back pain cost effective strategies for distinguishing between benign and life threatening causes

8/10/2019 Back Pain Cost Effective Strategies for Distinguishing Between Benign and Life Threatening Causes

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February 2000Volume 2, Number 2

Authors

David Della-Giustina, MD, FACEPMajor, United States Army; Adjunct Assistant Professorof Emergency and Military Medicine; UniformedServices University of the Health Sciences; Director,Madigan-University of Washington AffiliatedEmergency Medicine Residency, Madigan ArmyMedical Center, Fort Lewis, WA.

Bradford A. Kilcline, MDCaptain, United States Army; Resident, Madigan-University of Washington Affiliated EmergencyMedicine Residency, Madigan Army Medical Center,Fort Lewis, WA.

Mark Denny, MDCaptain, United States Army; Resident, Transitional

Year Program, Madigan Army Medical Center, FortLewis, WA.

Peer Reviewer

Andy J agoda, MD, FACEPAssociate Professor of Emergency Medicine, MountSinai School of Medicine, New York, NY.

CME Objectives

Upon completing this article, you should be able to:1.identify the red flagsof back pain that indicate

serious disease;

2.describe the evaluation of the high-risk patientswith back pain, such as children and patients witha history of cancer;

3.discuss the various treatment regimens for thepatient with lumbosacral strain and sciatica; and

4.describe the treatment and evaluation planfor the patient with suspected epiduralcompression syndrome.

Date o f orig inal release: Februa ry 1, 2000.Date of mo st recent review: Janu ary 26, 2000.

See Physician CME Informa tion o n b ack pa ge.

Editor-in-Chief

Stephen A. Colucciello, MD, FACEP,Director of Clinical Services, De-partment of EmergencyMedicine, Carolinas MedicalCenter, Charlotte, NC; AssistantClinical Professor, Department of Emergency Med-icine, Universityof North Carolina at Chapel Hill,Chapel Hill, NC.

Associate Editor

Andy Jagoda, MD, FACEP, AssociateProfessor of EmergencyMedicine, Mount Sinai School of Medicine, New York, NY.

Editorial Board

Judith C. Brillman, MD, ResidencyDirector, Associate Professor,Department of Emergency

Medicine, The University of New Mexico Health SciencesCenter School of Medicine,

Albuquerque, NM.W. Richard Bukata, MD, Assistant

Clinical Professor, EmergencyMedicine, Los Angeles County/USC Medical Center, Los Angeles,CA; Medical Director, EmergencyDepartment, San GabrielValley Medical Center, SanGabriel, CA.

Francis M. Fesmire, MD, FACEP,Director, Chest Pain StrokeCenter, Erlanger Medical Center;Assistant Professor of Medicine,UT College of Medicine,Chattanooga, TN.

Michael J . Gerardi, MD, FACEP,Clinical Assistant Professor,Medicine, University of Medicineand Dentistry of New Jersey;Director, Pediatric EmergencyMedicine, Children s Medical

Center, Atlantic Health System;Chair, Pediatric EmergencyMedicine Committee, ACEP.

Michael A. Gibbs, MD, FACEP,Clinical Instructor, University of North Carolina at Chapel Hill;Medical Director, MedCenter Air,Department of EmergencyMedicine, Carolinas MedicalCenter, Charlotte, NC.

Gregory L. Henry, MD, FACEP, CEO,Medical Practice Risk Assessment,Inc., Ann Arbor, MI; ClinicalProfessor, Section of EmergencyServices, Department of Surgery,University of Michigan MedicalSchool, Ann Arbor, MI; President,American Physicians AssuranceSociety, Ltd., Bridgetown,Barbados, West Indies; PastPresident, ACEP.

Jerome R. Hoffman, MA, MD, FACEP,Professor of Medicine/Emergency Medicine, UCLA

School of Medicine; AttendingPhysician, UCLA EmergencyMedicine Center;

Co-Director, The DoctoringProgram, UCLA School of Medicine, Los Angeles, CA.

John A. Marx, MD, Chair and Chief,Department of EmergencyMedicine, Carolinas MedicalCenter, Charlotte, NC; ClinicalProfessor, Department of Emergency Medicine, Universityof North Carolina at Chapel Hill,Chapel Hill, NC.

Michael S. Radeos, MD, FACEP,Attending Physician inEmergency Medicine, LincolnHospital, Bronx, NY; ResearchFellow in Emergency Medicine,Massachusetts General Hospital,Boston, MA; Research Fellow inRespiratory Epidemiology,Channing Lab, Boston, MA.

Steven G. Rothrock, MD, FACEP,

FAAP, Assistant Professor of Emergency Medicine, Universityof Florida; Orlando Regional

Medical Center, Orlando, FL.Alfred Sacchetti , MD, FACEP,

Research Director, Our Lady of Lourdes Medical Center, Camden,NJ; Assistant Clinical Professorof Emergency Medicine,

Thomas Jefferson University,Philadelphia, PA.

Corey M. Slovis, MD, FACP, FACEP,Department of EmergencyMedicine, Vanderbilt UniversityHospital, Nashville, TN.

Mark Smith, MD, Chairman,Department of EmergencyMedicine, Washington HospitalCenter, Washington, DC.

Thomas E. Terndrup, MD, Professorand Chair, Department of Emergency Medicine, Universityof Alabama at Birmingham,Birmingham, AL.

E MERGENCY M EDICINE PRACTICEA N E V I D E N C E- B A S ED A P P ROA C H T O E M E R GE N CY M E D I C I N E

Back Pain: Cost-EffectiveStrategies For DistinguishingBetween Benign AndLife-Threatening Causes

FEW emergency physicians can work an entire shift without seeing atleast one patient with back pain. Yet, the mere glimpse of this chief complaint on the chart fills many emergency physicians with dread.Imagine this scenario.

A busy shift, a full rack. The eager emergency physician reaches for

the next chart. Bad lucka back pain case. With growing trepidation, thephysicians eyes leap to the allergies field; the patient is allergic toibuprofen, Toradol, and all nonsteroidals. The anxiety heightens as hescans the previous visit fieldoh no, the second visit in two weeks! Hecautiously glances to see if anyone is watching, then surreptitiouslyplaces the chart back in the rack and reaches for the next.

What inspires this visceral fear? Is it anticipation of anotherargument over narcotics? Is it that patients with back pain neverhave anything bad, so they dont need to be in the ED? Alternatively,are we fatalists, believing theres little hope for a curewhich makesus feel inadequate, or perhaps fearful that the patient will view usas inadequate?

No matter the reason, the pandemic of back pain is an inescapable

reality in the ED. And despite the occasional drug seeker who bemoanshis back in an attempt to secure narcotics, each year millions of Ameri-cans suffer genuine agony from back complaints. Some present to the EDwith life-threatening conditions. The emergency physician needs toapproach back pain in a manner that will reduce suffering, minimize thecost and evaluation time for the patient, and yet not miss serious disease.

Disclaimer: The opinions and assertion s conta ined herein are the private views of the auth ors and should n ot be construed as official or as reflecting the views of the Depart ment o f Army or the Depart ment of Defense.


2/24Emergency Medicine Practice 2 February 2000

Studies show that emergency physicians frequentlyorder unnecessary diagnostic tests, prescribe unneces-sary bedrest, and over-refer to specialists, when facedwith patients with low back pain. 1

This article will review the evaluation and treat-ment of back pain as it presents to the ED. A majorfocus of this article is the red flags of back pain.These aspects of the history and physical examinationsuggest serious etiologies. By concentrating on the redflags, the emergency physician can rapidly evaluateand treat back pain without overlooking grave disease.

Epidemiology

Back pain has an annual incidence of 5% in adults andaffects up to 90% of the general population at sometime in their lives. 2 It is second only to upper respira-tory illness as a reason for primary care office visits. 3

Patients may come to the ED because the symptomseither occur or worsen when primary care appoint-ments are unavailable, or because the patient has noprimary care physician. In 1990, the annual cost in the

United States for diagnosing and treating low backpain approached $23.5 billion. 4 When one adds indirectcosts such as compensation, legal fees, and lostproductivity, the cost in 1990 exceeded $50 billion. 4

ED Evaluation: Using The Red Flags Approach

In the ED, the evaluation of patients with low backpain must identify red flags in the history and phys-ical exam. (See Table 1 .) Specifically, the emergencyphysician must be able to recognize life threats such asruptured abdominal aortic aneurysm (AAA), as well asother serious pathology such as epidural compressionsyndromes (spinal cord, cauda equina, conusmedullaris), spinal fracture, infection, and malignancy.

While a search for red flags and directed testing isthe most efficient known approach to the complaint of acute low back pain, it has its limitations. One majorreview found that the diagnostic accuracy of individualitems of history taking, physical examination, anderythrocyte sedimentation rate are poor for predictingradiculopathy, vertebral neoplasms, and ankylosingspondylitis. 5 However, the review noted that thecombined history and the erythrocyte sedimentationrate had relatively high diagnostic accuracy in verte-

bral cancer. Getting out of bed at night and reducedlateral mobility were moderately accurate in detectingankylosing spondylitis.

Other studies confirm the fact that a combination of historical factors suggests serious disease. In one study,the highest combination of sensitivity (.87) andspecificity (.50) for a serious etiology of back diseaseoccurred with any combination of: unable to sleep,awakened and unable to fall back to sleep, medication

required to sleep, and pain worsened by walking.6

The Red Flags In The HistoryAge Is the patient younger than 18 years or older than 50years? In both the old and the young, cancer is a morecommon etiology for back pain. In children, lumbosac-ral strain is rare, with the most common cause of backpain in adolescent athletes being spondylolysis orspondylolisthesis. 7 Spondylolysis is a defect betweensuperior articular process and the lamina of thevertebral body. When this is bilateral, the involvedvertebra may slip forward (spondylolisthesis).

