Foot and ankle pain

Question 1

Probability diagnosis

Answer 1

Acute or chronic foot strain

Sprained ankle

Osteoarthritis (esp. great toe – hallux rigidus)

Plantar fasciitis

Achilles tendonopathy

Tibialis posterior tendonopathy

Wart, corn or callus

Ingrowing toenail/paronychia

Question 2

Serious disorders not to be missed

Answer 2

Vascular insufficiency:

• small vessel disease
• diabetic neuropathy

Neoplasia/cancer:

• osteoid osteoma
• osteosarcoma
• synovial sarcoma
• acral lentiginous melanoma

Infection (rare):

• septic arthritis
• actinomycosis
• osteomyelitis

Rheumatoid arthritis

Foreign bodies (e.g. needles, in children)

Peripheral neuropathy

Complex regional pain syndromes

Ruptured Achilles’ tendon

Ruptured tibialis posterior tendon

Question 3

Pitfalls (often missed)

Answer 3

Foreign body (especially children)

Gout

Nerve syndromes:

• Morton neuroma
• tarsal tunnel syndrome
• deep peroneal nerve

Chilblains

Stress fracture (e.g. navicular)

Erythema nodosum

Rarities:

• spondyloarthropathies
• osteochondritis: navicular (Köhler), metatarsal head (Freiberg), calcaneum (Sever)

Glomus tumour (under nail)

Paget disease

Question 4

Masquerades checklist

Answer 4

Diabetes

Drugs

Spinal dysfunction

Question 5

Is the patient trying to tell me something?

Answer 5

A non-organic cause warrants consideration with any painful condition.

Question 6

Key history

Answer 6

Ask about the quality of the pain, its distribution

Mode of onset and periodicity

Relationship to weight-bearing

Aassociated features such as swelling or colour change.

About pain in other joints including sacroiliac joints.

Question 7

Key examination

Answer 7

Follow the inspection, palpation, movement and test function approach

Test active and passive movements of the ankle (talar) joint, hindfoot (subtalar) joint and mid-foot (midtarsal) joint

Check the peripheral circulation

Perform a neurological examination including sensation, motor strength and reflexes

Question 8

Key investigations

Answer 8

FBE

ESR/CRP

rheumatoid arthritis tests

blood glucose

uric acid

• nerve conduction studies
• imaging (e.g. plain X-ray—compare both sides)
• ultrasound
• MRI
• radionuclide scans.

Question 9

Diagnostic tips

Answer 9

Good quality plain X-rays are important if there is doubt about the diagnosis of a painful foot.

Foot strain is probably the commonest cause of podalgia.

All the distal joints of the foot may be involved in arthritic disorders.

Question 10

Foot pain (podalgia)

Question 11

Morton neuroma

Question 12

Frostbite

Question 13

Heel pain