Leg Pain

INTRODUCTION

SPINAL CAUSES OF LEG PAIN

Problems originating from the spine are an important, yet at times complex, cause of pain in the leg. Important causes are:

• nerve root (radicular) pain from direct pressure, esp. sciatica (L4–S3) ( 57–8)

• referred pain from:

  • – disc pressure on tissues in front of the spinal cord

  • – apophyseal joints

  • – sacroiliac joints

• spinal canal stenosis causing claudication

VASCULAR CAUSES OF LEG PAIN

Occlusive arterial disease

Acute lower limb ischaemia

Sudden occlusion whether by embolism or thrombosis is a dramatic event which requires immediate diagnosis and management to save the limb.

Signs and symptoms—the 6 Ps

• Pain

• Pulselessness

• Pallor

• Paralysis

• Paraesthesia or numbness

• ‘Perishing’ cold

Management of acute ischaemia

Golden rules: Occlusion is usually reversible if treated within 4 h (i.e. limb salvage). It is often irreversible if treated after 6 h (i.e. limb amputation).

Treatment

• Unfractionated heparin (immediately) 80 U/kg IV

• Emergency embolectomy (ideally within 4 h) or

• Arterial bypass if acute thrombosis in chronically diseased artery or

• Stenting of vessels

• Amputation (early) if irreversible ischaemic changes

Lifelong anticoagulation may be needed.

Chronic lower limb ischaemia

Chronic ischaemia caused by gradual arterial occlusion can manifest as intermittent claudication or rest pain in the foot. Investigate with ankle-brachial index: <0.9 suggestive PAD, <0.5 likely severe PAD; CT angiography.

Treatment

• General measures (if applicable): control obesity, diabetes, hypertension, hyperlipidaemia, cardiac failure

• Achieve ideal weight

• Absolutely no smoking (the risk factor)

• Exercise: daily graduated exercise to the level of pain; approx. 50% will improve with walking so advise as much walking as possible

• Try to keep legs warm and dry

• Maintain optimal foot care (podiatry)

• Drug therapy: aspirin 150 mg daily + a statin; consider ACEI

Note: Vasodilators and sympathectomy are of little value. ~1/3 progress, while the rest regress or don’t change.

When to refer to a vascular surgeon

• ‘Unstable’ claudication of recent onset; ...