In the older patient, the emergency physicianshould always consider AAA as the etiology for thesymptoms. In one series, back pain alone or in combi-nation with abdominal pain was present in 53% of those with ruptured AAA and in 63% of patientsrequiring surgery for AAA. 8

Dura tion And Acuity Sudden-onset pain is compatible with AAA and renalcolic. While mechanical low back pain may also beacute, most patients with lumbago complain of progressive symptoms. The majority of patients with

Table 1. Red Flags In Patients With Back Pain.

Red Flags In The History

Red Flag ConcernAge less than 18 Spondylolysis, spondylolisthesis,

discitis, spinal infection, tumor,developmental disorders

Age greater than 50 Malignancy, fracture, AAA Trauma FractureChronic steroid use FractureHistory of cancer Malignancy (metastases)Fever, chills, night sweats Infection, malignancyWeight loss Malignancy, infectionInjection drug use InfectionImmunocompromise InfectionNight pain Malignancy, infection,

ankylosing spondylitisUnrelenting pain Malignancy, infectionIncontinence Epidural compression syndromeSaddle anesthesia Epidural compression syndromeBilateral neurologic deficit Epidural compression syndromeUnilateral neurologic Herniated discdeficit

Red Flags In The Physical Exam ina tion

Red Flag ConcernFever Infection, malignancyAnal sphincter laxity Epidural compression syndromeSaddle anesthesia Epidural compression syndromeMotor weakness Epidural compression syndrome,

herniated discAbsent or Epidural compression syndrome,diminished reflex herniated discPositive SLR test Herniated discPositive crossed SLR test Herniated discBone tenderness Fracture, infectionPositive Babinski s sign Upper motor neuron disorder,

spinal cord compression


3/243 Emergency Medicine PracticeFebruary 2000

lumbosacral sprain (LSS) will resolve or have signifi-cant improvement in their symptoms within sixweeks. 9,10 Pain that lasts greater than six weeks sug-gests infection or malignancy. 11-13 Moreover, those withsymptoms of more than six weeks duration are lesslikely to respond to usual conservative management.

Character Of Pain Discomfort due to LSS is usually well-localized to the back and upper buttocks. Pain that radiates into the legor foot indicates lumbar or sacral nerve root compres-sion and may require further diagnostic studies,usually on an outpatient basis. Pain radiating to thegroin can occur with both renal colic and AAA. It isclassically taught that the pain of malignancy orinfection does not improve with lying flat and resting,or is worse at night. Likewise, unrelenting pain despiteadequate treatment and analgesics raises concern forserious disease.

Locat ion Of Pain

While no well-designed studies address this issue, caseseries and textbook lore suggest the location of thepain will narrow the differential diagnosis. Painconfined to the mid and upper back may be related tochest pathology, such as thoracic dissection, myocar-dial ischemia, and pulmonary embolism. Abdominaldisorders such as cholecystitis, pancreatitis, and pepticulcer disease are thought to radiate more to the mid- back. Pelvic pathology produces pain in either thelower abdomen, lower back, or both.

Associated Symp tom s Constitutional symptoms such as fever, chills, night

sweats, and unexplained weight loss suggest eithermalignancy and infection. 11,12,14 Associated symptomsoutside of the musculoskeletal system are also impor-tant to elicit. Specifically, urinary, pulmonary, orgastrointestinal complaints point to diagnoses such aspyelonephritis, pneumonia, pancreatitis, or cholelithi-asis. Most importantly, inquire about neurologiccomplaints. Target questions toward any new inconti-nence (bowel or bladder), erectile dysfunction, lower-extremity weakness or numbness, and saddle anesthe-sia. Patients with compression of the distal portion of the spinal cord (the conus medullaris) or the nerveroots in the spinal canal (cauda equina) may complainof acute urinary retention. A neurologic complaintshould inspire a scrupulous neurologic examination inthe ED to determine the presence of cord compressionor cauda equina syndrome.

Past Medical History A history of major trauma (and even minor trauma inthe elderly) can be associated with vertebral fracture.Even strenuous lifting can cause fracture in theosteoporotic elderly. A history of cancer is a red flag forpotential pathologic fracture from vertebral metastasesor tumor involvement of the spinal canal or cord.

Moreover, a history of injection drug use or of animmunocompromised state such as diabetes, organtransplant, or HIV places the patient at an increasedrisk for vertebral osteomyelitis or epidural abscess. 12,14

The Red Flags In The Physical ExamIn a similar manner, the physical examination has itsown red flags. The general appearance of the patient ishelpful. Patients with LSS generally lie flat and still, asmoving, sitting, or standing worsens their pain. Incontrast, the writhing patient may have a spinalinfection or renal colic. 13,15

Vita l Signs Fever in the patient with back pain is concerningand signals potential infection. However, it isvariably sensitive, ranging from 16% to 83%. Thepresence of fever depends upon the location of infection and the specific pathogen involved. 12,14,16,17

Hypotension in the elderly patient with back painmay presage aortic rupture.

Abdominal Exam ination An abdominal exam is especially important whenevaluating low back pain in the elderly. Specifically,one palpates for a pulsatile mass, auscultates for

bruits, and evaluates femoral pulses. This said, physi -cal examination alone is insensitive for AAA. 18 Nearlyhalf of all patients with AAA do not have a palpablemass, 19 and one study suggests that neither bruits norabsent femoral pulses have any predictive value. 20

The Back The back exam begins with inspection. Specifically,

look for erythema, contusions, and previous surgicalscars. Examine the alignment of the back and deter-mine the range of motion. Patients with ankylosingspondylitis may have loss of the normal lumbarlordosis and marked limitation in motion of the lumbarspine. Remember, however, that most forward flexiontakes place at the hips and not necessarily in thelumbar spine. Next, palpate the back with specificattention to point tenderness. Then, percuss eachvertebral body and note specific locations of tender-ness. Percussion tenderness of the vertebral bodies iscommon with fractures and infection.15,17,21,22 This localiza-tion of pain guides the interpretation of radiographs.

Neurologic Exam ination An adequate neurologic exam is crucial, as it allowsthe emergency physician to identify potentiallycatastrophic disease. The exam begins with a sensoryexam, which can adequately be accomplished withlight touch and pinprick. If any deficit is noted, formaltesting involving position sense, sharp/dull, as well asvibratory sensation may be helpful. An understandingof the sensory dermatomes (or a copy of the AHCPRTests For Low Back Pain on page 13) provides animportant anatomic reference for sensory loss. A



standard hospital pager set on buzz mode is aconvenient high-tech substitute for a tuning fork (if you dont mind rubbing your beeper on someonesfeet). Saddle anesthesia refers to a common findingin cauda equina syndrome that presents as decreasedsensation over the buttocks, perineum, and proximalmedial thighs.

The muscle groups of the lower extremities areindividually tested against adequate resistance.Having the patient walk on their toes and heels is anexcellent way to determine strength of the involvedmuscles. Testing of the patellar (L2-L4 nerve roots) andAchilles (S1 nerve root) reflexes should follow.Impingement of the L5 nerve root does not produce areflex abnormality (as theres no readily testable reflexfor L5). However, there will be a sensory deficit in theL5 dermatome as well as weakness of the extensorhallucis longus (great toe dorsiflexion).

Babinskis sign is an abnormal reflex that appearswhen upper motor neuron innervation through thecorticospinal tract is lost, as may occur with spinal

cord compression. A positive Babinskis sign involvesextension of the great toe and abduction (spreadingapart) of the other toes with plantar stimulation, ratherthan the normal flexion response. 23

The straight leg raise (SLR) test is helpful inidentifying patients with nerve root compression by aherniated intervertebral disc, also termed a herniatednucleus pulposis (HNP). To perform this test, lie thepatient supine then passively raise the straight leganteriorly from 0 to 70 degrees. A positive test pro-duces radicular pain below the level of the knee, in adermatomal distribution. Isolated back pain triggered bythis maneuver does no t constitute a positive test. Radicular

pain or sciatica worsens with foot dorsiflexion(Lasegues sign) and abates by decreasing the legelevation. A positive test result is approximately 80%sensitive for herniated disc. 2,24

Radicular pain down the symptomatic legwhen elevating the asymptomatic leg is a positivecrossed straight leg test. This finding is highly specific,though insensitive, for herniated disc. 2,24 An importantpoint regarding the straight leg raise test is that itcan be easily and stealthily performed while thepatient is seated, using a similar leg extension andfoot dorsiflexion.

Many conditions other than nerve irritation cancause a positive straight leg raise test, includingmyogenic pain, ischial bursitis, annular tear, andhamstring tightness. One test that may distinguishtrue sciatica is the sciatic stretch test. This maneuvercan remove hamstring irritation as the cause of symptoms. In this test, the examiner raises the lowerextremity with the knee extended until the patientexperiences the leg symptoms. The physician thenlowers the leg several degrees below the point of painand applies popliteal compression. Compression of the popliteal fossa will tether the sciatic nerve. Whenthe leg is elevated a second time, the patient with

sciatica should experience symptoms with fewerdegrees of elevation. 25

Rectal Examina tion The rectal examination will evaluate for rectal tone andsensation, prostatic and rectal masses, and to rule outperi-rectal abscess as the etiology for the pain. 26 Arectal exam is not mandatory for every patient whocomplains of back pain (although its routine use maydecrease ED visits for bcak pain). However, it should

be performed in all patients with neurologic com-plaints or deficits. Poor or absent rectal tone in thepresence of saddle anesthesia indicates an epiduralcompression syndrome, most commonly a caudaequina syndrome.

