A N D R E W D . P E R R O N , M D , F A C E P P R O F E S S O R A N D R E S I D E N C Y P R O G R A M D I R E C T O R

D E P T O F E M E R G E N C Y M E D I C I N EM A I N E M E D I C A L C E N T E R

P O R T L A N D , M E

Spinal Pathology: Striking the right “cord” with your diagnostic skills

Plan?

Where are we going ? Hx and PE Studies Bad Guys

Infection Trauma Cancer

Where aren’t we going ? AAA / Pyelo / Zoster

30 Minutes!

Back Pain in the ED: Our Job

Find the few who harbor significant pathology (look for “Red Flags”). Take a real history. Do a real examination. When you find something, go after it! Don’t get complacent…there are a few needles in that

haystack. Reassure the vast majority who don’t have

pathology

Back Pain in the ED: Fun facts

Approximately 1-5 in 100 will have a specific diagnosis

Approximately 1 in 200 will need surgery By 4 weeks, 74% will be symptom free By 3 months, 93% of patients will be

without symptoms.

The History: Search for Red Flags

Presence of even 1 red flag increases chance of finding pathology up to 10%

Age < 18: It is unusual for children / teens to complain of back pain.

Etiologies include: Congenital/Developmental abnormalities Tumor Infection Stress fractures (Spondylitis)

> 50: Subject to all the usual major diseases: Cancer AAA Compression fx Pyelo etc

The History: Search for Red Flags

Immunosuppression Fever/Chills/Night Sweats IVDA (IV Drug Abuse)

Vertebral OsteoEpidural Abscess

Unexplained Weight Loss> 10 Lbs over 3 months w/o trying

Night time pain/Pain wakes patient Bowel/Bladder Dysfunction Overflow incontinence

Trauma Usually major, with exception in elderly

Recurrent GU infections Cancer history Pain duration Pain > 4-6 weeks more concerning

The History: Search for Red Flags

Red Flags - Controversy

Maybe the importance of “red flags” is less than we think?

They are not that sensitive nor specific. Many studies disagree on which ones “count most” Trauma = old age and steroids Malignancy = Hx of cancer

Downie A et al: Red flags to screen for malignancy and fracture in patients with low back pain: systematic review. BMJ 2013;347:7095.

Underwood M et al: Red flags for back pain-A popular idea that didn’t work and should be removed from guidelines. BMJ 2013;347:7432.

Physical Exam

The very obvious statement: If you are worried about a spinal problem do enough of a neurological examination to actually find it.

“Neuro WNL” is rarely sufficient Say what you test, test what you say…if they have

5/5 delt /bi/tri/grip then say that. If they can walk / heel walk / toe walk / squat and

stand say that If you find a deficit that you can’t explain then go

after it.

Physical Examination

VS - temperature. Fever, if present can be helpful. Caveat #1: 2%-10% of pts ultimately diagnosed with

mechanical LBP will have fever on presentation from unrelated illness.

Caveat #2: Lots of items on the ddx also cause feverPyelo, pneumonia, prostatitis, diverticular dz

Sensitivity of fever varies with disease process TB = 27%Osteo = 50% SEA = 83%

Physical Examination

Focal/Point Tenderness ? Utility Not studied Kappa is terrible

Evidence of trauma Evidence for alternative diagnoses Spasm (?) Studied Kappa is horrible for agreement of presence/absence, and if

present, on which side. Johnson EW: The myth of skeletal muscle spasm. Am J Phys

Med Rehabil 1989;68:1.

Neurologic Examination

A few simple tests will rule out pathology in the vast majority.

Need to assess motor/sensory/reflexes on all

Need to assess bowel/bladder function on some. Need to ask for it in all. (rectal/saddle/etc)

Bowel/Bladder complaints

Bowel: Rectal exam for tone/squeeze Anal wink S2-4 reflex

Bladder: Check Post-Void Residual. A PVR < 100 cc’s is VERY

sensitive for ruling out bladder dysfunction. (nl = 9.5 ml., and 25th and 75th percentiles equal to 2.5 and 35.4) US formula = L x W x 6 (in CC’s)

Diagnostics: Plain X-rays

In the absence of Red Flags, plain radiographs are NOT indicated in the 1st 4-6 weeks of back pain, because the VAST majority will be asymptomatic by this time. Supported by AHRQ (Agency for Healthcare

Research & Quality) 2002

The yield for significant unexpected findings on plain films in patients with LBP and no red flags is 1 in 2500.

