Low Back Pain Zacharia Isaac MD

Chief, Division of Spine Care and Pain Management Spaulding Rehabilitation Hospital

Pain is an Onerous Challenge

640 Billion $ per year

Number one cause of disability in people under 60

Epidemiology

• 26% of people have had low back pain lasting at least one day in the last 3 months

• 84% of people will have back pain at some point in their life

• Risk factors: obesity, smoking, age, female gender, physically strenuous work, sedentary work, psychologically strenuous work, job dissatisfaction, low educational attainment, workers compensation insurance, anxiety, depression

Etiologies

• Nonspecific Low back Pain : >85 % absence of reliably identified structure – just musculoskeletal “stuff”

• Vertebral Compression fractures: 4% of patients presenting to primary care docs. Age and chronic steroid use, prior fracture history

• Radiculopathy or Spinal Stenosis: 3-4 % • Ankylosing Spondylitis : 0.5%

Etiologies

• Serious stuff : less than 1% have things like • Cauda equina (compression of the spinal nerve root

cluster shaped like a horses tail called the cauda equina usually related to herniated disc or severe spinal stenosis or infection/ tumor : low back and bilateral leg pain with saddle anesthesia, motor weakness/ sensory changes, low anal sphincter tone, urinary retention/ incontinence )

Etiologies

• Serious stuff : less than 1% have things like • Metastatic Cancer : Breast, prostate, lung, thyroid,

kidney, myeloma • Epidural Abscess : fever, malaise, back/ radicular

pain • Vertebral Osteomyelitis :hematogenous spread of

bacteria post procedural

Painful structures

• Intervertebral disc

• Dorsal Ganglia of spinal nerve

• Facet Joint

• Ligaments

• Muscles

• Vascular perineural phenomenon

Pain is a Global experience

Meaning behind the pain - Is it cancer? Will it get worse? Am I falling apart ? What will I be like in 10 years?

Context and Impact - Will I lose my job ? Will I be able to play my sport? Will I be able to provide for my family

Emotions - the above add to the emotional panic, anxiety or depression occurring

Poor Correlation Between Function/Pain and Anatomy

unable to exercise or work Triathlete pain once/ per year

Poor Correlation Between Function/Pain and Anatomy

Unable to grocery shop Plays golf and walks dog

Why the disconnect between anatomy and pain/ function ?

Anatomical = herniated discs, spinal stenosis, facet arthritis

Biochemical = inflammation in periphery and CNS

Biomechanical = poor posture, deconditioned / tight muscles, demand

Neurological = modulation of signals in spinal cord, brain

Emotional = perception of the problem, fear

Pain/ Function

PAIN

versus

A time-based definition

Acute Pain/ Subacute ● Time limited, <4 to 12 weeks

● Results from injury to tissue

● Resolves with healing

● Example: herniated disc

Chronic Pain ● ≥3 months ● Continues after initial

injury heals ● Example: chronic low

back pain, fibromyalgia

● Less likely to improve

Mechanisms of pain

Neuropathic Pain Involves nervous system structures Pain is not associated with tissue damage, just hypersensitive

Nociceptive Pain

Pain is associated with tissue damage

Neuropathic Pain

Peripheral Mechanisms

● Bradykinins, PG, histamine, cytokines, nerve growth factors

● Membrane hyperexcitability ● Ectopic discharges ● Peripheral sensitization

Central Mechanism ● Central sensitization ● Central reorganization

of Aβ fibers ● Glial Cells ● Loss of inhibitory controls ● Emotions/ context ● Wind up

Rea Rodriguez-Raecke, et al PLoS One. 2013; 8(2): e54475.

Changes to Brain Occur in Chronic Hip OA

Biochemistry and Disc Degeneration

History • Need to define the nature of the inciting event, and time

relationship to onset of symptoms

• Axial or extremity symptoms ?

• Axial is lumbosacral junction

• Extremity is the thigh and beyond

• The buttock is a subjective clinical judgement but usually gets lumped with the predominating complaint

History • Assess Pain Intensity

• Assess function

• Work status, ADL, IADL (chores/ driving)

• Assess psychological function

• Symptom exaggeration

• Anxiety/ Depression/ panic

• Job satisfaction

Physical Examination

Physical Examination • Manual Muscle Testing and reflex testing

• Sensory Testing

• Provocative Maneuvers

• Spinal Nerve Root Tension

• Psychological Pain Behavior

• Test Hip, knee, shoulder and for upper motor neuron signs

Dermatomes

• Not fully explanatory of clinical presentation

• Autonomic Disturbances

• Sensory changes discordant

Pain referral pattern

• L5 Radiculopathy

Pain referral pattern

• S1 Radiculopathy

Pain referral pattern

• L4 radiculopathy

Spinal Nerve Root Tension

• Herniated discs generate inflammatory cascade

• Tethering of spinal nerve root and dura

• Straight Leg Raise – L5 and S1

• Femoral Stretch – L2,L3,L4

• Sitting root sign, Slump test

Examination features in Spinal Stenosis

• Usually negative straight leg raise

• No clear myotomal deficit

• Distal symmetric loss of vibratory sensation

• Sustained extension of the spine elicits back/extremity symptoms

• Gait is forward stooped

Mechanical Low Back Pain

• Discogenic Pain

• Facet Joint

• Sacroiliac Joint Syndrome

• Myofascial Pain

Facet Syndrome • Axial pain, exacerbated with standing and

walking

• referred pain to extremity without neural compression

• MRI findings can demonstrate nonspecific findings of facet arthropathy

• diagnosis made with controlled diagnostic anesthetization of the facet joint or its innervation