Pelvic Examina tion Numerous reports and clinical experience show thatpelvic pathology can produce low back pain. However,the evidence-based literature is mute on the indicationsfor pelvic examination in women with low back pain.

Tests For Non-Organic PainIn 1980, Waddell wrote an important paper describingfive physical signs associated with non-organic backpain. He proposed that most patients with provenorganic back pain had only one or none of thesecriteria, while patients with three or more signs werelikely to have non-organic disease. 27 These signs have

been wryly termed yel low f lags.Since that time, Waddells criteria have been used

(some say abused) by physicians in the evaluation of low back pain. (See Table 2 on page 5.) Cynics claimthat patients who meet Waddells criteria are malinger-

ers searching for drugs or disability checks. Others beli eve that patients who display these findings do sounconsciously in an attempt to communicate theirpain. One author suggested the following caveatswhen using Waddells criteria:

1. Because an increase in signs is associated with age,they are not recommended for use in the elderly.

2. Behavioral signs can occur with organic findings.The presence of these signs does not contradictorganic findings.

3. Isolated behavioral signs are not clinically signifi-cant. A cut-off of three or more suggests non-organic pain. 28

Two additional tests are often employed todetermine non-organic diseasethe Hoover and thereverse sciatic tension test. 25

To perform the Hoover test , the examiner places hisor her hand under the heel of one foot and asks thepatient to raise the opposite leg. If the patient genuinelytries to raise the leg the examiner will feel pressureapplied to their hand. In a patient who is not sincere intheir effort, there will be no contralateral pressure tothe examining hand.

The reverse sciatic tension test may be useful in the



patient with a positive SLR test. This maneuver isperformed by plantar fl exing rather than dorsiflexingthe foot during the straight leg raise; if this results inincreased complaints of pain, the patient is not organic.

Differential Diagnosis Of Low Back Pain

The possible causes of low back pain are legion. (See Table 3 .) It is helpful for the emergency physician toconsider the worst first, despite the fact that mostpatients will have a benign cause. Low back pain in theelderly has a much wider range of possible causes thanin younger patients. Serious geriatric conditionsinclude certain malignancies, polymyalgia rheumatica,and aortic aneurysm. Many other pathologies, such asPagets disease, Parkinson disease, and osteoporosiswith compression fracture, occur almost exclusively inolder adults. 29

While malignancy is rarely an acute emergency,with the exception of epidural compression syn-dromes, it is an important diagnosable cause of backpain. One study of 1,975 outpatients with low backpain found that cancer could be excluded if noneof the following was present: age > 50, history of cancer, unexplained weight loss, and failure of conservative therapy. 11

Table 2. The Waddell Criteria.

Tenderness Superficial (significant pain to light touch or pinch) Non-anatomic (tender to palpation over LS, Pelvis, and TS)

Simulation Axial loading (low back pain with light pressure to skull

while standing) Rotation (increase of low back pain with passive rotation

of the shoulders and pelvis in the same plane, in thestanding position)

Distraction SLR: Inconsistent findings in sitting vs. supine straight leg

raising

Regional Disturbance Weakness: Generalized giving way or cog-wheeling

resistance when testing strength in the lower extremities Sensory: Stocking sensory loss, non-dermatomal

Overreaction (most important Waddell criteria) Disproportionate pain response Bracing: Both limbs supporting weight while seated Clutching, grasping affected area for more than three

seconds Dramatic grimacing Sighing with shoulders rising and falling

Annotations adapted from: Polatin PB, Cox B, Gatchel RJ, et al. Aprospective study of Waddell signs in patients with chronic low backpain: When they may not be predictive. Spine1997;22:1618-1621.

Table 3. How The Emergency Physician Considers The Differential Diagnosis Of Back Pain.

Immediate Threats To LifeAAAPulmonary embolism

(upper and mid-back generallynot lower back)

Thoracic aortic dissection(upper and mid-back

generally not lower back)Myocardial infarction(upper and mid-back generallynot lower back)

Immediate Threats ToSpinal CordEpidural mass effect

Tumor Hematoma Abscess Disc herniation (rarely

causes acute threat in

lumbar area)

Urgent ThreatsCardiac

EndocarditisRenal

Pyelonephritis Infected stone Renal artery dissection

Abdominal Perforated ulcer

Vertebral Unstable fracture

Gynecologic Abruptio placenta

Serious But Not Acutely DangerousVertebral

Osteomyelitis Pott s Disease (tubercu-

losis of spine) Tumor Stable fracture Spondylolisthesis

Disc Herniated Disc Discitis

Rheumatologic Ankylosing spondylitis

Abdominal Pancreatitis

Gynecologic PID

Less Serious (But MayRepresent A PainEmergency)Renal

Ureteral ColicGynecologic conditions

Pregnancy Endometriosis Ovarian conditions Dysmenorrhea

Musculoskeletal Lumbosacral strain

Varicella Zoster

Non-spinal ConditionsNon-spinal causes of back pain tend to be most lethal.Certainly AAA tops this list. It is the first diagnosis torule out by history, physical, or imaging studies in theolder patient with back pain. Some non-spinal infec-tions cause back pain, such as endocarditis and psoasabscess. More common and less serious causes of low

back pain involve renal condi tions such as pyelone-phritis and renal colic, as well as abdominal andpelvic pathology.

Spinal Causes Of Back Pain Table 4 (on page 6) outlines the spinal causes of backpain that are explained in the following sections.

Epidura l Compression Syndromes Epidural compression is a true emergency and should

be ruled out by history and physical examination inevery patient with back pain. While a completeepidural compression syndrome with paraplegia isobvious, mild or early compression can be difficult to

discern. However, the consequences of misdiagnosis



can be catastrophic, as most cases are progressive andoften irreversible. Diagnosing the early or subtle casesis made more difficult because MRI, the gold standardtest in making the diagnosis, can be difficult, if notimpossible, to obtain emergently.

Epidural compression syndrome is a collectiveterm encompassing spinal cord compression, caudaequina syndrome, and conus medullaris syndrome.Cauda equina syndrome differs from spinal cordcompression in that it occurs below the level of thecord and involves the spinal nerve roots of the caudaequina. Typically, patients present with a classicsyndrome of urinary retention with resultant inconti-nence, saddle anesthesia, anal sphincter laxity, andassociated bilateral weakness and sensory deficits inthe lower extremities. In the early stages, conusmedullaris syndrome commonly presents with bladderdysfunction and possibly fecal incontinence, with laterdevelopment of lower lumbar and sacral motor,sensory, and reflex impairment.

There are two reasons why these syndromes are

grouped together. First, individual syndromes arefrequently indistinguishable based on the presentinghistory and physical examination. For example, anincomplete spinal cord compressive lesion at T10 mayinitially present like a cauda equina syndrome. Sec-ondly, the initial ED evaluation and management forthese syndromes is similar.

Etiologies In the younger adult population, epidural compressionusually results from a cauda equina syndrome due to alarge central disc herniation. However, other etiologies toconsider in all age groups include primary or metastatic

tumors, epidural abscess, and trauma. Patients onwarfarin, or those with coagulopathy, may developspontaneous epidural hematomas or following trauma,including iatrogenic injury such as a lumbar puncture.

Presentation Some patients with epidural compression may presentwith a dramatic history, such as lower extremityweakness progressing to paraplegia in a matter of hours. Others have less sensational complaints of slowly progressive weakness or numbness. While backpain is frequent, it may not predominate.

The most important factors to consider are the bilaterali ty of the symptoms and the involvement of more than one spinal level. Lower extremity symptomsand signs may be associated with bowel or bladderincontinence and saddle anesthesia. Physical examinationusually reveals bilateral lower extremity weakness,hyporeflexia, and abnormal sensation. Often, there is nospecific nerve root distribution as multiple spinal levelsare involved, although one should attempt to determine a

spinal level. Urinary incontinence results from bladderspasms secondary to associated urinary retention.Urinary retention is approximately 90% sensitive for caudaequina syndrome, while decreased anal sphincter toneoccurs in 60-80% of cases. 21 Urinary retention or acomplaint of urinary incontinence is easily evaluated byobtaining a post-void residual through catheterization.Any residual volume greater than 50-100 mL is cause forconcern. Alternatively, ED ultrasonography may deter-mine post-void residual in a non-invasive manner.

Management When an emergency physician suspects an epidural

Table 4. Differential Diagnosis Of Spinal Etiologies For Back Pain.

Diagnosis Etiology/Findings Red FlagsLumbosacral strain (LSS) Ligamentous and muscular strain None

History of overuse or traumaWorse with activity, better with rest

Tenderness with lumbosacral palpation

Sciatica Herniated disk, most commonly at L4-L5 / L5-S1 YesLower extremity symptoms predominate (Neurologic complaints)Dermatomal distribution, radiates to foot (Neurologic deficits)Positive straight leg raise test

Spinal cord compression Large central disc herniation, tumor, trauma YesProgressive weakness in both lower extremities (Neurologic complaints)Mild back pain (Neurologic deficits)Emergent MRI indicated

Cauda equina syndr ome Similar etiology to spinal cord compression YesSaddle anesthesia (Neurologic complaints)Urinary retention, anal sphincter laxity (Neurologic deficits)Emergent MRI indicated

Spinal inf ection Prolonged symptoms (> 3 months) YesImmunocompromised, IDU (Fever, night sweats)S. au reus, S. epi derm id is, Str ept oco cci (Weight loss)urinary pathogens (Unrelenting pain)ESR is sensitive screen



compression syndrome, he or she must take quick action.Do not wait for a confirmatory MRI to begin treatment.Beginsteroids immediately, and call a neurosurgeon thedeficit is often progressive and potentially irreversible.

