What is the best initial step to identify the cause of toe-standing pain?

Best Initial Step to Identify the Cause of Toe-Standing Pain

The best initial step to identify the cause of toe-standing pain is to perform weight-bearing radiographs of the foot as the first imaging study for chronic foot pain of unknown etiology. 1

Comprehensive Assessment Approach

History Taking (Critical Elements)

• Previous foot ulceration or amputation history 1
• History of leg fatigue, claudication, or rest pain relieved with dependency 1
• Neuropathic symptoms (pain, burning, numbness) 1
• Smoking history and exercise tolerance 1
• History of diabetes management 1
• Previous foot deformities or surgeries 1

Physical Examination Components

1. Skin Integrity Assessment

   • Look for ulcerations, calluses, erythema, or warmth 1
   • Check for signs of infection or inflammation 1

2. Neurological Assessment

   • 10-g monofilament testing (primary test) 1
   • At least one additional test from: 1
     • Pinprick sensation
     • Temperature perception
     • Vibration testing with 128-Hz tuning fork
     • Ankle reflex assessment

3. Vascular Assessment

   • Palpation of dorsalis pedis and posterior tibial pulses 1
   • Assessment of capillary refill time 1
   • Check for rubor on dependency and pallor on elevation 1
   • Venous filling time 1

4. Structural Assessment

   • Foot deformities (bunions, hammertoes, prominent metatarsals) 1
   • Assessment of plantar foot pressures 1
   • Gait evaluation 2
   • Weight-bearing and non-weight bearing examination 2

Diagnostic Imaging Algorithm

1. Initial Imaging: Weight-bearing Radiographs 1, 3

   • High specificity (88-96%) for detecting stress fractures 1
   • Excellent for identifying tarsal coalitions (sensitivity 80-100%, specificity 97-98%) 1
   • Can detect sesamoid dislocation, osteoarthritis, and distinguish bipartite from fractured sesamoid 1

2. If radiographs are negative or equivocal:

   • For plantar heel pain: MRI foot without IV contrast or ultrasound 3
   • For midfoot pain of suspected osseous origin: MRI foot without IV contrast or CT foot without IV contrast 3
   • For entrapment syndromes: MRI foot without IV contrast 3

3. For suspected peripheral arterial disease:

   • Refer for noninvasive arterial studies (Doppler ultrasound with pulse volume recordings) 1
   • Consider ankle-brachial index for patients >50 years or those with risk factors 1

Special Considerations

• Diabetic patients require more frequent foot examinations and comprehensive evaluation for peripheral neuropathy and arterial disease 1
• Patients with loss of protective sensation need education on alternative ways to examine their feet (palpation or visual inspection with an unbreakable mirror) 1
• Patients with prior ulceration or amputation should have their feet inspected at every visit 1

Common Pitfalls to Avoid

1. Relying solely on radiographs for all diagnoses

   • Radiographs have limited sensitivity (12-56%) for stress fractures 1
   • Insensitive for Morton's neuroma and plantar fasciitis 1

2. Skipping neurological assessment in diabetic patients

   • Peripheral sensory neuropathy is the single most common component cause for foot ulceration 1

3. Overlooking vascular assessment

   • Peripheral arterial disease significantly increases risk of complications 1

4. Starting with advanced imaging

   • No evidence supports using MRI, CT, or bone scan as initial imaging studies 1
   • These should be reserved for cases where radiographs are negative or equivocal 3

By following this systematic approach with weight-bearing radiographs as the initial imaging study, clinicians can effectively identify the cause of toe-standing pain and develop an appropriate treatment plan that addresses the underlying pathology.