Liang Arch Int Med 1982

Diagnostics: Plain X-rays

This “conservative” approach has recently been reaffirmed by the National Physicians Alliance Confirms “no benefit” to early imaging in the absence of

“red flags”

Cites potential harms as

Radiation

Cost

“Patient labeling”

Identification / intervention on incidental findings

Srinivas SV: Arch Int Med 2012

Imaging strategies

2009 Meta-analysis Immediate imaging vs standard care for LBP w/o red flags Even includes immediate imaging with fancy modalities

(CT / MRI) No difference in primary outcomes- pain & function in the

short term (0-3 months) or long term (6-12 months). No difference in secondary outcomes – mental health,

quality of life, pt satisfaction. No serious diagnoses missed in those not imaged

(i.e. w/o red flags)

Chou Lancet 2009

Other Radiographs

MRI - Study of choice if: Disc/Abscess/Metastases suspected. Cauda Equina (bowel/bladder dysfunction) Ligamentous injury

CT - (+/- Myelogram) Study of Choice if: Bony Injury MRI contraindicated Recent spine surgery

What about labs?

In general, felt to be extremely unhelpful in the evaluation of back pain.

Don’t let normal lab values dissuade you from the appropriate tests if you feel they are indicated…none are sensitive enough to do so.

Leukocytosis is present in 40-50% of patients with spinal infection, and 6-10% without infections etiology. “Normal” WBC does not rule out infectious process.

ESR extremely non-specific (elevation = “something is inflamed”). CRP ?

UA can identify alternative diagnoses

Can’t Miss Back Pain Pathology

Infection Spinal Epidural Abscess

Trauma Missed spinal injuries

Cancer Metastases Primary Cancers

Spinal Epidural Abscess

Spinal Epidural Abscess

The Problem with SEA They are hard to find

They are also rare, so they are not on the radar They frequently happen to challenging patient populations

(IVDU, chronic back pain s/p surgery / instrumentation) Presentation can be subtle

Nobody has the “classic triad” of fever + back pain + neuro deficits (ok, 13% do)

They generally need a big test (MRI) to find them Time / availability

They can have a really devastating outcome 5% die Up to 20% left para/ quad

Spinal Epidural Abscess

Who gets them? S/P spinal instrumentation (epidural catheters) Paraspinal injections (steroids / analgesics) IVDU DM HIV Alcoholics Tattoos / acupuncture Infection (contiguous or remote)

2/3 have an identifiable portal of entry, 1/3 do not

Spinal Epidural Abscess

4 Stages to most SEAs (can progress over a day to months) Stage 1: Back pain

We would have to MRI every back pain every time they presented to find all stage 1 SEAs

Stage 2: Back pain + Root pain Stage 3: Back pain + root pain + motor weakness, sensory

deficit, bowel / bladder dysfunction Stage 4: Paralysis

The earlier they are found and treated, the better the outcome. You generally come out of surgery with what you went intosurgery with. Plegia > 24 hours almost never reverses.

Spinal Epidural Abscess

2/3 are due to Staph Aureus (50% MRSA)

Rest due to strep (skin), E Coli (UTI). C/T/L spine can all be affected Usually at multiple levels, and can skip areas Pathology not just due to mechanical

compression…also causes micro-vascular septic thrombophlebitis resulting in occlusion.

Spinal Epidural Abscess

So how do I not miss it? Look for red flags

IVDU, Fever, Infectious Source, Spinal Instrumentation Don’t wait for classic triad (13%) Labs

WBC is NOT helpful (40-50% with elevated wbc) ESR and CRP combined may be useful (small study) They found that if both were normal in a low risk patient they

could stop the work-up. Don’t be a testing nihilist when SEA is legitimately in the Ddx Get the right study

MRI is the right study. CT with myelography ok

Spinal Epidural Abscess

Pearls: If it is high on the differential, keep everyone MOVING (MRI,

consultants). Entropy not ok.

Pitfalls: Not thinking of the disease Inadequate hx / physical (neuro) Getting the wrong test and letting it reassure you

CBC, plain films, CT Delaying imaging Delaying ABX if they have a deficit

Vanc + Flagyl + Ceftazidime (pseudomonas) a good place to start

Trauma

Why do we miss spinal injuries?1. Failure to obtain indicated films2. Inadequate films3. Misinterpretation of the films4. Films fail to adequately visualize the injuries

My suspicion/experience: We don’t miss injuries in the super-injured andneuro deficit group (they get an everything-scan). We don’t miss them in the minor mechanism group (they don’t break their back too often). We miss them in the middle group.