Epidural compression syndrome is one of the fewoccasions when an emergency physician should obtaina stat MRI. If MRI is not available, then CT withmyelography is the next best study.

Prognosis The prognosis of epidural compression syndromedepends upon the patient s neurological status at thetime of intervention. Specifically, for those patientswith epidural compression due to malignancy, thosewho are ambulatory generally remain so. Of patientswho are paraplegic at intervention, approximately 10%regain ambulation. 30,31

Spinal InfectionsInfection is an uncommon cause of back pain thatgenerally occurs in immunocompromised patients

(diabetics, injection drug users [IDUs], transplantpatients, and cancer patients). These patients typicallyhave prolonged symptoms, and in more than half of those with osteomyelitis, the pain has been present forthree or more months. 16,17,22,32

Pain is nearly a universal complaint in spinalinfections. The pain is often insidious, and becomesunrelenting and nocturnal. The most common spinalinfections include vertebral osteomyelitis andepidural abscess. Staphylococcus aureus is thepredominant pathogen, although S. epidermidis,Streptococci,and even urinary pathogens such asE. coli or Proteus occur. 12,13,15-17

The physical exam can be misleading in patientswith spinal infections. In vertebral osteomyelitis, feveroccurs in only half of patients; epidural abscess ismuch more likely to produce fever. 12,15-17,33 Mostpatients will have vertebral body percussion tender-ness, although this finding is nonspecific.

Lab testing can also be deceptive. The white bloodcell (WBC) count is elevated in fewer than 50% of patients with spinal infection. 12,13,15-17,34 However, theerythrocyte sedimentation rate (ESR) is a sensitive butnonspecific screening test, elevated in greater than 95%of patients with a normal immune system and 90% of those with immune suppression. 12,13,16,17,22

The emergency physician should order diagnosticimaging when they suspect spinal infection. Plain filmsmay be useful, but a spinal MRI (the gold standard) orCT is more sensitive and specific than radiographs.This is especially true early in the disease process, as itmay take up to eight weeks before lytic changes become evident on x-ray. 17,32

The prognosis for spinal infection is fair, withmortality rates ranging from less than 5% to greaterthan 25%. 12,15-17,32 The outcome depends upon the natureof the infection (osteomyelitis vs epidural abscess), thepatient s immune system status, and general health.

SciaticaSciatica is defined as pain in the distribution of alumbar or sacral nerve root, often accompanied bysensory or motor deficits. 2 True sciatica is much lesscommon than LSS, affecting approximately 1% of patients with acute low back pain. 2 The typical patientcomplains of mild to moderate back pain, but the keyto the diagnosis is radicular pain below the knee.Usually, this affects only one leg and is often associatedwith paresthesias, numbness, and possibly weaknesson the affected side.

The cause of sciatica is usually a herniated inter-vertebral disc; 95% of patients with herniated discspresent with sciatica as a chief complaint. 2 Otheretiologies to consider include foraminal stenosis, spinalstenosis, intraspinal tumor or infection, and piriformissyndrome. Piriformis syndrome is a lesser-knowncause of sciatica whereby trauma or injury to thepiriformis muscle results in spasm and inflammationthat may produce concomitant sciatic nerve impinge-ment. 2,35 In one study, it accounted for 6% of patients

with chronic back pain.36

Ninety-five percent of herniated discs occur at theL4-L5 or L5-S1 levels, which results in compression of the L5 or S1 nerve roots, respectively. This compressionproduces a radiculopathy along the dermatomes of theinvolved nerve root, as well as sensory, muscular, andreflex changes for the involved nerve root. 2 Patientswith L5 compression may have difficulty with heelwalking (and may demonstrate a foot drop), whilethose with an S1 problem may not be able to walk ontheir toes. Older patients have a higher incidence of more proximal disc herniation, such as L2-L3 and L3-L4.2 These patients may complain of pain in the

anterior thigh, and demonstrate sensory deficits in theL3 or L4 dermatomes as well as quadriceps weaknesswith an associated diminished patellar reflex. Thehistory may reveal some recent trauma; however, moreoften the patient complains of mild to moderate backpain that preceded the sciatica for a period of days toweeks. This back pain may or may not have improvedwith the appearance of the sciatica. 24 The pain of aherniated disc often worsens with Valsalva maneuvers,coughing, and sitting. 2,24

The physical examination of the patient withsciatica reveals a stationary patient. However, a majordifference between sciatica and LSS is the physicalexam findings. Namely, the straight leg raise test andthe lower extremity neurologic exam may be abnormalin patients with nerve root compression. Radiographicimaging for sciatica is generally not necessary in the EDbecause plain films will not demonstrate disc herniation.However, plain radiographs may be indicated if thereare red flags for malignancy, epidural compression,infection or fracture. 2,9,11,24,37,38 If the physician isconcerned about a more serious etiology for thesciatica, he or she may consider ordering an MRI or CTscan rather than plain radiography. However, this

Continued on page 15



Clinical Pathway: Evaluation Of PatientsWith Low Back Pain

Age >18 years non-pregnant acute (60 years old, consider AAA as first diagnosis to rule out(Class IIa)



Clinical Pathway: Evaluation Of PatientsWith Low Back Pain (continued)

No

Red flags for tumor: Age >50 or < 20 History of cancer Unexplained weight loss Duration of pain>1 month Persistent fever

Yes Consider ESR, CBC

and imaging studies(Class IIa)

(see also page 10)

Evidence of fracture or

serious disease?

Yes Appropriate treat-

ment or consultation(Class IIa)

No

Red flags for possible infection: IVDA Fever/chills Recent bacterial infection Immune suppression New heart murmur

Yes Consider ESR, CBC

and imaging studies(see page 10)

Evidence of fracture or

serious disease?

Yes Appropriate treat-ment or consultation

(Class IIa)

Red flags for cauda equinasyndrome:

Saddle anesthesia Recent onset of bladder/

bowel dysfunction (checkpost-void residual)

Severe or progressiveneurologic deficit in the

lower extremity Unexplained laxity of theanal sphincter

Major motor weakness of quadriceps or foot drop

Yes Go to page 10

No

Neurologic deficit: Motor and/or reflex changes Objective sensory loss

No

Yes Go to page 10

The evidence for recommendations is graded using the followingscale. For complete definitions, see back page. Class I: Definitelyrecommended. Definitive, excellent evidence provides support. ClassIIa: Acceptable and useful. Very good evidence provides support. ClassIIb: Acceptable and useful. Fair-to-good evidence provides support.Class III: Not acceptable, not useful, may be harmful. Indeterminate:

Continuing area of research.

This clinical pa thw ay is intended to supplement, rather tha n substitute, professional judgm ent an d m ay be chang ed depending upon a pat ient s individu al n eeds. Failure to comp ly with this pathw ay does not represent a breach of the standard of care.

Copyright 2000 Pinnacle Publishing, Inc. PinnaclePublishing (1-800-788-1900) grants permission toreproduce this Emergency Medicine Practice tool forinstitutional use.

No

Evidence of non-spinalmedical problems causingreferred back complaints?

No Provide assurance/education about back problems Activity as tolerated Review activity limitations Ibuprofen or acetaminophen Consider muscle relaxants, opioids(Class IIb)

Yes

Appropriate treat-ment or consultation

(Class IIa)

Special thanks to Dr. Andrew Asimos for this adaptation from theAHCPR guidelines.

Adapted from: Bigos S, Bowyer O, Braen, et al. Acute low backproblems in adults. Clinical Practice Guideline No. 14. AHCPRPublication No. 95-0642. Rockville, MD: Agency for Health Care Policyand Research, Public Health Service, U.S. Department of Health andHuman Services. December 1994. Agency for Health Care Adminis-

tration, State of Florida, in Consultation with the Medical/SurgicalNeuro-Musculo-Skeletal Guideline Committee and its NeurosurgicalSurgery Subcommitee: Universe of Florida Patients with Low BackPain or Injury. Medical Practice Guidelines for Practitioners LicensedUnder Chapter 458 (Medicine) or Chapter 459 (Osteopathy), FloridaStatutes, Florida Health Care Insurance Reform Act of 1993, Section4108.02; Florida Workers Compensation Reform Act of 1993, Section440.13(15). Endorsed October 6, 1995; amended February 2, 1996.

No



Clinical Pathway: Management Of Back PainAccording To Presumed Etiology

The evidence for recommendations is graded using the following scale. For complete definitions, see back page. Class I: Definitely recommended.Definitive, excellent evidence provides support. Class II a: Acceptable and useful. Very good evidence provides support. Class IIb: Acceptable and useful.Fair-to-good evidence provides support. Class III: Not acceptable, not useful, may be harmful. Indeterminate: Continuing area of research.

This clinical path way is intended to supplement, rather tha n substitute, professional jud gm ent and may b e changed depending up onpatient s individual needs. Failure to com ply w ith t his pathw ay does not represent a breach of th e stand ard of care.

Copyright 2000 Pinnacle Publishing, Inc. Pinnacle Publishing (1-800-788-1900) grants permission to reproduce thisEmergency Medicine Practice tool for institutional use.

