Backache is second only to common cold as a cause of days of sickness. 80-90% adults will have backache at some point in their lives. Most prevalent age is between 30 to 50 years. No specific diagnosis can be made in 80% cases and is common cause of disability for persons greater than 45 years of age. 80-90% improve within 4 weeks.
Causes of Backache
Lumbar “strain” or “sprain” – 70%
Degenerative changes – 10%
Herniated disk – 4%
Osteoporosis compression fractures – 4%
Spinal stenosis – 3%
Spondylolisthesis – 2%
Spondylolysis, discogenic low back pain or other instability – 2%
Traumatic fracture – <1%
Congenital disease – <1%
Cancer – 0.7%
Inflammatory arthritis – 0.3%
Infections – 0.01%
Nerve Root Pain
Nerve root pain occurs due to nerve root irritation e.g from a prolapsed disc. Shooting pain and paraesthesia down back of thigh sometimes as far as the heel may be found. It may also affect anterolateral thigh if femoral nerve roots are affected.
Benign Mechanical Backache
Benign mechanical backache is usually worse in the morning, then improves with activity, and varies with posture/activity. It is usually lower lumbar pain, also buttocks and thighs may be affected and is dull poorly localized pain. Cause cannot be attributed to any specific pathology.
To distinguish between benign mechanical back pain and sinister causes of back pain. 95% will be due to mechanical back pain, less than 5% nerve root irritation from disc prolapse and less than 1% will have more sinister pathology.
Cancer or Infection
- Age > 50yrs
- History of Cancer
- Unexplained weight loss
- Immuno suppression
- UTI, IV Drug abuse, Fever or chills
- Backache not improved with rest
- History of Significant Trauma
- Prolonged use of Steroids
- Age > 70yrs
Cauda Equina Syndrome or Severe Neurological Compromise
- Acute onset of urinary retention or overflow incontinence
- Fecal incontinence or loss of anal tone
- Saddle anaesthesia
- Global or progressive weakness in LE
Inspection is ideally done with back and legs exposed.Posture must be noted. Is there any scoliosis or kyphosis?
Skin café-au-lait spots, hairy patches, signs of psoriasis must be observed. Prolapsed disc may cause a lumbar scoliosis, flattening or reversal of normal lumbar lordosis.
Check for bone tenderness – this may indicate serious pathology e.g infection, fracture, malignancy. With patient leaning forwards check for tenderness between the vertebral spines and paraspinal muscles. e.g prolapsed disc, mechanical back pain. Palpable steps may indicate spondylolisthesis.
Ask patient to bend forward. Lightly percuss spine from neck to sacrum. Significant pain is a feature of infections fractures and neoplasms. Beware exaggerated response may be a non organic problem.
Flexion <5cm = abnormal – schobers test
Extension – pain and restricted extension in prolapsed disc and spondylolisthesis
Rotation – seated, movement is thoracic
L1/L2 – Hip flexion
L3/L4 – Knee extension
L4 – Ankle dorsiflexion
L5 – Great toe extension
S1 – Eversion
S2 – Knee flexion
Look for red flags and disc lesions persisting beyond 6 weeks in which surgery is considered.
Plain Lumbosacral X-rays
Unexpected finding may be present in 1:2500 adults. Evidence of degenerative changes as frequent in symptomatic as in asymptomatic. Red flags serve as the starting point.
Supplanted CT and myelography as initial diagnostic test. No radiation exposure occurs but does not visualize bone well.
CT scan images soft tissue to a degree that may be adequate. Excellent bony detail is present, and is faster being less expensive.
Sensitivity and specificity is similar to CT scan. It is an invasive test requiring hospitalization.
Discography, Bone scan or electromyelography (EMG) may also be considered.
Conservative treatment includes activity modification, bed rest, exercise, analgesics, steroids, antidepressants, muscle relaxants, epidural injections and physical treatments.
Surgery may be considered:
- In patients with less than 4-8 weeks of symptoms if red flags are present e.g Cauda equina syndrome, progressive neurologic deficit or profound motor weakness. Surgery may also be considered if patient has inability to control pain with adequate medications
- In patients with greater than 4-8 weeks symptoms not improving with time
Types of Surgeries
Lumbar fusion (PLIF,ALIF)
Intradiscal procedures -controversial
Backache, which after days or weeks yields to radicular pain. Exacerbation with coughing, sneezing, straining and relief upon flexing the knee and thigh. Backache per se is usually a minor symptom.
Signs include findings suggestive of nerve root impingement:
Pain radiating down LE
Dermatomal sensory changes
Nerve root tension signs
Nerve root tension signs include:
Femoral stretch test
Sitting knee extension
Cauda Equina Syndrome
Cauda equina syndrome is compression on bundle of spinal nerve roots called cauda equina. It is a surgical emergency to prevent lasting damage like paralysis or incontinence.
Causes include severe ruptured disc, narrowing of spinal canal (spinal stenosis), spinal lesion or tumor and infection, fracture or haemorrhage.
Clinical features include:
- Sudden or Gradual onset
- Low back pain and/or sciatica usually bilateral or unilateral or may be absent
- Pain, numbness, or weakness in one or both legs
- Loss of or altered sensations in your legs, buttocks, inner thighs, backs of your legs, or feet that is severe or gets worse and worse (called saddle anesthesia).
- Recent problem with bladder or bowel function, (retention) or trouble holding it (incontinence).
- Sexual dysfunction that has come on suddenly
Diagnosis is made on history, physical examination and MRI.
Treatment is discectomy or laminectomy within 24 hours.