Trauma

2 back pain populations that should make you pause and ask yourself “am I missing something”?

Multiple fractures

Compression fractures vs burst fractures

Trauma

Multiple fractures When I find 1 spinal fracture, what is the chance that there is

another, non-contiguous spinal fracture in this patient?

IT DEPENDS WHOYOU ASK !

Overall about 10%

Trauma

Multiple non-contiguous fractures in the asymptomatic patient?: Heterogeneous populations Heterogeneous mechanisms Heterogeneous imaging Heterogeneous fractures (type and location) Heterogeneous study methodologies

And nobody ever gets an actual careful physical exam

Trauma

Multiple non-contiguous fractures in the asymptomatic patient?: Best case scenario

Terregino et al. found that in conscious patients with a normal mental status and no distracting injuries, the absence of back pain or tenderness had a 95% negative predictive value for TLS fractures

Worst case scenario Sava et al. prospectively compared physical examination findings with

plain films in 537 patients with reliable mental status examinations and found clinical examination to be only 80% sensitive in the identification of TLS fractures.

Cooper et al. reported a review of 183 TLS fractures in patients who were neurologically intact with a Glasgow Coma Scale (GCS) score between 13 and 15. 31% of these patients were recorded as having no pain or tenderness, yet all had fractures.

Trauma

Multiple non-contiguous fractures in the asymptomatic patient?: Once you find one spinal fracture, there is SOME risk of

another non-contiguous fracture. This risk is around 10% (all comers) Asymptomatic vs distracted vs inadequate exam is in the eye of

the beholder. Safest answer is to scan all levels once you find a spinal

fracture. If you are going to rely on physical examination, do a good one,

repeat it, and document it.

Trauma

Compression fractures vs burst fx

Trauma

Compression fractures vs burst fx Fall with flexion / distraction Mid-back pain Imaging obtained Is it a simple compression (stable) or a burst (unstable)? How often are we wrong?

Trauma

Compression fractures vs burst fx

Trauma

Compression fractures vs burst fx: Need a CT to figure out

Compression vs Burst Fx

Compression is a stable 1-column injury Early mobilization PT Pain control

Burst is an unstable 2-3 column injury Majority at T12-L3 10% of the time there is more than 1 burst Loss of 50% or more of canal is a bad prognostic factor Will usually get a brace and sometimes get surgery

Cancer

The spine is a great place to get metastases (80%) or primary cancers (20%).

Presentation can be pain, neurologic dysfunction, metabolic abnormalities (High Ca), or some combination.

Cancer

Vertebral metastases are most common with solid organ cancers 90% of Prostate Ca (@ autopsy) 74% of breast Ca 45% of lung Ca 29% Renal Call + Lymphoma

Resultant spinal compression is much less common, but not rare. Lung, Breast, Multiple Myeloma most common 5-6% of patients who die from their Ca will have a spinal cord

compression syndrome while alive.

20% of patients first find out they have Ca due to back pain or compression

Cancer

Can be lytic or blastic Lytic usually indicates a more aggressive cancer (lung, renal) Blastic / sclerotic usually indicates a slower/ more indolent

process. (prostate, breast)

Once cancer cells are established in the bone, tumor cells can induce a vicious cycle of bone turnover that leads to lytic destruction of good bone and promotes the survival of malignant cells

Cancer

Vertebral column is most common metastatic site Distribution mirrors vertebral volume (e.g. thoracic = most)

Nighttime pain (“red flag”) is the most common symptom. Pain is frequently described as being relieved by activity.

Pain can be local, diffuse, radicular With cord compression, 90% will report a prodrome

of pain (average = 7 weeks of pain before compression sx).

Cancer: Diagnosis

If you are looking for the possibility of metastatic / primary spine tumor, then MRI is the study of choice. Need to image whole spine. 20-30% will have multiple silent

metastases in addition to the index lesion.

If you need to know bony structural integrity, then CT is the study of choice. Mostly involved in surgical planning / prognostication

Cancer: Treatment

Cord compression from Ca is an emergency If I think they have it, they get 10mg IV Decadron before they

go to MRI

Get them a radiation oncologist and a surgeon Radiation can reduce tumor size and decrease cord

compression with many tumors Occasionally they need surgical debulking or stabilization

Wrap-Up

Most back pain is not an emergency…occasionally it is

Know the at-risk populations Know the red flags Know how to do an adequate neurological

examination Get the right test Call the right consultant Keep everyone moving forward

Questions?

perroa@mmc.org