Tumor? Age > 50 Night pain, unrelenting

pain Weight loss Pain > 6 weeks Fever

Spinal imaging (plainradiography or CT) (Class I)

ESR (Class IIa) CBC, UA C&S (Class IIb)

Consistent withtumor?

Specialty consultation(Class I)

No

No

Treat as lumbosacral strain;follow up with primary care

physician at 7-10 days (Class I)

See page 11 if history of cancer, fracture, sciatica, or

age < 18.

Yes

Yes

Infection? Fever, night sweats Night pain, unrelenting

pain Injection drug user Immunocompromised Pain > 6 weeks

CT or MRI (Class I) Plain radiography (Class IIb) CBC, ESR, UA C&S (Class I) Blood culture x 2 (Class IIa)

Consistent with

infection? Yes Admit/consult(Class I)

Consider antibioticsin ED (Class IIb)

No

Consider other etiology(ClassI)

No

Yes

Epidural compression? Saddle anesthesia Urinary retention Incontinence Neurological deficit

Dexamethasone (Class I) Emergent MRI (Class I)

Consult (Class I)

No

YesRed

flags?

Acutelumbosac-ral strain(Class I)

No

Yes



Clinical Pathway: Back Pain With Sciatica,Question of Fracture, Or Age Less Than 18 Years

No

Sciatica? Treat like HNP (Class IIa)or Consider plain radiography torule out tumor, fracture, spondylolis-

thesis, and infection (Class IIb)

Normal?

Yes

Treat like HNP (Class IIa)Follow up in 1-2 weeks with primary

care physician (Class IIa) Yes

No

Reevaluate (Indeterminate)

The evidence for recommendations is graded using the following scale. For complete definitions, see back page. Class I: Definitely recommended.Definitive, excellent evidence provides support. Class II a: Acceptable and useful. Very good evidence provides support. Class II b: Acceptable and useful.Fair-to-good evidence provides support. Class III: Not acceptable, not useful, may be harmful. Indeterminate: Continuing area of research.

This clinical path way is intended to supplement, rather tha n substitute, professional judg ment and may b e changed depending up onpatient s individual needs. Failure to com ply w ith t his pathw ay does not represent a breach of th e stand ard of care.


Fracture? History of trauma Age > 50 Osteoporosis

Plain radiography (Class IIa)

Normal?

Yes

Treat for acute lumbosacralstrain (Class IIa)

No

No

Treat for fracture type (Class IIa)Consult orthopedics (Class IIa)

Age less than 18 years? Plain films (Class IIa): two-view

initially; five-view if normal

CBC, ESR, UA (Class IIb)

Consistent withspondylolysis or

spondylolisthesis?

Yes

Treat for acute lumbosacralstrain (Class IIa)

Yes

No

Reevaluate (Indeterminate)

Yes



Clinical Pathway: Back Pain In The Cancer Patient

The evidence for recommendations is graded using the following scale. For complete definitions, see back page. Class I: Definitely recommended.Definitive, excellent evidence provides support. Class II a: Acceptable and useful. Very good evidence provides support. Class IIb: Acceptable and useful.Fair-to-good evidence provides support. Class III: Not acceptable, not useful, may be harmful. Indeterminate: Continuing area of research.

This clinical path way is intended to supplement, rather tha n substitute, professional jud gm ent and may b e changed depending up onpatient s individual needs. Failure to com ply w ith t his pathw ay does not represent a breach of th e stand ard of care.


History of cancer?

Group I:New or progressive

neurologic symptoms?

Treat like epidural compressionsyndrome (Class I)

Yes

Yes

No

Group II: Neurologicsymptoms, neither acute

nor progressivePlain radiography (Class I)

Yes

No X-rays consistentwith mets/tumor?

Yes Dexamethasone

(Class I) MRI < 24 hours

(Class I) No

MRI 3-5 days(Class IIb)

Close follow-up(Class I)

Plain radiography (Class I)

X-rays consistentwith mets/tumor?

YesConsult (Class I)

No

Treat like lumbosacralstrain (Class I)

Follow up with primarycare physician in one week(Class I)

Group III: Back pain only



AHCPR Tests For Low Back Pain

Adapted from: Bigos S, Bowyer O, Braen, et al. Acute low back problems in adults. Clinical Practice Guideline No. 14. AHCPR Publication No. 95-0642.Rockville, MD: Agency for Health Care Policy and Research, Public Health Service, U.S. Department of Health and Human Services. December 1994.Agency for Health Care Administration, State of Florida, in Consultation with the Medical/Surgical Neuro-Musculo-Skeletal Guideline Committee andits Neurosurgical Surgery Subcommitee: Universe of Florida Patients with Low Back Pain or Injury. Medical Practice Guidelines for PractitionersLicensed Under Chapter 458 (Medicine) or Chapter 459 (Osteopathy), Florida Statutes, Florida Health Care Insurance Reform Act of 1993, Section4108.02; Florida Workers Compensation Reform Act of 1993, Section 440.13(15). Endorsed October 6, 1995; amended February 2, 1996.

Testing for Lumbar Nerve Root Compromise

Nerve root L4 L5 S1

Pain

Great toe Heel

Numbness

Extension of Dorsiflexion Plantar flexionquadriceps of great toe of great toe

and foot and foot

Screening Squat Heel Walkingexam and rise walking on toes

Reflexes Knee jerk None Ankle jerkdiminished reliable diminished

Instructions For Sitting Knee Extension Test

With the patient sittingon a table, both hipand knees flexed at90 , slowly extend theknee as if evaluatingthe patella or bottom

of the foot. Thismaneuver stretchesnerve roots as much asa moderate degree of supine SLR.

Instructions For The Straight Leg Raise Test

1.Ask the patientto lie as straightas possible on atable in thesupine position.

2.With one handplaced abovethe knee of theleg beingexamined, exertenough firm pressure to keep the knee fully extended.Ask the patient to relax.

3.With the other hand cupped under the heel, slowly raisethe straight limb. Tell the patient, If this bothers you, letme know, and I will stop.

4.Monitor for any movement of the pelvis before com-plaints are elicited. True sciatic tension should elicitcomplaints before the hamstrings are stretched enoughto move the pelvis.

6.While holdingthe leg at thelimit of straightleg raising,dorsiflex theankle. Notewhether thisaggravates thepain. Internalrotation of the

5.Estimate the degree of leg elevation thatelicits complaint from the patient. Thendetermine the most distal area of discomfort: back, hip, thigh, knee, orbelow the knee.

limb can also increase the tension on the sciatic nerveroots.



AHCPRGuideline RecommendationsFor Assessment And Treatment Acute Low Back Problems in Adults

The ratings in parentheses indicate the scientific evidence supporting each recommendation according to the following scale:A = strong research-based evidence (multiple relevant and high-quality scientific studies)B = moderate research-based evidence (one relevant, high-quality scientific study or multiple adequate scientific studies)C = limited research-based evidence (at least one adequate scientific study in patients with low back pain)

D = panel interpretation of evidence not meeting inclusion criteria for research-based evidence The number of studies meeting panel review criteria is noted for each category.

History and physical exam (34 studies)

Recommend:Basic history ( B).History of cancer/infection ( B).Signs/symptoms of cauda equina syndrome ( C).History of significant trauma ( C).Psychosocial history ( C).Straight leg raising test ( B).Focused neurological exam ( B).

Option:

Pain drawing and visual analog scale ( D).

X-rays of L-S spine (18 studies)

Recommend:When red flags for fracture present ( C).When red flags for cancer or infection present ( C).

Recommend against:Routine use in first month of symptoms in absence of red flags ( B).Routine oblique views. ( B).

Imaging (18 studies)

Recommend:CT or MRI when cauda equina, tumor, infection, or fracture strongly

suspected ( C).MRI test of choice for patients with prior back surgery ( D).Assure quality criteria for imaging tests ( B).

Option:Myelography or CT-myelography for preoperative planning ( D).

Recommend against:Use of imaging test before one month in absence of red flags ( B).Discography or CT-discography ( C).

Medication (23 studies)

Recommend:Acetaminophen ( C).NSAIDs ( B).

Option:Muscle relaxants ( C).Opioids, short course ( C).

Recommend against:Opioids used >2 wks ( C).Phenylbutazone ( C).Oral steroids ( C).Colchicine ( B).Antidepressants ( C).

Adapted from: Bigos S, Bowyer O, Braen G. et al. Acute Low Back Problem s in Adults . Clinical Practice Guideline, Quick Reference Guide Number 14.Rockville, MD: U.S. Department of Health and Human Services, Public Health Service, Agency for Health Care Policy and Research, AHCPR Pub.No 95-0643. December 1994.

Physical treatment methods (42 studies)

Recommend:Manipulation of low back during first month of symptoms ( B).

Option:Manipulations for patients with radiculopathy ( C).Manipulation for patients with symptoms >1 month ( C).Self-application of heat or cold to low back ( C).Shoe insoles ( C).Corset for prevention in occupational setting ( C).

Recommend against:Manipulation for patients with undiagnosed neurologic

deficits ( D).Prolonged course of manipulation ( D).

Traction ( B). TENS ( C).Biofeedback ( C).Shoe lifts ( D).Corset for treatment ( D).

Injections (26 studies)

Option:Epidural steroid injections for radicular pain to avoid surgery ( C).

Recommend against:

Epidural injections for back pain without radiculopathy ( D). Trigger point injections ( C).Ligamentous injections ( C).Facet joint injections ( C).Needle acupuncture ( D).

Bed rest (4 studies)

Option:Bed rest of 2-4 days for severe radiculopathy ( D).

Recommend against:Bed rest >4 days ( B).

