Evaluation of Acute Low Back Pain An Evidence-Based Approach Harlan R. Ribnik, M.D., F.I.P.P. Diplomate, American Board of Anesthesiology Subspecialty Certified in Pain Medicine Diplomate, American Board of Interventional Pain Physicians

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What is Pain? The International Association for the Study of Pain says it is

"an unpleasant sensory and emotional experience in association with actual or potential tissue damage, or described in terms of such damage."

Is it Back Pain?  

Lumbar Spinal Pain –  Is perceived as arising anywhere within a region bounded superiorly by an imaginary transverse line through the tip of the last thoracic spinous process, inferiorly by an imaginary transverse line through the tip of the first sacral spinous process, and laterally by vertical lines tangential the lateral borders of the lumbar erectores spinae.

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Is it Back Pain?  

Sacral Spinal Pain –  Is perceived as arising anywhere within a region bounded superiorly by an imaginary transverse line through the tip of the first sacral spinous process, inferiorly by an imaginary transverse line through the posterior sacrococcygeal joints and laterally by imaginary lines passing through the posterior superior and posterior inferior iliac spines.

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Is it Back Pain?  

Lumbosacral Pain –  Is perceived as arising from a region encompassing or centered over the lower third of the lumbar region, as described above, and the upper third of the sacral region as described above.

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Is It Back Pain?

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Pain Acuity  

Acute –  Present < 3 months

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Subacute –  5-7 weeks up to 12 weeks

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Chronic –  Present at least 3 months

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Referred Pain  

Pain perceived in a region innervated by nerves other than the ones that innervate the actual source of the pain. –  Visceral Referred Pain. e.g. uterus, abdominal aorta, pancreatitis. –  Somatic Referred Pain. e.g. Z-joints, Discs, S-I joint

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Referred Pain

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Referred vs. Radicular Pain   Somatic

Radicular Pain

Pain

–  Can be referred distal to knee –  Deep, dull ache –  Distributed in wide areas –  Tends to stay in same location, may wax and wane

Shooting, lancinating, electrical Distributed in a narrow band Travels into lower limb

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Natural History  

UK, Netherlands, USA –  Patients are likely to recover –  Median time to recover = 7 weeks –  Relapses are common –  Status of patient at 2 months indicative of that at 12 months –  Up to 80% disabled to some degree (10-15% severely) –  Lost to follow-up, probably not recovered Pain Consultants of the Rockies, PC

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Natural History   Australia

–  Up to 70% can expect to recover and remain so at 12 months. –  Lower risk of recurrence. –  (Study excluded Workers Compensation)

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Prognostic Risk Factors    

Predict Chronicity. Biologic and Psychosocial Factors Biologic Factors – immutable and remediable. –  Age, gender, race –  Fractures, infections, e.g. –  Muscle weakness, immobility, lack of fitness

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Psychosocial Factors – immutable and remediable –  Personality type, Hx Psych distress. –  Socioeconomic status, intelligence, job dissatisfaction, education –  Beliefs, cognitions, fears Pain Consultants of the Rockies, PC

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Prognostic Risk Factors for Chronic Back Pain

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Predictors of Chronicity  

Cardinal Risk Factors –  Hx low back pain –  Dissatisfaction with current job –  Widespread Pain –  Radiating leg pain –  Restriction in 2 or more spinal movements –  gender

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Predictors of Chronicity  

Percentages of Patients who Become Chronic Based on Number of Cardinal Risk Factors: –  0-2 – 6% –  3-4 – 27-35% –  5-6 - 70%

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History  

Is it really Back Pain?

Chief Complaint

 

Length of Illness   Site of Pain   Location and Extent of Spread

Establish Acuity Record Primary site Referred vs. Radicular

Quality   Severity   Frequency

Somatic vs. Radicular

 

Baseline pain score Not of Dx value Pain Consultants of the Rockies, PC

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History  

Not of Dx value

Duration

Time of Onset   Mode of Onset   Precipitating Factors   Aggravating Factors   Relieving Factors   Associated Features  

Beware Night Pain! Beware Sudden Severe! Not of Dx value Absent Mech Aggravations

Not of Dx value Source of most signif Dx features

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History – Red Flag Conditions  

Fractures, Infections, Tumors –  Rare –  Hx and P.E. –  Special Tests may miss these early on

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History – Red Flag Conditions  

Cancer –  Past Hx Cancer –  Age > 50 –  Prolonged illness –  Failure to improve with treatment –  Unexplained weight loss

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History – Red Flag Conditions  

Fractures –  Major trauma –  Minor trauma in •  Age > 50 •  Osteoporosis •  Corticosteroids

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History – Red Flag Conditions  

Spinal Infection –  Fever –  History of body penetration –  Diabetes mellitus

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History – Red Flag Conditions Consider MRI imaging if the patient has the Alerting Features for Cancer or an ESR > 50

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Physical Examination “Although this process may be conventional and whereas it serves to provide a description of the patient, the existing evidence base shows that no particular clinical sign, or combination of signs, found by this process, allows a valid or reliable diagnosis of back pain to be made in anatomical or pathological terms.” - Bogduk N, McGuirk B. Chapter 7, Physical Examination. Medical Management of Acute and Chronic Low Back Pain, An Evidence-Based Approach Pain Research and Clinical Management, Vol. 13 2002 Elsevier Science B.V.

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Physical Examination  

Inspection –  Reliable for identifying structural anomalies –  No bearing on Dx of cause of low back pain

 

Palpation –  Reproduction of pain lacks reliability and validity

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Range of Motion –  Limitations or guarding do not imply any specific Dx

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Physical Examination  

Intervertebral Motion –  Poor agreements on estimates of intersegmental motion

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McKenzie –  Reliability varies –  Marginally effective as a diagnostic test

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Sacroiliac Joint –  Testing lacks validity, 25% false positives!

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Physical Examination  

Normal Examination –  In the face of spinal pain, should alert examiner to possible Red Flag Conditions

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Physical Examination  

Neurologic Examination –  Back Pain only •  No neuro Sx –  Somatic Referred Pain •  If in doubt, do the exam

–  Radicular Pain •  Do Neuro exam –  Neurological Symptoms •  Exam mandatory Pain Consultants of the Rockies, PC

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Radiographic Examination  

Plain Film Indications –  Age > 50 –  Significant trauma –  Neurological deficit –  Weight loss –  Suspect ankylosing spondylitis –  Drug or alcohol abuse –  History cancer –  Corticosteroid use –  Temp > 37.8C –  No improvement in 1 month –  Seeking compensation

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Radiographic Examination  

CT Scan

–  No place in investigation of low back pain of unknown origin  

MRI Scan –  Expensive, may reveal HNP –  Not for acute LBP

 

Bone Scan –  Suspected infection –  Incipient Fx pars interarticularis

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Algorithm  

Pain Consultants of the Rockies, PC

For management of Acute Low Back Pain

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Questions?  

Contact us at –  Harlan Ribnik, M.D. Pain Consultants of the Rockies, PC 307-633-8100 307-633-8108 (fax) –  4136 Laramie St Cheyenne, WY 82001

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Questions?  

Contact us at –  Harlan Ribnik, M.D. Pain Consultants of the Rockies, PC 307-633-8100 307-633-8108 (fax) –  4136 Laramie St Cheyenne, WY 82001

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