for a full recovery.
Reducing catastrophizing and improving depression are important predictors of
recovery.[15,
16]
Muscular
Fatty Infiltration (on MRI): The aging process causes skeletal muscle mass
to decreased and is replaced by noncontractile connective tissue. Due to a reduction in both the number and size of
muscle fibers and to some extent caused by the progressive neurogenic process. The expression of fat cells is the result of
an injury-induced inflammatory response.
After an injury, there is an increase in pro-inflammatory cytokines that
can stimulate the trans-differentiation into adipose tissue. There is a significantly greater fatty
infiltration in neck extensor muscles, especially in the upper cervical spine,
in subjects with persistent WAD when compared to healthy controls.[17] Fatty infiltration in lumbar
multifidus muscle is also strongly associated with chronic low back pain.[18]
Time and
Chronic Pain: Expectation of recovery from WAD after 3
months is also greatly reduced. After 3
months of pain frequently becomes chronic. Altered
central pain modulation is a major pain mechanism in chronic musculoskeletal
pain disorders and is associated with poor outcomes. Central Sensitization (Central Pain Syndrome)
is a term used to describe when the pain becomes “engrained” into the central
nervous system. Individuals with central
sensitization become very hypersensitive and in a state constant/chronic
painful stimuli increasing their pain level and risk of chronicity.[19,
20]
An understanding of risk factors, complicating factors and prognostic factors are critical in treating patients injured in a motor vehicle collision. Not only does it help understand with causation, it helps predictor patient recovery, direct appropriate treatment and can be used to establish future needs once a patient has reached MMI.
About Arthur: Dr. Chris Gubbels is a Fort Collins Chiropractor located at Square ONE which specializes in non-surgical treatment of scoliosis and scoliosis bracing. He has published research on non-surgical treatments of spine deformities and presented cases at international research conferences on non-surgical scoliosis treatment. To learn more about Square ONE visit www.squareonehealth.com.
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2. Association For Safe International Road
Travel. Available from: https://www.asirt.org/.
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