Low Back Pain

Elizabeth Chang, MDPGY-2

46 yo male p/w LBP x 6 mo

- Started 6 mo. ago while lifting boxes at his delivery job- Located middle of lower back, radiates to right buttock

and right lateral aspect of right foot- Pain worsened with sneezing/coughing- Difficult to stand on tip toes- Absent right ankle jerk- Straight leg test, cannot elevate right leg above 35

degrees- No urinary/bowel incontinence, fevers, weight loss- Otherwise healthy

“Fun” Facts

• #2 reason patients show up in your office• 84% of adults in US have LBP at some point• Up to 85% no definitive cause found• Costs the economy $100 BILLION per year• Substantial impact on lifestyle and quality of

life• <5% have serious systemic pathology

Differential for LBP

Red Flags

• History of cancer• Age > 50• Unexplained weight loss• Symptoms of neurological compromise• Pain lasting >3 mo.• Nighttime pain• Unresponsiveness to previous therapies• History of AAA• Risk factors for spinal infection (HIV, IVDA, etc)

Radiological/Anatomic

Spondylosis: arthritis of the spine – disc space narrowing, arthritic changes in joint facet

Spondylolisthesis: anterior displacement of a vertebra on the one beneath it. Graded I – IV

Sponylolysis: fracture in the pars interarticularis that protects the nerve

Spinal stenosis: narrowing of the central spinal canal (bony enlargement or thickened ligamentum flavum). Shopping cart sign.

Ankylosing Spondylitis

• Chronic inflammatory disease of axial skeleton• Sacroiliac joint involvement, bamboo spine on

imaging• Males, 20-30s, HLA-B27• Dull vague stiffness, slowly progressive over

years, worse at night, better with light activity• Elevated ESR, CRP• No cure, conservative management

Physical

Lumbar lordosis – inward curveKyphosis – outward curveScoliosis – sideways curve (always abnormal)

Neurologic

• Sciatica– set of symptoms, not a dx– compression/irritation of one

of the 5 spinal roots– affects posterior/lateral

aspect of leg to the foot/ankle

Radiculopathy – impairment of nerve root causing radiating pain, numbness/tingling, muscle weakness corresponding to specific nerve root. Most often herniated disc. Worsened with bending over.

Cauda Equina Syndrome

• Saddle anesthesia• Recent onset bladder dysfunction• Severe or progressive neurologic deficit in

lower extremity

Surgery

Classifications

• Acute: <4 weeks– Excellent prognosis, 90% full recovery

• Subacute: 4-12 weeks

• Chronic: >12 weeks

The Physical Exam 1

The Physical Exam 2

• Reflexes– Achilles tests S1 nerve root– Patellar tests L4– Upgoing toes may indicate upper motor neuron instead

• Straight Leg Test (for sciatic nerve irritation)– Pain below knee at <70 degrees worsened by ankle dorsiflexion

suggests L5/S1 tension from disc herniation

• Sitting Knee Extension Test– Should reproduce any findings from the SLT, helps clinician

discover inconsistent findings

Non-pharmacological treatments

• Exercise/PT/OT– Proven modest benefits in subacute/chronic LBP– Yoga, pilates, tai chi

• Spinal manipulation– Serious adverse effects rare (<1/1,000,000)

• Acupuncture• Massage• TENS (transcutaneous electrical nerve stimulation) –

large study showed no difference

1st Line Pharmacotherapy

• NSAIDS – Ibuprofen 400-600 mg QID or Naproxen 220-550

mg BID or IM ketoralac 60 mg (ER)– Caution in elderly, nephrotoxic, GI

• Acetaminophen as alternative– Max 4g/day– Hepatotoxicity risk

Centrally-acting skeletal muscle relaxants

• Limit use to 3 weeks• Anti-cholinergic side effects– Cyclobenzaprine– Methocarbamol– Carisoprodol

• Baclofen• Benzos – less evidence supporting efficacy,

high risk abuse

Opioids

• Norco, percocet, MS Contin• Tramadol – non-opioid that acts on opioid

receptors• Sedation, confusion, nausea, constipation,

respiratory depression in high doses• Misuse and abuse (30-45%) – scheduled

rather than prn• Short-term only

Anti-depressants & Anti-epileptics

• Tricyclics (amitriptyline)– Drowsiness, dry mouth, dizziness

• Radiculopathic pain– Gabapentin, pregabalin, topiramate

Glucocorticoids

• Limited data on efficacy and safety• Not recommended

The End