What is the diagnosis and treatment for an overweight patient complaining of intermittent pain on top of the left foot?

Dorsal Foot Pain in an Overweight Patient: Diagnosis and Management

Most Likely Diagnosis

The most likely diagnosis is extensor tendonitis, which presents as intermittent pain on the dorsum (top) of the foot and is significantly more common in overweight patients due to increased mechanical stress on soft tissues. 1, 2

Differential Diagnoses to Consider

Primary Musculoskeletal Causes

• Extensor tendonitis: Pain worsens with active toe extension or resisted dorsiflexion, with point tenderness localizing along the extensor tendons running across the dorsal surface 1
• Metatarsal stress fracture: Common in individuals with increased weight-bearing stress; initial radiographs detect only 12-56% of stress fractures, so negative x-rays don't exclude this diagnosis 1
• Midfoot osteoarthritis: Pain worsens with weight-bearing and dorsiflexion, particularly affecting tarsometatarsal or midtarsal joints 1

Key Clinical Point

Overweight and obese patients (BMI ≥25) have significantly increased likelihood of tendinitis in general, and increased (though not statistically significant) likelihood of plantar fasciitis and osteoarthritis compared to normal-weight individuals 2. Fat mass itself—not just total body weight—is an independent predictor of incident foot pain, with each unit increase in fat mass index increasing odds of foot pain by 28% 3.

Diagnostic Workup

Initial Imaging

Obtain weight-bearing radiographs of the foot as the first imaging study for all patients with dorsal foot pain. 1 This is the standard initial approach regardless of clinical suspicion.

If Radiographs Are Negative But Pain Persists >1 Week

• MRI without contrast or CT without contrast are equivalent alternatives for detecting stress fractures and soft tissue pathology 1
• Three-phase bone scan has 100% sensitivity and negative predictive value for ruling out stress fractures when radiographs are negative 1

Critical Pitfall

Do not rely solely on initial radiographs to exclude stress fractures, given their poor sensitivity of only 12-56% 1. If clinical suspicion remains high despite negative x-rays, proceed directly to advanced imaging.

Treatment Algorithm

Phase 1: Conservative Management (Initial 6-8 Weeks)

For Extensor Tendonitis (Most Likely):

• Rest and activity modification: Reduce activities that worsen pain but avoid complete immobilization to prevent muscle atrophy 4
• NSAIDs (oral or topical) for pain relief and inflammation reduction 4
• Ice therapy through a wet towel for 10-minute periods 4
• Proper footwear with adequate cushioning and arch support 4
• Stretching exercises 3-5 times daily for affected tendons 4

Critical Warning: Avoid corticosteroid injections near extensor tendons due to risk of tendon rupture 1

Phase 2: Weight Management Integration

Combining weight reduction with conservative pain management is more effective than either intervention alone for reducing pain and disability in overweight patients with musculoskeletal pain 5.

• Overweight adults are 14-71% more likely to report chronic pain than normal-weight adults 6
• Regular exercise (aerobic, resistance, or multimodal) can reduce joint pain by 14-71.4% in obese adults 7
• Weight loss reduces mechanical loading, systemic inflammation, and biomechanical stress on foot structures 5

Phase 3: Advanced Treatment (If No Improvement After 6-8 Weeks)

Refer to a podiatric foot and ankle surgeon if no improvement occurs within 6-8 weeks of appropriate conservative treatment 4

Additional options include:

• Custom orthotic devices 4
• Immobilization with cast or fixed-ankle walker if stress fracture confirmed 4
• Extracorporeal shock wave therapy for persistent pain 4

Key Clinical Pearls

Examination Findings to Document

• Point tenderness location along extensor tendons 1
• Pain with active toe extension or resisted dorsiflexion 1
• Presence of swelling or erythema 1
• Gait pattern and weight-bearing tolerance 1

Mechanical Factors in Obesity

The relationship between obesity and foot pain is driven by increased biomechanical load, low-grade inflammation, and changes in pain processing 5. This explains why tendinitis, plantar fasciitis, and osteoarthritis—all overuse conditions—are more common in overweight individuals 2.

When to Escalate Care Immediately

Seek immediate evaluation if pain becomes constant at rest, or if numbness or increasing swelling/redness develops, to rule out infection or nerve compression 4.