Ankle and Foot Pain

Overview

Epidemiology

Foot pain is more common among people who wear uncomfortable shoes (usually women).

Classification

• Acute: lasts < 2 weeks 
• Chronic: lasts > 2 weeks

History

• Pain history (localization, quality, time, factors that alleviate/reinforce pain) 
• Pay attention to alarming symptoms: 
  • Severe pain, fever, warmness, and skin redness may indicate septic arthritis.
  • Inability to walk 4 steps immediately after injury → likely fractured
  • Numbness or weakness → likely fractured with compressed or injured nerve

Physical examination

Ottawa ankle and foot rules:

• High sensitivity, poor specificity for fractures
• Most helpful when negative → no need for an X-ray

Differential Diagnosis

The etiology of ankle or foot pain can be determined from the anatomical location of the maximum point of pain or tenderness.

Diagnostic workup:

• General lab investigations (CBC, erythrocyte sedimentation rate [ESR], C-reactive protein [CRP]) to exclude infectious causes and autoimmune conditions
• Imaging studies:
  • X-ray looking for fractures
  • Magnetic resonance imaging (MRI) to assess soft tissues
  • Bone scan to evaluate for osteoporosis in elderly patients

Management

• Stress fracture:
  • The mainstay of treatment is reducing weight-bearing, then immobilization for 4–6 weeks.
  • Referral to an orthopedic surgeon if there is a fracture at high risk for malunion:
    • Anterior tibial cortex
    • 5th metatarsal
• Ankle sprain: (RICE [rest, ice, compression, elevation] is the usual prescribed therapy for the first 2-3 days, but there is no good data about its effectiveness as the sole therapy).
  • Early mobilization with a range of motion exercises.
  • Cooling
  • Compression
  • Acetaminophen/nonsteroidal anti-inflammatory drugs (NSAIDs)
  • Consider physiotherapy, particularly for patients at risk of recurrence
• Morton neuroma:
  • Strength exercises for the intrinsic foot muscles (metatarsal support)
  • Bar or padded shoe inserts to decrease pressure on the metatarsal heads
  • A single injection of a glucocorticoid and local anesthetic if persistent
  • Surgery is usually reserved for patients who fail conservative treatment.
  • Rarely, a neuroma may recur following surgery.
• Calluses and corns:
  • Application of salicylic acid plasters
  • Patients should be advised to avoid ill-fitting shoes.
• Plantar warts:
  • Topical salicylic acid and cryotherapy with liquid nitrogen
• High-arched feet (pes cavus) and flat feet (pes planus):
  • Orthotic devices
  • Shoe modifications
  • Bracing
• Plantar fasciitis:
  • Stretching exercises for the plantar fascia and calf muscles
  • Avoid the use of flat shoes and barefoot walking.
  • Use arch supports and/or heel cups.
  • Decrease physical activities (e.g., excessive running, dancing, or jumping).
  • Short-term trial (2–3 weeks) of NSAIDs
  • If all previous measures fail, consider injecting the tender areas of the plantar region with glucocorticoids and a local anesthetic.
• Calcaneal apophysitis (Sever’s disease):
  • Bilateral use of a heel cup or lift
  • Decreased level of participation in painful activities
  • Daily ice packs to the area for 20 minutes along with calf muscle stretching and strengthening
  • NSAIDs as needed against pain during the initial treatment stage

Clinical Relevance

The following are common conditions associated with ankle and foot pain:

• Ankle joint: also called the talocrural joint, the ankle joint is a true hinge joint formed between the articular surfaces of the distal tibia, distal fibula, and the talus. The ankle joint functions as a hinge joint allowing plantar flexion, dorsiflexion, and a small degree of abduction, adduction, and rotation.
• Disseminated gonococcal infection: an infection that often occurs in sexually active young patients. It may present with asymmetric polyarthralgia (often but not always associated with tenosynovitis and skin rash) or an isolated septic monoarthritis or oligoarthritis. Diagnosis requires joint aspiration and analysis and is confirmed by Gram stain of the synovial fluid, blood cultures, and genital/pharyngeal nucleic acid amplification tests for Neisseria gonorrhoeae. 
• Rheumatoid arthritis: a chronic inflammatory systemic disease that progresses in stages. The basis of the disease is an inflammation of the synovial membrane, i.e., the inner layer of the joint capsule. Attributed to synovitis, it can lead to secondary diseases such as arthritis, bursitis, or tenosynovitis.
• Osteoarthritis: a degenerative disorder of the articular cartilage, along with the subchondral bones and other joint structures. Osteoarthritis is the most common type of joint disease and the leading cause of disability in older adults. The main risk factors for osteoarthritis are a family history of the disease, female gender, past trauma to the involved joint, aging, and obesity.
• Gout: defined by uric acid precipitation in the tissue (joints, tophi, and kidneys). An acute gout attack represents exacerbated hyperuricemia. A gout attack often occurs at night with monoarthritis. In 90% of cases, the gout attack affects the first metatarsophalangeal joint (podagra). Signs of acute joint gout include reddening, swelling, and extreme contact pain. Fever due to cytokine production and development of systemic inflammation may also be found.
• Pseudogout: calcium pyrophosphate dihydrate crystals deposition in the periarticular tissues of joints and soft tissue. Pseudogout can induce remarkable damage to the affected joints. Symptoms include pain, swelling, and heat in the affected joint. Diagnosis is made by identification of positively birefringent CPP crystals by compensated polarized light microscopy in the aspirated joint fluid.
• Anorexia nervosa: an eating disorder marked by self-imposed starvation and inappropriate dietary habits due to a morbid fear of weight gain and disturbed perception of body shape and weight. Patients have strikingly low body weight (BMI < 18.5) and diverse physiological and psychological complications. One of the common complications of anorexia nervosa is stress fractures.