Low Back Pain

• Low Back Pain


  • Very common
  • 90% of the time there's a mechanical reason
  • 10% due to systemic illness
• Types of Low Back Pain (triage)

  • Non-specific LBP
  • Radicular pain
  • Serious spinal pathology
  • Cauda Equina Syndrome
  • Inflammatory Disorders
  • Disease of abdominal or pelvic organs
  • Violent trauma
• Cauda Equina Syndrome presents with constant, progressive, non-mechanical pain, previous history of cancer, systemic corticosteroids, drug abuse, and signs of systemic illness
• Cauda Equina Syndrome requires urgent assessment for incontinence of urine or stool and paraesthesia
• Radicular leg pain is common, as is bowel and/or bladder dysfunction, and saddle anaesthesia
• Do not wait for a patient to develop urinary or bowel dysfunction before referring them
• Ankylosing Spondylitis

  • Peak onset 15-25 yoa
  • Male:Female ratio 3:1
  • 1-2% of HLA-B27 positive patients develop AS, increases to 18-20% with an affected first-degree relative
  • Most patients have mild, chronic disease with periods of remission
  • Fatigue is common
  • Morning stiffness is characteristic
  • Peripheral enthesitis is common
  • classically affects SIJs bilaterally then ascends to spine
• Inflammation in Ankylosing Spondylitis primarily affects the axial skeleton and appears to originate in ligamentous and capsulated sites of attachment to bones
• Ankylosing Spondylitis classically affects the sacroiliac joints bilaterally then ascends the spine, commonly affecting the thoracolumbar region, costal articulations, and cervical spine
• Complications of Ankylosing Spondylitis

  • Iritis
  • Aortic regurgitation
  • Heart valve disease
  • Incompetence
  • Aortic aneurysm
  • Conduction block
  • Upper lobe fibrosis
  • Pulmonary fibrosis
  • Inflammatory bowel disease
  • Renal involvement
  • Neurological involvement
• In children under 10, it is especially important to exclude organic disease as a cause of back pain
• Spondylolisthesis


  • Forward slippage of a vertebra on the one below
  • 4 most common at L5
  • 2 common types: Dysplastic (secondary to congenital defect), Lytic (lesion at pars interarticularis, most likely in people under 30), Degenerative (due to degeneration of facet joints, can allow forward or backward slippage, common in older patients)
  • Spondylolytic spondylolisthesis (type 2) is most common at L5/S1
  • Symptoms most common between ages of 7-20, associated with exposure to high loads (e.g. gymnasts, divers, pole vaulters, wrestlers, dancers)
• Spondylolisthesis can cause low back pain with radiation to the buttock and thigh, waddling gait, anterior rotation of the pelvis, paraspinal muscle tightness, and restricted flexion of the hips
• Special problems to consider in back pain in the elderly

  • Malignant disease
  • Degenerative spondylolisthesis
  • Vertebral pathological fractures
  • Osteoporosis
  • Degenerative joint disease (can lead to stenosis)
  • Occlusive vascular disease
• In cervical spine radicular presentations, the clinician must also look carefully for associated spinal cord features such as altered gait, balance problems, lower limb weakness and paraesthesia, and bowel or bladder dysfunction
• In the lumbar spine, central canal lesions can affect the cauda equina, and the central aspect is the most concerning region
• Cauda equina compression can lead to reversible neurological deficits, and any onset of bowel or bladder disturbance requires urgent investigation as it is a surgical emergency
• Mechanical forces affecting nerve roots

  • Compression
  • Traction
  • Friction
• Chemical irritation may also affect nerve roots, including ischaemia, vascular compression, and inflammatory mediators generated with tissue injury
• Neurotmesis (complete nerve transection) does not occur in root syndromes unless there is significant traction trauma
• Many people can have quite advanced foraminal stenosis and no radicular symptoms, as there is a large functional reserve for nerve roots
• The development of radicular pain or radiculopathy is more than just simple nerve root compression - the rate, magnitude, and sustained nature of compression are also important factors in the degree of oedema, impaired vascular flow, and conductive changes that can reduce the capacity for recovery
• A radiculopathy that comes on quickly, rapidly progresses to give marked sensory-motor findings, and is sustained for 3-4 weeks, is less likely to recover completely
• Most lumbar radicular pain and radiculopathy involves the L5 or S1 nerve roots, related to spondylosis or disc herniation
• L4 is the next most commonly affected nerve root, still often due to a mechanical cause but with a higher probability of a non-mechanical cause
• S2-S4 compromise is not common, most often due to degenerative changes or disc herniation, but the nature of this compromise is serious
• A thorough history and examination can nearly always identify the presence of radicular pain and radiculopathy, but it is not always easy to identify the exact nerve root involved due to variation in the distribution of sensory and motor nerves
• Dermatomes are quite unreliable, but become more reliable below the knee
• Radicular pain is usually limited to the dermatome and is sharp, shooting, and superficial, while non-radicular pain is often diffuse, poorly localised, and deep, and may feel like cramping
• Most often, radicular pain radiates below the knee
• If radicular pain is secondary to nerve root encroachment, the leg pain may be relieved on sitting bringing the knees to the chest and worse on standing and walking, while if it is secondary to disc herniation the leg pain will be worse with prolonged sitting
• Nerve root irritability, with increased mechanical sensitivity, may be one of the earliest signs of radicular pain
• Spontaneous pain and night pain are quite common in radicular pain
• After the initial pain provocation, refractory pain may be produced over the mechanical provocation
• Signs of nerve root irritability in the lower extremity

  • Supine straight leg raise (most neurodynamic effect on L5-S1 nerve roots)
  • Slump test
  • Prone knee chest (most neurodynamic effect on L4-L1 nerve roots)
  • Seated or standing Valsalva may take several seconds before symptoms start
• Weakness is one of the most important signs to recognise, as significant weakness suggests the potential for permanent loss and requires referral for special investigation
• Weakness is often mild due to bisegmental innervation and the root lesion often being incomplete, which can also result in minimal atrophy
• Fasciculations can arise from a lesion anywhere along the course of the motor neuron, but are most commonly seen when the cell body is degenerating (hyperexcitable)
• Primary general clinical indications for surgical opinion

  • Persistent intractable pain that does not improve with adequate trial of non-surgical care
  • Progressive root neurological deficits that do not improve with adequate trial of non-surgical care
  • Severe motor loss, even if recent onset
  • Presence or progression to signs of Cauda Equina Syndrome
• Sensory symptoms in radiculopathy arise from a combination of nerve irritability and neuropraxial axonotmesis (damage to the nerve root)