Acute non-traumatic back pain



Back pain may be due to 1. mechanical back pain 2. neurogenic pain, 3. pathological pain and 4. inorganic pain


Mechanical back pain

  • Is due to sprain of the spinal ligaments or arthritis in the facet joints.
  • Confined to the back (occasionally referred into the upper leg).
  • Exacerbated by movement.
  • Relieved by rest.
  • If pain at night, it is when they roll over.
  • PMHx of similar problem / previous injury making back more susceptible.

Red flags

  • Age >55 or <19
  • Night pain
  • Thoracic back pain
  • Bilateral neurological symptoms
  • Sphincter symptoms
  • Immunosuppression (or IVDU) Hx
  • Hx malignancy
  • Fever
  • Coagulopathy

Neurogenic pain

  • Nerve root is irritated by prolapsing lumbar disc, # or osteophyte.
  • Pain and paraesthesia.
  • Distribution consistent with that nerve root.
    • Paraesthesia is in the same distribution:
      • L4: pain extends into the medial malleolus.
      • L5: into the lateral malleolus and big toe.
      • S1: pain into the lateral border of the foot and little toe.
  • Worsening disease results in loss of sensation / power / reflex.
    • Distribution is characteristic for each nerve root.

Pathological pain

  • Nasty, unpleasant pain at rest.
  • Nocturnal pain prominent.
  • Due either to malignant disease or infection.
  • If neurological symptoms,may initially seem fluctuant / inconsistent.
  • Neurological dysfunction can rapidly result if it is not resolved.
  • Past History:
    • Thoracotomy.
    • Mastectomy.
    • Prostatectomy.
Sclerotic prostatic Secondary in Body of T12

Exam - non-traumatic back pain

Examine spine

  • History, history, history.
  • Look ( scoliosis, loss of lordosis, spasm).
  • Feel ( tender vertebra/rib, step betw spinous process).
  • Move - limitation and pain.

Please remember AAA and retroperitoneal pathology (pyelonephritsis, haematoma, pancreatitis) may present as back pain and consider appropriate tests (US AA in all older patients with back pain).

Neurology

  • Sensation (including perianal pin prick).
  • Coordination (CNS/cord lesion).
  • Power and reflexes.
  • SLR/sciatic stretch test.
  • Femoral nerve stretch test.
  • FAIR (hip flex/add/int. rotation) - piriformis pathology.

Beware of stiffness in young people associated with sclerosis or obliteration of SI joints. Check viscosity/ESR.


Sciatic (L5 root) vs other pathology

Sciatic nerve (L5): weak ankle dorsiflexion/plantarflexion, foot inversion/eversion; absent ankle jerk. May have weak knee flexion. Weak hip abduction if L5 lesion (sup gluteal nerve)

Piriformis syndrome: Trigger point in buttock. Treat with physio.

Iliotibial band syndrome: Recent Δ activity or footwear (inversion). Trigger with Ober's test and weak popliteus.

Peroneal nerve pathology: Hx Local trauma (fibular neck), tender peroneal nerve, weak ankle dorsiflexion and foot eversion, but strong ankle plantarflexion and foot inversion, normal AJ, paraesthesia dorsum of the foot only.

Cortical lesion: +ve Babinski.

Cauda equina: bilateral symptons ± sphincter (see below).


Central disc prolapse - cauda equina

  • Leg signs are less clear.
  • Loss of perianal sensation (pin prick).
  • Lax anal sphincter.
  • Micturition difficulty.
  • It is a medical emergency.

X-rays required if:

  • Direct trauma.
  • Preceding back problems or relevant Hx.
  • Patients with neurological signs or unable to stand.
  • Elderly.
  • Referred for orthopaedic opinion! (They are not indicated but the team will insist anyway).

Content by Dr Íomhar O' Sullivan 23/06/2000. Reviewed byDr ÍOS 15/03/2004, 25/05/2005, 23/05/2006, 22/05/2007. Last reviewed Dr ÍO 4/06/21.