Activities and exercise (20 studies)

Recommend: Temporary avoidance of activities that increase mechanical stresson spine ( D).

Gradual return to normal activities ( B).Low-stress aerobic exercise ( C).Conditioning exercises for trunk muscles after 2 weeks ( C).Exercise quotas ( C).

Recommend against:Back-specific exercise machines ( D).

Therapeutic stretching of back muscles ( D).



approach has not been evaluated for cost-effectivenessand utility.

Acute Lumbosacral StrainThe majority of patients presenting with low back painsuffer from a benign condition commonly calledlumbosacral strain (LSS). This is an injury, possibly

with subsequent inflammation, of the lumbosacralligaments and musculature. The history and physicalexam are usually devoid of red flags. Often, thepatient relates a history of preceding trauma, such asheavy lifting; however, this is not universal, and manypatients cannot identify a specific preceding injury orepisode of overuse. The pain of LSS is well localized tothe lower back and upper buttocks, and typicallyworsens with activity and improves with rest. Physicalexamination reveals a patient lying supine and still,trying not to move. Often, tenderness over the paraver-tebral musculature is present, although exact reproduc-tion of the pain is atypical. As discussed later in this

article, no further diagnostic tests are required, andthese patients generally have an excellent prognosiswith conservative therapy. 2,9

Back pain is price man paid for the hubrisof walking erect.Anonymous

Diagnostic Studies

LaboratoryMost patients with low back pain do not need labora-tory testing in the ED. In selected patients, a few testsmay be helpful. These include a complete blood count

(CBC), a urinalysis (UA), and an erythrocyte sedimen-tation rate (ESR). These studies are indicated when thepatient has red flags for infection or tumor, or when achild presents with atraumatic back pain.

Blood TestsThe ESR is especially sensitive to spinalinfection. 12,13,15-17,22,34,39 In addition to non-spinalinfections (such as endocarditis), the ESR may also be elevated in the setting of neoplasm and rheum-atologic disease, such as ankylosing spondylitis. 11,40

While the CBC remains a reflex response to fever(despite the best efforts of Emergency Medicine Practice),it falls short in its performance in patients with spinalinfections. In most cases, it is falsely normal despitesignificant disease.

UrinalysisThe urinalysis may be useful in a variety of patientswith back pain, both acute and chronic. In the patientwith acute severe pain in the back or flank, a urinalysisis routine the assumption being that the presence orabsence of hematuria should direct evaluation of possible renal colic. However, recent data tends to

undermine the value of the urinalysis in this situation.In one study, 14% of patients with CT-proven ureteroli-thiasis had no hematuria on urine dipstick and 1 orless RBCs per high power field on microscopy. Of the

back-pain patients without ureterolithiasis whounderwent CT, 24% had more than 5 RBCs per highpower field. 41 Hematuria may be a prominent orincidental finding in many patients with non-renal

back pain, including those with AAA. At least onereport shows an 87% incidence of hematuria in rup-tured AAA (although most other reports are around30%).42 Furthermore, the presence of gross hematuriacauses a significant delay in the diagnosis because thephysician pursues a urinary work-up. 43 Still, the searchfor hematuria, whether by dipstick or microscope, willprobably continue to play a role in the evaluation of ureteral colic and acute back pain.

The urinalysis may also demonstrate signs of infection in patients with low back pain. This includesa positive leukocyte esterase reaction or positivenitrate on dipstick, and leukocytosis and bacteria or

both on microscopy. In young, otherwise healthywomen, pyelonephritis can cause back pain; it is veryrare in men who do not have prostatic hypertrophy ora prior history of renal disease. Women with pyelone-phritis usually complain of back pain in combinationwith fever and nausea, vomiting, or both. Pyuria isroutine. The combination of fever plus pyuria has a98% positive predictive value for pyelonephritis inadult women. In the afebrile woman with back painand pyuria, the emergency physician should considercompeting diagnoses in addition to pyelonephritis. 44

Based on the limited data, a urinalysis may be helpfulin women or in elderly patients of either sex who

present with a history of recent fever, nausea orvomiting, or with physical findings of elevatedtemperature or flank tenderness.

Obtaining a UA is also an important considerationin patients with chronic pain suspected of spinalinfection. A number of studies demonstrate that themost common primary source of infection in vertebralosteomyelitis is the genitourinary system, probablythrough hematogenous spread. 12,13,16,17,22,34 A urinalysisand urine culture may be helpful in identifying aspecific pathogen and ultimately tailoring antibiotics.

Radiographic StudiesPlain Radiograp hy Plain spinal radiographs are indicated whenever there ishistory of significant trauma, suspicion of fracture,infection, tumor, or neurologic deficit. Older patients andthose on chronic steroids may require x-rays after evenminor trauma, especially if they demonstrate percussiontenderness of the vertebrae. Plain films are limited intheir ability to detect infection, tumor, or herniated disc.It is unnecessary to obtain plain films in patients withonly back pain and no red flags. Because symptoms willresolve in approximately 90% of these patients within 4

Continued from page 7



to 6 weeks, a diagnostic work-up only adds cost andradiation exposure, without any impact on the casemanagement. Plain films cost between $170 and $200 perstudy and yield nearly 2,000 times the gonadal radiationas chest x-ray. (A chilling thought.)

When the decision is made to obtain plain radio-graphs, only AP and lateral views of the lumbar spineshould be obtained, as the oblique and cone-downviews typically add little information. 2,37,38 Also, thetwo-view lumbosacral series exposes the gonads toonly half of the radiation that the patient wouldotherwise be exposed to in the standard five-viewseries. 2,38 Because the two-view series costs about $120less than the five-view series, obtain the two-viewseries initially and review it before obtaining anyadditional views. Complete a five-view series if thereis an abnormality on the initial views. A five-viewseries is also useful in patients under age 18 if spondy-lolysis or spondylolisthesis is suspected but notidentified on the initial views.

M RI Any patient with signs or symptoms suggestive of epidural compression warrants an emergent MRI. TheMRI may initially be limited to the lumbosacral spinein patients with suspected cauda equina syndromesecondary to disc herniation, especially if back pain islocalized to the lower lumbar spine. However, theentire spine (cervical, thoracic, lumbar, and sacral)should be evaluated in patients with suspected spinalcord compression for two reasons. First, there is therisk of localizing the physical findings to the wrongspinal level and potentially missing a more proximallesion on the MRI. 45,46 Second, there is a 10% chance of

asymptomatic distant metastases in metastatic cordcompression, and their discovery may alter thetherapeutic plan. 30 In addition to diagnosing epiduralcompressive lesions, MRI is the gold standard test for

spinal infection, tumor, herniated disc, spinal he-matoma, and acute neurological deterioration, becauseit clearly delineates spinal cord, canal, and discanatomy. 12,32,34,46,47 Furthermore, MRI does not useionizing radiation. For this reason, it is the imagingstudy of choice in pregnant women. 47

Limita tions Of M RIs Limitations include availability, cost, time, claustro-phobia, contraindications, and over-sensitivity. MRI isnot available emergently, or at all, in many smallerhospitals. The average charge for an MRI with contrastof the lumbosacral spine is approximately $1,600,whereas a non-contrast CT scan of the same area costs$650 (plus a myelography fee, if used). Also, MRIrequires a significant amount of time depending on thenumber of spinal segments scanned. This may beextremely uncomfortable for the claustrophobic patientand frankly dangerous for the patient who is deterio-rating rapidly. MRI is contraindicated in individualswith pacemakers, intracardiac wires, some intracranial

aneurysm clips, and some types of heart valves.Finally, MRI is overly sensitive when used indiscrimi-nately. In one study, in patients with no history orsymptoms of back pain, MRI demonstrated discherniation or bulging in 22% of patients younger than60 years old and in 36% of those over age 60. 48 Mostauthorities do not consider isolated foot drop second-ary to a presumed herniated disc to be an indicationfor an acute MRI, since few surgeons would acutelyoperate on such a patient.

CT Scan The primary indication for CT scanning in the setting

of low back pain is fracture evaluation, since CT issuperior to MRI in evaluating bony architecture.However, when used in conjunction with myelography,CT scanning is as effective as MRI in diagnosing

Pearls And Pitfalls In Patients With Low Back Pain1. Always consider a rupturing abdominal aortic

aneurysm in patients over age 55 with acute lowback pain.

2. Patients with lumbosacral strain or sciatica should

continue their routine activities as tolerated rather thanundergoing bedrest.3. In the patient with low back pain and no red flags,

there s no need to obtain any diagnostic tests.4. Children with back pain have a higher incidence of

serious diagnosable etiologies for their symptoms andrequire diagnostic testing at the initial evaluation todetermine the etiology.

5. Discuss the need for antibiotics in the ED with the spinesurgeon before giving them in suspected cases of vertebral osteomyelitis.

6. Remember to obtain blood cultures and a urine culture

in the patient with a suspected spinal infection, as theyfrequently are positive.

7. Back pain in an injection drug user is an infection(osteomyelitis, endocarditis, or epidural abscess) until

proven otherwise.8. Patients with suspected herniated disc do not requireimaging with MRI unless they fail to improve in 4-6weeks; thus, there s no need to order this study out of the ED.

9. Only 5-10% of all patients with sciatica ultimatelyrequire surgery, so you do not need to refer them to aspine surgeon from the ED. Let their primary carephysician take care of specialty referral.

10. All patients with suspected epidural compressionsyndromes require treatment with steroids beforeobtaining confirming diagnostic tests.


