What are the appropriate management and treatment options for an adult patient, possibly with a history of physical activity or conditions like diabetes or arthritis, presenting with plantar foot pain?

Management of Plantar Foot Pain in Adults

Start with plain radiographs as your initial imaging study for chronic plantar foot pain of unknown etiology, as conventional radiography is the first-line diagnostic tool to distinguish among different causes. 1

Initial Clinical Assessment

Key History and Physical Examination Elements

• Assess for diabetes and peripheral neuropathy: Check for loss of protective sensation using a 10-g monofilament test at minimum, ideally combined with pinprick, temperature, vibration (128-Hz tuning fork), or ankle reflex testing 1
• Evaluate vascular status: Palpate pedal pulses and assess for peripheral arterial disease (PAD) signs including decreased walking speed, leg fatigue, and claudication 1
• Identify foot deformities: Look for hammertoes, prominent metatarsal heads, bunions, pes planus, or other structural abnormalities that increase plantar pressure 1
• Examine for pre-ulcerative signs: Check for calluses, blisters, hemorrhage, thickened toenails, or fungal infections 1
• Document pain location: Distinguish between forefoot, midfoot, rearfoot, and heel pain, as management differs by location 1, 2

Diagnostic Imaging Approach

Begin with weight-bearing radiographs of the foot (anteroposterior, lateral, and oblique views) as these have 80-100% sensitivity for common structural causes and are the standard initial imaging modality. 1

• Reserve MRI, CT, or bone scans for cases where radiographs are unrevealing and clinical suspicion remains high 1
• Advanced imaging should not be ordered as first-line studies 1

Management Based on Underlying Condition

For Diabetic Patients with Neuropathic Plantar Pain

Without Active Ulceration (Prevention Focus)

Prescribe therapeutic footwear with demonstrated 30% plantar pressure relief compared to standard therapeutic shoes, and strongly instruct patients never to walk barefoot, in socks only, or in thin-soled slippers. 1

• Provide custom-made insoles or therapeutic shoes when foot deformities or pre-ulcerative signs are present 1
• Treat all pre-ulcerative signs immediately: remove calluses, protect/drain blisters, treat ingrown nails, and prescribe antifungal therapy for infections 1
• Implement integrated foot care with professional treatment every 1-3 months 1

With Active Neuropathic Plantar Forefoot or Midfoot Ulcers

Use a non-removable knee-high device (total contact cast or walker) with appropriate foot-device interface as first-line offloading treatment. 1

This recommendation is based on strong evidence showing superior healing rates with non-removable devices due to guaranteed adherence 1. The hierarchy of offloading interventions is:

1. First choice: Non-removable knee-high device (total contact cast or walker) 1
2. Second choice: Removable knee-high walker—only if non-removable device is contraindicated/not tolerated AND patient adherence is assured 1
3. Third choice: Forefoot offloading shoe, cast shoe, or custom temporary shoe—only when knee-high devices cannot be used 1
4. Do NOT use: Conventional or standard therapeutic shoes, as these will not heal plantar ulcers 1

Important caveat: If infection is present requiring frequent dressing changes, start with a removable device initially, then transition to non-removable once infection is controlled 1

Surgical Offloading When Conservative Treatment Fails

Consider Achilles tendon lengthening for recurrent plantar forefoot ulcers that fail conservative management, as this has moderate-quality evidence for promoting and sustaining healing. 1

Other surgical options with lower evidence quality include 1:

• Metatarsal head resection for plantar metatarsal head ulcers
• Joint arthroplasty for hallux ulcers
• Metatarsal osteotomy for ulcers on metatarsal heads 2-5
• Digital flexor tenotomy for plantar/apex ulcers on digits 2-5 with flexible toe deformity (strong recommendation with moderate evidence) 1

For Non-Diabetic Patients with Mechanical Plantar Pain

Plantar Fasciitis (Most Common Cause)

Initiate stretching exercises of the plantar fascia combined with foot orthotics as first-line therapy. 2

• Recognize that 44% of patients continue to have pain 15 years after diagnosis, so set realistic expectations 2
• Progress to extracorporeal shockwave therapy, corticosteroid injection, or platelet-rich plasma injection if first-line therapy fails 2
• Address gastrocnemius and hamstring tightness through stretching, as muscle tightness is a primary mechanical overload factor 3

Morton Neuroma (Forefoot Burning Pain)

Start with activity modification, orthotics, and interdigital corticosteroid injection. 2

• Expect approximately 30% of patients to not respond to conservative treatment and may require surgical intervention 2
• Pain typically localizes to the ball of the foot with radiation to third and fourth toes 2

For Patients with Peripheral Arterial Disease

Obtain ankle-brachial index testing in patients with symptoms or signs of PAD, and measure toe pressures (preferred over ankle pressures due to medial artery calcification in diabetics). 1

Critical thresholds requiring vascular intervention 1:

• Toe pressure <30 mmHg
• Ankle pressure <50 mmHg
• Transcutaneous oxygen pressure <25 mmHg

Urgent vascular imaging and revascularization should be pursued when these thresholds are met in patients with foot ulcers. 1

Critical Pitfalls to Avoid

• Never allow diabetic patients to walk barefoot or in inadequate footwear, even at home—this is a strong recommendation despite low-quality evidence due to high risk of ulceration 1
• Do not use removable offloading devices in non-adherent patients, as poor compliance negates their effectiveness 1
• Do not assume palpable pulses rule out PAD in diabetic patients—formal vascular testing is required 1
• Avoid nerve decompression procedures for ulcer prevention in diabetic patients, as evidence does not support this over standard care 1
• Do not order MRI or CT as initial imaging—radiographs must come first 1

Special Considerations

Chemotherapy-Related Palmar-Plantar Pain

If the patient has recent chemotherapy exposure (doxorubicin, cytarabine, docetaxel, fluorouracil, capecitabine), consider palmar-plantar erythrodysesthesia (hand-foot syndrome) 4, 5:

• Presents with painful erythema, paresthesia, and potentially blistering
• Management requires dose reduction or withdrawal of the offending agent
• Supportive care includes topical wound care, elevation, and cold compresses 4

Monitoring and Follow-Up

• Re-evaluate after 4 weeks if no improvement occurs with appropriate therapy, and consider alternative diagnoses 1
• For diabetic patients with ulcers, reassess perfusion if wound area does not significantly improve after 4 weeks of treatment 1
• Annual comprehensive foot examinations are mandatory for all diabetic patients, with more frequent assessments (every 1-3 months) for high-risk patients 1