Calf pain

Probability diagnosis

Simple muscular cramp

Muscle soreness (post exercise)

Muscle injury esp. gastrocnemius tear

Claudication esp. vascular (intermittent)

Serious disorders not to be missed

Vascular:

• Deep venous thrombosis

• Peripheral vascular disease

• Superficial thrombophlebitis

• Popliteal artery entrapment

Infection:

• Cellulitis

Other:

• Achilles tendon rupture

• Neurogenic claudication

• Deep posterior muscle compartment syndrome

Pitfalls (often missed)

Referred pain: knee, spine

Ruptured Baker’s cyst

Superficial posterior compartment syndrome

Nerve entrapment e.g. tibial, sural

Stress fracture of fibula

Rarities:

• Hypocalcaemia→cramps

• Motor neurone disease

Masquerades checklist

Diabetes

Drugs e.g. beta blockers

Thyroid/other endocrine: hypocalcaemia

Spinal dysfunction: L5 referred

Is the patient trying to tell me something?

Possibly muscle tension

Key history

A history of the features of the pain-quality, onset (acute or slow), ‘tearing’ or ‘popping’ sound, relation to activity and associations esp. back or knee pain.

Document any preceding sporting activity, travel, immobilisation, varicose veins or claudication—neurogenic or vascular pattern.

Key examination

• Calf muscle examination incl. Achilles tendon, functional stress, swelling or bruising

• Lumbosacral spine and knee of affected side

• Veins and arteries of leg esp. peripheral pulses

• Neurological—sensation, power, reflexes esp. ankle

Investigations

Nil for most cases.

Consider:

• FBE

• ESR/CRP

• muscle enzymes

• imaging e.g. ultrasound, D-dimer, venography, angiography

Diagnostic tips

Neurogenic claudication is muscular pain starting proximal and radiating distal on walking, and persists for a while after resting. Vascular claudication starts in the calf, radiates proximal and abates on rest.