Leg pain

Probability diagnosis

Muscle cramps

Nerve root ‘sciatica’

Varicose veins

Osteoarthritis (hip, knee)

Exercise-related pain (e.g. Achilles tendonitis), muscular injury (e.g. hamstring)

Serious disorders not to be missed

Vascular:

• peripheral vascular disease

• arterial occlusion (embolism)

• thrombosis popliteal aneurysm

• deep venous thrombosis

• iliofemoral thrombophlebitis

Neoplasia/cancer:

• primary (e.g. myeloma)

• metastases (e.g. breast to femur)

Infection:

• osteomyelitis

• septic arthritis

• erysipelas/cellulitis

• lymphangitis

• gas gangrene

Pitfalls (often missed)

Osteoarthritis hip

Osgood–Schlatter disorder

Spinal canal stenosis → neurogenic claudication

Herpes zoster (early)

Greater trochanteric pain syndrome

Nerve entrapment (e.g. meralgia paraesthetica)

‘Hip pocket nerve’

Iatrogenic: injection into nerve

Sacroiliac disorders

Complex regional pain syndrome I

Peripheral neuropathy

Rarities:

• osteoid osteoma

• polymyalgia rheumatica (isolated)

• Paget disease

• popliteal artery entrapment

• tabes dorsalis

• ruptured Baker cyst

Masquerades checklist

Depression

Diabetes

Drugs (indirect)

Anaemia (indirect)

Spinal dysfunction

Is the patient trying to tell me something?

Quite possible. Common with work-related injuries.

Key history

Ask:

• Is the pain acute or chronic onset?

• Did it follow trauma or activity?

• Is it ‘mechanical’ (related to movement)?

• Is it postural?

• Is it related to walking?

• Is the pain arising from bone or from a joint?

Past history, especially cardiovascular, back pain, trauma history.

Key examination

• Watch the patient walk and assess the nature of any limp. Note the posture of the back and examine the lumbar spine. Have both legs well exposed for inspection

• Palpate for local causes of pain and if no cause is evident examine the spine, blood vessels and bone. Note the temperature of the feet and legs

• Perform a vascular examination including the peripheral pulses and veins

• Consider a neurological examination to test nerve root lesions or entrapment neuropathies

• Examine the joints, especially the hip and sacroiliac joints

Key investigations

Consider:

• FBE and ESR

• radiology: plain X-ray, knee, hip, lumbosacral spine; CT or MRI, bone scan

• electromyography

• vascular studies: arterial tree or venous system.

Diagnostic tips

• Pain that does not fluctuate in intensity with movement, activity or posture has an inflammatory or neoplastic cause.

• Varicose veins can cause aching pain in the leg.

• Older people may present with claudication in the leg from spinal canal ...