Acute Lower Back Pain

Last Updated on by frcemuser


Emergency departments see many patients presenting with acute back pain but they also see many patients with acute exacerbations of a chronic back problem and patients with back pain incidental to their presenting problem.

Red flag symptoms indication possible serious spinal pathology

  • Onset at age <20 or >55
  • Non-mechanical pain (i.e. unrelated to time or activity), especially if constant and worsening and pain at night
  • Thoracic pain
  • Previous history of carcinoma, steroids or HIV infection
  • Fever, night sweats, weight loss
  • Widespread neurological symptoms especially sphincter disturbance
  • Structural spinal deformity

Differential Diagnosis

Causes of low back pain

  • Mechanical or non-specific
  • Facet joint arthritis or dysfunction
  • Prolapsed intervertebral disc
  • Annular tear of intervertebral disc
  • Spondylolysis or spondylolisthesis
  • Spinal stenosis
  • Primary or secondary including multiple myeloma
Referred pain to spine from
  • Major viscera
  • Retroperitoneal structures
  • Aorta
  • Hip
  • Discitis
  • Osteomyelitis
  • Paraspinal abscess
  • Spondyloarthropathies
  • Sacroiliitis or sacroiliac dysfunction
  • Osteoporotic vertebral collapse
  • Pagets disease
  • Osteomalacea
  • Hyperparathyroidism


Cauda equina syndrome

  • Bilateral sciatica
  • Severe or progressive bilateral neurological deficit
  • Difficulty initiating micturition or impaired sensation of urinary flow,
  • Urinary retention with overflow urinary incontinence
  • Loss of sensation of rectal fullness and feacal incontinence with laxity of the anal sphincter
  • Perianal, perineal or genital sensory loss – saddle anaesthesia or paraesthesia
  • A cauda equina syndrome (or spinal cord compression) is a surgical emergency that needs to be operated on within 24 hours after the onset of bladder symptoms

Non traumatic compression fractures

Risk Group

  • Postmenopausal women
  • women older than 50 years of age
  • History of metastases and multiple myeloma


Spondylolisthesis is a forward slippage of one vertebra on another. The most common sites are a spondylolisthesis of L5 on S1 and L4 on L5.


Spinal infection, including tuberculosis (TB) is an uncommon cause of back pain but must be considered

An Intravenous Drug User with Back Pain- consider Discitis.Discitis that can have potentially catastrophic consequences including sepsis and epidural abscess formation

The typical clinical features of discitis include:

  • Back or neck pain
  • Pain often awakes patient from sleep
  • Fever
  • Neurological deficits
  • Children sometimes refuse to walk

Risk factors for developing discitis include:

  • Spinal surgery
  • Immunodeficiency
  • Intravenous drug use
  • Age less than 8 years
  • Diabetes mellitus
  • Malignancy

causative organism

  • common – Staphylococcus aureus.
  • Streptococcus viridan in intravenous drug users
  • Other possible organisms include Gram-negative organisms such as Escherichia coli, and Mycobacterium tuberculosis (Pott’s disease)


Patients with a history of malignancy may have non-specific back pain but metastasis should always be considered.

  • 50yrs
  • Gradual onset of symptoms.
  • Severe unremitting pain that remains
  • Night pain
  • Throacic pain
  • Worse with coughing/ sneezing
  • Localised spinal tenderness.
  • No symptomatic improvement after four to six weeks
  • Unexplained weight loss.
  • Past history of cancer


  • No investigation is required for the vast majority of patients with non-specific back pain
  • urgent MRI scanning- Red flag symptoms or signs suggestive of cauda equina syndrome or infections
  • Blood tests may be useful if one suspects infection or metabolic problems


Symptomatic treatment of acute musculoskeletal lower back pain

  • Analgesia eg NSAID
  • Muscle relaxants
  • Physiotherapy

Treatment of sciatica

  • Analgesia
  • consider Epidural injection/ surgical discectomy

Treatment of vertebral compression fractures

  • analgesia / Spinal support /Surgery may be considered
  • osteoporosis will also need to be investigated and manage

Treatment of metastatic disease

Patients with bone metastases and patients at high risk of developing bone metastases should be given information explaining what to do and who to contact if they develop symptoms of spinal metastases or spinal cord compression

Spinal cord compression is an oncological emergency and treatment should be started within 24 hours. Most patients will be given steroids and will need radiotherapy or surgery

Follow up

Follow up (if required) is not the role of the emergency physician but may be required by general practitioners, orthopaedic surgeons, spinal surgeons, geriatricians or rehabilitation teams


Acute Lower Back Pain

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