17/24



ally used to treat low back pain include acetami-nophen, non-steroidal anti-inflammatory agents(NSAIDs), muscle relaxants, and opioid analgesics.

NSAIDs NSAIDs have long been the mainstay of pharmaco-therapy. Although randomized, placebo-controlledstudies of back pain are few, it is likely that most drugsof this class are equally effective. 50 The most commonside effects include gastrointestinal irritation anddeterioration of renal function. Because of these sideeffects, one may consider a trial of acetaminophenalone or in combination with an opioid or musclerelaxant in those at risk for NSAID complications.This at-risk population includes the elderly, thosewith prior GI bleeds, and patients with impairedrenal function.

Acetaminophen Not only does acetaminophen have fewer side effectsthan the NSAIDs, but it is less expensive. Acetami-

nophen has similar therapeutic effects as compared toNSAIDs for other musculoskeletal conditions, such asosteoarthritis. 51 If one suggests acetaminophen alone,consider a back-up regimen in case the acetaminophenis insufficient. The back-up prescription couldprevent a repeat visit to the ED or the primaryphysician s office.

Opioids If the pain is more severe, give narcotic analgesics inthe ED and prescribe them for home use. The durationis best limited to 1-2 weeks due to the risk of sedationand constipation. Caution the patient not to combine

acetaminophen with any acetaminophen-narcoticcombination medications.

Muscle relaxants such as diazepam, carisoprodol,and methocarbamol are also effective in treating acutelow back pain. Several studies have shown them to be better than placebo in the treatment of low back pain . 50

However, they are no more effective than NSAIDs inlow back pain, and they have no synergistic effectswhen used in combination with NSAIDs. 50 They are analternative therapy, especially in the patient at highrisk of side effects from NSAIDs.

Bed Rest Until the mid-1980s, patients with acute lumbosacralstrain were placed on seven days of strict bed rest.Subsequent research demonstrated that two days of bedrest were as effective as seven days. 52 Even more recentdata indicates that even two days of bed rest may beexcessive. Studies indicate that patients who resumenormal activities as tolerated by pain recover morerapidly than those placed at bed rest. 53 Back mobilizingexercises do not appear valuable in the acute setting.

Spinal Ma nipulation One especially controversial treatment option is

manipulation. The Agency for Health Care Policy andResearch (AHCPR) states that manipulation is safeand effective for patients in the first month of symp-toms [for lumbosacral sprain], but [has] unprovenefficacy after the first month. 9 However, recentresearch demonstrates that manipulation was no betterthan physical therapy. In terms of patient satisfactionat one and four weeks, manipulation proved onlyslightly better than a one-dollar educational bookletgiven at discharge. 54 A third study showed thatmanipulation was no better than standard medicaltherapy in terms of clinical outcome. 55

Other M odalit ies Numerous modalities, including spinal traction,massage, diathermy, ultrasound, biofeedback, transcu-taneous electrical nerve stimulation (TENS), acupunc-ture, and trigger point injections have been used totreat acute low back symptoms. These therapies haveno proven benefit in alleviating pain. 9 One mayeducate the patient on the use of heat or cold for

temporary symptom relief,9

but there are no good trialsto promote one modality over another.

Treatment Of Sciatica

The treatment of sciatica is similar to that of acutelumbosacral strain, but there are some exceptions.About 80% of patients with a herniated disc improvewith nonsurgical therapy, with only 5-10% ultimatelyrequiring surgery. 2,24,35 Conservative managementwith acetaminophen, NSAIDs, opioids, and/ormuscle relaxants is the best ED approach. As withlumbosacral strain, the patient with sciatica should

resume routine activity as tolerated by pain. Recentstudies show that early mobilization is more effectivethan bedrest. 56 Although proponents of manipulativetherapy do not consider sciatica as a contraindicationto manipulation, manipulation may cause or worsenneurological deficits. 2

While systemic corticosteroid therapy has noproven value for either sciatica or LSS, 50 epiduralsteroid injections may be indicated in some patientswith sciatica. While studies give conflictingresults, 12,57-59 one meta-analysis demonstrated a mar-ginal (10-15%) reduction in pain following epiduralsteroid injection vs. placebo in patients with sciatica. 50

Special Circumstances

Children and patients with a history of cancer arethe primary subsets of patients in whom seriousetiologies for back pain are most likely. The emergencyphysician should use extreme caution when evaluatingthese patients.

Back Pain In ChildrenTry to think of the last time that you evaluated a childwho suffered from atraumatic back pain. It may be



difficult to recall the case not because you have aweak mind, but because children rarely present to theED with this complaint. However, when it occurs, back pain in children is more l ikely to result f rom aserious etiology. 7,60

When taking the history, consider several factors.Has there been any change or increase in the patient sactivity level? Specifically, has the patient started anew exercise program, or is he or she participating ingymnastics, football, or dance? These activities raiseconcern for spondylolysis and spondylolisthesis. 60

Have there been any preceding bacterial or febrileillnesses? Bacteremia may predispose the patient to

spinal infections. Ask whether there been a change inthe child s gait, or any voluntary limitation of theiractivity because of the pain. Suspect serious pathologywhen children limit their activity because of the pain.Finally, nocturnal pain raises concern for either tumoror infection.

The physical examination is similar to that of theadult patient, with emphasis on several areas. Specifi-cally, examine the skin looking for bir thmarks suchas caf au lai t spots, which may indicate neurofibroma-tosis. Also, be alert for midline skin abnormalities onthe back, such as a hairy nevus, hemangioma, lipoma,or dermoid sinus. These midline lesions can signal an

Ten Excuses That Dont Work In Court1. Mr. Ancien had flank pain and microscopic hematuria.

That meant a kidney stone to me.Mr. Ancien arrested in the IVP suite. Patients with rupturingAAAs commonly present with back pain; many have

microscopic hematuria. Not surprisingly, renal colic is themost frequent incorrect diagnosis. Always consider AAAearly in patients who are over age 55 and complain of backpain. Helical CT (or in the hypotensive patient, a bedsideultrasound) are helpful if you suspect an abdominalaneurysm.

2. He was just a kid; children never have anything seriouslywrong with their backs.

This is almost true. Actually, children rarely complain of back pain, but when they do, it may be something serious,or at least diagnosable. In this case, it was cancer.

3. She only fell out of a chair. I dont x-ray every little old

lady who hurts herself when she falls. This case was eventually dropped, since one of theplaintiff s experts admitted that the film would not have ledto a major change in management. However, thecompression fracture caused her months of pain. Inaddition, she was angry about the little old lady wisecrack.

4. I thought he was drug-seeking. It was his third visit tothe ED in less than a week complaining of pain.

People with serious disease have serious pain. Unremittingpain despite standard management is worrisome fortumor or infection. Look for other red flags in the historyand physical.

5. I wasnt sure if she had normal rectal tone, but sheurinated 200 cc in the ED when asked.

This patient complained of back pain and trouble urinating,yet a post-void residual was never obtained. Urinaryretention is a red flag for cauda equina or conusmedullaris syndrome.

6. She had been seen by several other physicians over thepast few weeks for similar symptoms, so there could nothave been anything serious.

Beware of the patient who is seen several times in a shortperiod for back symptoms. There is a higher likelihood of

serious disease. A return visit may be a red flag forprogressive or missed pathology. As many as 20% of patients who return to the ED in 24 hours may requireemergency hospitalization. 62

7. He said he had the flu and complained of fever andback pain. I was going to give him IV fluids but he hadonly tracks for veins. I did give him a shot of Toradolbefore discharge. The plaintiff s attorney pointed out that ketorolac is a poorchoice for staphylococcal endocarditis. Fever is an ominouscomplaint in an IV drug user. 63 Fever and back pain suggestendocarditis in this group. In one large study, 7% of allpatients with endocarditis (whether IV drug users or not)had a chiefcomplaint of severe back pain. 64

8. Her radiographs were normal, so I figured she could nothave mets to her spine.

Beware the patient with a previous history of cancer andback pain. One-quarter of patients with neurologiccomplaints will have epidural metastases despite normalradiographs. Plain radiographs will miss early tumors ortumors within the spinal canal. If a patient with a history of cancer has neurological findings referable to the cord, theyneed an emergent MRI.

9. I am a careful doctorI waited for the results of the MRIbefore initiating steroid therapy. That s not careful, that s imprudent. Do not wait for theresults of the diagnostic tests in patients with suspectedepidural compression. The tests may not be completed for

several hours, during which time symptoms may worsen. If the patient ends up not having a compressive lesion, asingle dose of dexamethasone should not cause anysignificant problems.

10. But her cancer was diagnosed over 10 years ago.All patients with back pain and a history of cancer shouldhave plain radiographs of their back (unless they reterminally ill and require only comfort-care measures). Suchpatients have an increased risk of metastases. If theircomplaints are compatible with an epidural compressionsyndrome, see excuses 8 and 9.



underlying spina bifida or other spinal abnormalities.When examining the spine, note the amount of

thoracic kyphosis and lumbar lordosis, and test forscoliosis. Remember, however, that scoliosis alonerarely causes pain. Finally, observe the patient s gaitfor any abnormalities.

The initial diagnostic evaluation of the child with back pain should be more comprehensive than that of the adult patient. Almost every child who presentswith back pain should have anteroposterior and lateralradiographs of the involved spine. Oblique views may be included if the anteroposterior and lateral filmssuggest pathology. In addition to the radiographs,consider obtaining an ESR, UA (and possibly theunreliable CBC) depending upon a worrisome com-plaint, such as night pain, fever, or limitations of activity secondary to pain. If there is suspicion forinfection, tumor, or bony abnormalities, MRI or CTscan may be indicated.

