Back pain, lower

Probability diagnosis

Vertebral dysfunction especially facet joint and disc (mechanical pain)

Musculoligamentous strain/sprain

Spondylosis (degenerative OA)

Serious disorders not to be missed

Cardiovascular:

• ruptured aortic aneurysm

• retroperitoneal haemorrhage (anticoagulants)

Neoplasia/cancer:

• myeloma

• pancreas

• metastases (e.g. lung, breast, prostate)

Infection:

• vertebral osteomyelitis

• epidural/subdural abscess

• septic discitis

• tuberculosis

• pelvic abscess/PID

• pyelonephritis

Other:

• osteoporotic compression fracture

• cauda equina compression

Pitfalls (often missed)

Spondyloarthropathies:

• ankylosing spondylitis

• reactive arthritis

• psoriasis

• bowel inflammation

Sacroiliac dysfunction

Spondylolisthesis

Spinal canal stenosis

Claudication:

• vascular

• neurogenic

Paget disease

Prostatitis

Endometriosis

Masquerades checklist

Depression

Spinal dysfunction

UTI

Is the patient trying to tell me something?

Quite likely. Consider lifestyle, stress, work problems, malingering, conversion reaction.

Key history

Routine analysis of pain (SOCRATES approach), especially intensity of pain and its relation to rest and activity and also diurnal variation. Ask about pain on standing, sitting and walking with types of claudication (if any).

   Review family history, occupational history, drug history, psychosocial history and ask questions about red flags that are alarm symptoms of serious disease.

Key examination

Follow the LOOK, FEEL, MOVE, MEASURE clinical approach with an emphasis on palpation—central and lateral.

   The movements with normal ranges are:

• extension 20°–30°

• forward flexion 75°–90°

• lateral flexion (left and right) 30°.

Perform a neurological and vascular examination of the lower limb/s with pain.

Key investigations

This should be conservative, especially in the absence of red flags. Basic screening is:

• FBE

• ESR/CRP

• urinalysis

• serum alkaline phosphatase

• PSA in males 50–75 years

• plain X-ray if chronic pain and red flags.

Reserve CT scan, MRI or radionuclide scan for suspected serious disease (malignancy and infection).

Diagnostic tips

• Continuous pain (day and night) points to neoplasm (esp. malignancy) or infection.

• Pain (and stiffness) at rest, relief with activity indicates inflammation (e.g. spondyloarthropathy).

• Pain provoked by activity with relief at rest indicates mechanical (vertebral) dysfunction.

• Pain in the periphery of the limb can be discogenic causing radicular pain or spinal cord stenosis causing neurogenic claudication or vascular causing intermittent claudication.