Facet osteoarthropathy

Facet Pain • Facet injections/ radiofrequency ablation

Facet Pain Referral

Facet Syndrome

• Intra-articular steroid injection

• Usually the L4-5 and L5-S1 Joints, Maybe L3-4

• More evidence for Radiofrequency ablation

• Must undergo 2 diagnostic anesthetizations of the medial branch nerves (usually L3, L4, L5 MBB) with ideally greater than 50-80% reduction in pain for 1-2 hours

Sacroiliac Joint Syndrome • Not sacroiliitis

• Need to consider radicular pain, discogenic pain, facet pain first

• Double block to define diagnosis (intra-articular versus Lateral Branch Nerves)

• Intra-articular steroid and physical therapy

• Role of Denervation Of Lateral Branch Nerves

SI Joint Syndrome

• Back and buttock pain which can refer to the extremity

• Often seen post trauma, intra or post partum, or without inciting etiology

• Not associated with specific radiographic features

SI Joint Syndrome • More than 2 provocative exam maneuvers

correlates with positive diagnostic block (Broadhurst, Laslett, Slipman)

• Symptoms in back, buttock, groin, thigh

• If symptoms above the L5 transverse process or In Ischium, less likely

Discogenic Pain

• Disc receives innervation from: Sinuvertebral nerve (ventral Ramus), Vertebral Nerve (autonomic root from sympathetic nervous system) and collateralize with ventral rami (somatic afferent)

• Pain Referral Patterns Reproducible and follow an anatomic trend

Bogduk et al. Spine 1988; 13(1):2-8 Slipman et al, The Spine Journal 2005; 5:381-388

Discogenic Pain

Diagnostic Testing • X-rays/ MRI/ CT/ Myelography

• Electromyography

• Diagnostic anesthetization

• Spinal Nerve Root

• Hip

• Facet joint/ Medial Branch Blocks

• Sacroiliac joint

Xrays • Useful for fractures, spondylolisthesis, segmental

instability

CT and MRI • Identify herniated disc, spinal stenosis,

degenerative disc disease

• Evaluate for tumor, infection, fracture

• CT – radiation exposure, $$

• MRI – no radiation exposure, $$$. Cost decreasing

Asymptomatic Findings on MRI - boden 1990

Electromyography ● Electromyography

○ Needle exam identifies spinal nerve

root motor involvement

○ Insensitive to clinical syndrome of

radicular pain

○ Good for diagnosing some peripheral

neuropathies and peripheral

entrapments

Treatment of Back Pain

Treatment • Targets of treatment

• Biomechanics: Core strength, Activity level, surgical

• Local inflammation : Corticosteroid injections, Nsaids, Motion

• Centrally Mediated Pain

• Desensitize: meds, exercise, CBT, MBSR

• Comorbidities – tobacco, obesity, mood, sleep

Reassure your patients

• Borenstein 2001

• Asymptomatic patients with MRI abnormalities followed for 7 years

• 58% did not develop back pain

• No correlation between severity of abnormality and symptoms

Treatment for Acute Low Back Pain

• General Approach – prioritize safety, cost, patient preference, education and reassurance

• Nonsuperiority of all treatments • Early return to activity and minimize bed rest • Return to work with modifications

Treatment of Acute Low Back Pain

• Physical therapy if kinesiophobia and needs encouragement or if psychiatric comorbidities

• Manual therapy + exercise • Nsaids, acetaminophen, muscle relaxants • Opioids confer no additional benefit than nsaid

(Friedman et al Jama 2015) • No evidence for oral steroids, spinal injections,

antidepressants, antiepileptics in acute LBP • Prognosis not that rosy – although 80% improve, 50%

recurrence of low back pain in 6 months and 70% in 1 year, 5-10% go on to chronic pain

Prevention

• Exercise and ? Weight loss • No clear evidence to support lumbar braces, mattresses, herbal therapies, tobacco cessation

Chronic Low Back Pain

• Predictors of developing chronic low back pain: • Functional impairment • Maladaptive coping behaviors (fear/ activity

avoidance/ catastrophizing) • Psychiatric comorbidities • Nonorganic signs

Treatment of Chronic Low Back Pain

• Emphasize active therapies • Movement • Physical therapy • Yoga, Tai chi • CBT/ MBSR, biofeedback, progressive relaxation,

multidisciplinary rehabilitation

Treatment of Chronic Low Back Pain

• Passive treatments adjuctively • Acupuncture • Spinal manipulation • Specialty referral regarding the role of : • Medications • Injections • Surgery

Medication Treatment of Chronic Low Back Pain

• Nsaids and muscle relaxants for ups and downs • Tramadol and Duloxetine for second line • Avoid opioids – more side effects and less efficacy in

patients with psychiatric comorbidities • ? Anticonvulsants such as gabapentin

Epidural Steroid Injections

• More helpful for radicular pain short term(HNP)

• Transforaminal/ Selective Nerve Root Block

• Interlaminar/ Translaminar/ Paralaminar

• Caudal

Transforaminal Injection

Caudal ESI

Interlaminar Epidural Steroid Injection

Key Points

• Screen for Red Flags • Imaging for chronic and persistent back and/ or radicular

pain • Focus on patient function, and resumption of normal

activity, and patient centered goals

Lifestyle Change

Next Steps

• Focus on wellness and general health prioritizing ideal

body weight, regular exercise, tobacco cessation, treatment of anxiety/ depression, mitigation of neurotic thought processes regarding pain, mindfulness/ meditation/ cognitive behavioral therapy

• Specialist referral

Motivational Interviewing

• Most of us went into our profession because of our eagerness to help, to “fix” circumstances or people who are “broken”

• When we identify “broken” circumstances or people we often jump in with advice, and direction

• This innate reflex was strengthened by our professional training

• When practicing MI we must resist this reflex and have the patient outline the strategies for change