What is the most appropriate initial evaluation and management for a 57‑year‑old woman with mid‑foot pain radiating up her leg?

Mid-Foot Pain with Radiation in a 57-Year-Old Woman

The most appropriate initial evaluation is a comprehensive foot examination focusing on neurological assessment (10-g monofilament or Ipswich touch test plus pinprick/temperature/vibration), vascular assessment (pedal pulses, capillary refill), and inspection for deformities, followed by weight-bearing radiographs of the foot if no exclusionary criteria exist. 1

Immediate Clinical Assessment Priorities

History Elements That Guide Diagnosis

• Determine if diabetes is present or suspected, as diabetic neuropathy fundamentally changes the diagnostic approach and can cause painless fractures despite significant injury 1
• Assess for systemic inflammatory signs (fever, rapid progression, extensive necrosis) that would indicate urgent surgical consultation 1
• Characterize the pain quality: burning/electric pain suggests nerve entrapment (lateral plantar nerve), while mechanical pain worsening with weight-bearing suggests osseous or articular pathology 1, 2, 3
• Obtain smoking history, prior ulceration/amputation, and vascular symptoms (leg fatigue, claudication, rest pain) as these indicate high-risk foot requiring immediate podiatric referral 1

Critical Physical Examination Findings

• Neurological testing is mandatory: Use 10-g monofilament testing or Ipswich touch test plus at least one additional modality (pinprick, temperature, vibration) to detect loss of protective sensation 1
• Vascular assessment: Palpate pedal pulses, assess capillary refill time, check for rubor on dependency and pallor on elevation 1
• Localize tenderness precisely: Point tenderness over the dorsal midfoot suggests stress fracture or extensor tendonitis; lateral foot tenderness suggests lateral plantar nerve entrapment; plantar tenderness with dorsal swelling indicates deep-space infection requiring urgent surgery 1, 2, 3
• Perform Tinel's sign along the lateral plantar nerve distribution to identify nerve entrapment as the source of radiating pain 2
• Examine both feet comparatively and evaluate gait pattern, as bilateral findings suggest systemic disease 4, 5

Initial Imaging Strategy

When Radiographs Are Indicated

Obtain weight-bearing radiographs (anteroposterior, oblique, lateral views) as the first imaging study for all patients with midfoot pain, as this detects fractures with 80-100% sensitivity and identifies osteoarthritis, tarsal coalitions, and bony deformities 1, 6, 3

Critical Exception: Diabetic Neuropathy

If diabetic neuropathy or neurological compromise is present, obtain radiographs even without pain or point tenderness, as these patients may walk without discomfort despite fractures due to poor pain proprioception 1

When Advanced Imaging Is Required

If Radiographs Are Normal But Pain Persists

Order MRI of the foot without contrast as the next diagnostic step, as this provides the highest yield for detecting:

• Occult stress fractures (initial radiographs detect only 12-56% of stress fractures) 1, 2, 3
• Plantar plate tears (MRI has 87% sensitivity) 2
• Nerve entrapment syndromes 2
• Soft tissue pathology not visible on radiographs 1, 2

Ultrasound is an acceptable alternative if MRI is unavailable, particularly for plantar plate tears (96% sensitivity) and direct nerve visualization in entrapment syndromes 2

Urgent Referral Criteria

Immediate Surgical Consultation Required

Seek urgent surgical consultation if any of the following are present:

• Evidence of systemic inflammatory response or rapid progression 1
• Plantar wound with dorsal erythema or fluctuance (suggests infection through fascial compartments) 1
• Unexplained persistent foot pain or tenderness suggesting deep-space infection 1
• Critical limb ischemia (absent pulses, rest pain, tissue loss) 1
• Extensive soft tissue loss or bony destruction, especially midfoot/hindfoot 1

Podiatric Referral Indications

Refer to podiatric foot and ankle surgeon if:

• Loss of protective sensation is detected on neurological examination 1
• History of prior ulceration, amputation, or Charcot foot 1
• Patient is on dialysis 1
• Smoking history with structural abnormalities or peripheral arterial disease 1
• No improvement after 6 weeks of conservative treatment 1

Initial Management While Establishing Diagnosis

• NSAIDs for pain control and anti-inflammatory effect are appropriate while awaiting imaging results 1, 6
• Activity modification avoiding repetitive loading helps manage symptoms 2
• Avoid corticosteroid injection until diagnosis is confirmed, particularly near tendons where injection risks tendon rupture 1, 3
• Open-backed shoes or accommodative padding may provide symptom relief for posterior heel or insertional pathology 1

Common Diagnostic Pitfalls

• Do not dismiss the diagnosis based on normal radiographs alone, as stress fractures have very low initial sensitivity on plain films and require 2-3 weeks for periosteal reaction to become visible 1, 2, 3
• Do not overlook nerve entrapment when pain has a radiating quality, as lateral plantar nerve entrapment causes pain radiating from the midfoot up the leg and requires different management than osseous pathology 1, 2
• In diabetic or neuropathic patients, absence of fever or leukocytosis should not dissuade surgical exploration if deep infection is suspected 1
• Reexamine 3-5 days post-injury if initial examination was limited by swelling, as excessive swelling within 48 hours can obscure findings 2
• Do not rely on ankle-brachial index alone to determine vascular intervention need; consider multiple clinical parameters 1