The differential diagnosis of pediatric back paincan be classified according to age. (See Table 5 .) At age

10, problems of early childhood subside, and the newproblems of adolescence emerge. Adolescent patholo-gies continue until the age of 18, after which adult etiologies predominate.

Back Pain In The Patient With A History Of CancerPatients who have back pain and a history of cancerrepresent a unique group. They are at risk of spinalmetastases that can produce disastrous neurologicaldeterioration. These patients are best categorized intothree groups based on symptoms. 30

Group I: Patient s With New Or Progre ssive Signs

Of Neurological Compromise Group I consists of patients with new or progressiveevidence of epidural compression. Signs and symp-toms include new urinary urgency or incontinence,weakness, numbness, paresthesias, gait disturbances,absent reflexes, or the involvement of multiple or bilateral spinal levels. This group is at the highest riskof developing a complete epidural compressionsyndrome over hours to days and requires emergentintervention. (See related text.)

Group II: Patient s With Stab le Neurological Symp tom s Group II includes those patients with back pain andneurological symptoms present for several days toweeks. Findings are limited and may include anisolated Babinski s sign, or radicular pain, weakness,sensory or reflex changes in the distribution of a singlenerve root. The involvement of multiple nerve roots,multiple spinal levels, or bilateral symptoms placespatients into Group I.

Group II patients require plain spinal radiographyof the involved spine. If radiographs are consistentwith metastatic disease, epidural extension is presentin up to 88%. 46 These patients require 10 mg of intrave-nous dexamethasone and should undergo a spinal MRI

within 24 hours, if not emergently. The MRI can betargeted to the area of radiographic disease demon-strated by plain films. If the MRI demonstrates me-tastases, then the study should be expanded to includethe entire spine.

In those with normal radiographs, epidural meta-stases are still present in up to 25%. 46 In these patients,one may withhold dexamethasone therapy and arrangeurgent follow-up. MRI may be deferred for 3-5 days, aslong as the patient s symptoms remain stable .

Group III: Patient s With N o Neurolog ical Signs Or Symp tom s Group III includes those patients with back pain

but no neurological complaints or abnormalneurological findings. The emergency physicianshould evaluate these patients with plain spinalradiography. If normal, treat these patients conserva-tively with appropriate precautions and primary carefollow-up within 3-7 days. If abnormal, these patientsnecessitate consultation, as they will require a local-

ized spinal MRI. However, the MRI does not needto be obtained on an emergent basis, nor do thesepatients require dexamethasone.

Summary

No need to put the chart back in the rack! The emer-gency physician should view back pain as an impor-tant and manageable condition. The emergencyphysician may provide a rapid yet thorough evaluation

by focusing on the red flags of the history and physicalexam. These red flags will drive further diagnostictesting and eliminate immediate threats to life and to

the cord. Conservative treatment is the best approachto treating back pain, as symptoms resolve within 4-6weeks in the majority of patients. Be cautious in high-risk patients, such as the elderly, children, theimmunocompromised, and those with a history of cancer. Adherence to these principles (and a copy of

Table 5. Differential Diagnosis Of Back Pain InChildren By Age.

Age less than 10 diskitis tumor tuberculous osteomyelitis bacterial osteomyelitis congenital disorders

Age 10 and older spondylolysis spondylolisthesis Scheuermann s disease overuse syndrome tumor herniated disc vertebral osteomyelitis ankylosing spondylitis



the December 1999 issue of Emergency Medicine Practice,Pain Management In The ED: Prompt, Cost-Effective,State-of- the-Art Strategies ) will make back com-plaints a little less painful.

References

Evidence-based medicine requires a critical appraisal of theliterature based upon study methodology and number of subjects. Not all references are equally robust. The findingsof a large, prospective, randomized, and blinded trialshould carry more weight than a case report.

To help the reader judge the strength of eachreference, pertinent information about the study, suchas the type of study and the number of patients in thestudy, will be included in bold type following thereference, where available. In addition, the most

informative references cited in the paper, as deter-mined by the authors, will be noted by an asterisk (*)next to the number of the reference.

1. Elam KC, et al. How emergency physicians approach low back pain: Choosing costly options. J Emerg Med1995;13(2):143. (Physician survey; 283 questionnaires)

*2. Frymoyer J. Back pain and sciatica. N Engl J Med 1988;318:291-300. (Review)

3. Cypress BK. Characteristics of physician visits for backsymptoms: A national perspective. Am J Public Health1983;73:389-395. (Retrospective; 32 million visits forback pain)

4. Frymoyer J. An international challenge to the diagnosis andtreatment of disorders of the lumbar spine. Spine 1993;18:2147-2152. (Review)

5. van den Hoogen HM, Koes BW, van Eijk JT, et al. On theaccuracy of history, physical examination, and erythrocyte

Tool 1. Sample Discharge Instructions For Patients With Low Back Pain.

Copyright 2000 Pinnacle Publishing, Inc. Pinnacle Publishing (1-800-788-1900) grants permission to reproduce this

Emergency Medicine Practice tool for institutional use.

Activity:_____ Activity as tolerated (stop doing something if it hurts)_____ No lifting more than ______ lbs._____ Other: _________________________________________________________________________________

Sleeping: Rest on a firm mattress. If you get pain down your legs, sleeping on your side with your legs bent at the hips and

knees will help. If you sleep on your back, putting a fat pillow under your knees may help.

Come back to the Emergency Department immediately if you develop any of the following: Leaking urine or unable to urinate New numbness or weakness in your legs Inability to walk Inibility to control your bowels High fever

Medication:_____ You have been given a medication that may make you sleepy or drowsy.

Do not drive yourself home from the Emergency Department Do not drive a car or operate machinery within 12 hours of taking this medicine Do not drink alcohol while taking this medicine

Other Medicine:

_____ Take over-the-counter ibuprofen: _____tabs every ______ hours for _______days_____ Other: _________________________________________________________________________________

Follow-Up:_____ See your doctor in ____ days_____ Call ___________ for an appointment within ________days

Other Instructions:___________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Remember that the emergency department is open 24 hours a day, every day, and we are always glad tosee you.



sedimentation rate in diagnosing low back pain in generalpractice: A criteria-based review of the literature. Spine1995;20(3):318-327. (Review)

6. Roach KE, Brown M, Ricker E, et al. The use of patientsymptoms to screen for serious back problems. J Orthop SportsPhys Ther 1995;21(1):2-6. (Retrospective; 174 patients)

7. Micheli LJ, Wood R. Back pain in young athletes. Arch Pediatr Adolesc Med1995;149:15-18. (Retrospective; 200 patients)

8. Darke SG, Eadie D. Abdominal aortic aneurysmectomy: Areview of 60 consecutive cases contrasting elective andemergency surgery. J Cardiovasc Surg 1973;14:484-491. (Caseseries; 60 patients)

*9. Bigos S, Bowyer O, Braen G, et al. Acute low back problems inadults. Clinical Practice Guideline. Quick Reference GuideNumber 14. Rockville, MD: US Department of Health andHuman Services, Public Health Service, Agency for HealthCare Policy and Research, AHCPR Pub. No. 95-0643.December 1994. (AHCPR Consensus Guidelines)

10. Waddell G. A new clinical model for the treatment of lowback pain. Spine 1987;12:632-644. (Review)

*11. Deyo RA, Diehl AK. Cancer as a cause of back pain: Fre-quency, clinical presentation, and diagnostic strategies. J GenIntern Med 1988;3:230-238. (Prospective; 1,975 patients)

*12. Carragee EJ. Pyogenic vertebral osteomyelitis. J Bone Joint Surg

Am 1997;79:874-880. (Retrospective; 111 patients)13. Frederickson B, Yuan H, Olans R. Management and outcomeof pyogenic vertebral osteomyelitis. Clin Orthop 1978;131:160-167. (Case series; 17 patients)

14. Chandrasekar PH. Low-back pain and intravenous drugabusers. Arch Intern Med 1990;150:1125-1128.(Case series;14 patients)

15. Baker AS, Ojemann RG, Swartz MN, et al. Spinalepidural abscess. N Engl J Med 1975;293:463-468. (Caseseries; 39 patients)

16. Sapico FL, Montgomerie JZ. Pyogenic vertebral osteomyelitis:Report of nine cases and review of the literature. Rev Infect Dis1979;1:754-776. (Case series and literature review; 9 patients)

17. Ross PM, Fleming JL. Vertebral body osteomyelitis.Clin Orthop Res 1976;118:180-190. (Retrospective study;

37 patients)18. Kiev J, Eckhardt A, Kerstein MD. Reliability and accuracy of

physical examination in detection of abdominal aorticaneurysms. Vasc Surg 1997;31:143-146.

19. Marston WA, Ahlquist R, Johnson G Jr, et al. Misdiagnosis of ruptured abdominal aortic aneurysms. J Vasc Surg1992;16(1):17-22.

20. Lederle FA, Walker JM, Reinke DB. Selective screening forabdominal aortic aneurysms with physical examination andultrasound. Arch Intern Med 1988;148:1753-1756.

*21. Deyo R, Rainville J, Kent D. What can the history and physicalexamination tell us about low back pain? JAMA 1992;286:760-765. (Review)

22. Bonfiglio M, Lange TA, Kim YM. Pyogenic vertebralosteomyelitis. Clin Orthop Rel Res 1973;96:234-247. (Caseseries; 53 patients)

23. Basmajian JV, Burke MD, Burnett GW, et al. Stedm

back pain cost effective strategies for distinguishing between benign and life threatening causes

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