Foot and ankle pain

Probability diagnosis

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

Serious disorders not to be missed

Vascular insufficiency:

• small vessel disease

Neoplasia/cancer:

• osteoid osteoma

• osteosarcoma

• synovial sarcoma

• acral lentiginous melanoma

Infection (rare):

• septic arthritis

• actinomycosis

• osteomyelitis

Rheumatoid arthritis

Peripheral neuropathy

Complex regional pain syndromes

Ruptured Achilles’ tendon

Ruptured tibialis posterior tendon

Pitfalls (often missed)

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

Masquerades checklist

Diabetes

Drugs

Spinal dysfunction

Is the patient trying to tell me something?

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

Key history

Ask about the quality of the pain, its distribution, mode of onset, periodicity, relationship to weight-bearing and associated features such as swelling or colour change. Enquire about pain in other joints including sacroiliac joints.

Key examination

• 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 and perform a neurological examination including sensation, motor strength and reflexes

Key investigations

Consider:

• FBE

• ESR/CRP

• rheumatoid arthritis tests

• blood glucose

• uric acid

• nerve conduction studies and imaging (e.g. plain X-ray—compare both sides)

• ultrasound

• MRI

• radionuclide scans.

Diagnostic tips

• 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.