Differential Diagnosis for Severe Right Metatarsal Pain Preventing Walking

Primary Differential Diagnoses

Stress fracture is a leading cause of severe metatarsal pain that prevents walking, though initial radiographs have limited sensitivity (12-56%) and may appear normal early in the course, according to the American College of Radiology 1
Acute fracture of the fifth metatarsal base is particularly common given the prominent tuberosity at this location 2
Freiberg's infraction (osteochondrosis of the metatarsal head, typically second metatarsal) should be considered, especially in adolescents, as recommended by the American College of Radiology 1
Intermetatarsal bursitis can mimic neuroma symptoms, as noted by the American College of Radiology 1
Osteoarthritis of the metatarsophalangeal (MTP) joints can cause severe pain, particularly at the first MTP joint, according to the American College of Radiology 1
Sesamoiditis or sesamoid fracture at the first metatarsal should be considered if pain is localized to the great toe, as recommended by the American College of Radiology 1

Order weight-bearing plain radiographs of the foot (not ankle) as the first-line imaging study, including lateral and oblique views, as recommended by the American College of Radiology 1 and Praxis Medical Insights 4
Radiographs can identify fractures, dislocations, osteoarthritis, and bony deformities with good specificity (88-96% for stress fractures), according to the American College of Radiology 1
The Ottawa Ankle Rules should guide whether radiographs are needed: obtain x-rays if there is palpation pain at the base of the fifth metatarsal or navicular bone, or inability to bear weight for four steps, as recommended by the British Journal of Sports Medicine 5 and Praxis Medical Insights 2
Weight-bearing views are essential for proper evaluation of foot structures and pressure distribution, as noted by the American College of Radiology 1 and Praxis Medical Insights 4

If radiographs are negative but clinical suspicion remains high for stress fracture or soft tissue pathology, proceed directly to MRI of the foot without contrast, as recommended by the American College of Radiology 1 and Praxis Medical Insights 3 and 4
MRI has high sensitivity (87-93%) and specificity (68-100%) for Morton's neuroma, according to Praxis Medical Insights 3
MRI is superior to ultrasound for detecting plantar plate tears, as noted by Praxis Medical Insights 3
MRI is the examination of choice for occult stress fractures and subchondral injury, as recommended by Praxis Medical Insights 4
Ultrasound can be used as an alternative for Morton's neuroma (sensitivity 83-96%) but is operator-dependent, according to Praxis Medical Insights 3

Activity level: high-level athletic activity increases risk of stress fracture, as noted by the American College of Radiology 1
Footwear: tight or high-heeled shoes predispose to Morton's neuroma, according to Praxis Medical Insights 3
Palpation: point tenderness over metatarsal shaft suggests fracture; tenderness in webspace suggests neuroma, as recommended by the American College of Radiology 1
Weight-bearing ability: complete inability to bear weight suggests fracture or severe soft tissue injury, as noted by the British Journal of Sports Medicine 5
Mulder's click: palpable click with compression of metatarsal heads suggests Morton's neuroma, according to Praxis Medical Insights 3

Do not rely solely on initial radiographs for stress fractures—they miss 44-88% of cases early in the course; proceed to MRI if clinical suspicion is high, as recommended by the American College of Radiology 1 and Praxis Medical Insights 4
Do not order ankle radiographs for metatarsal pain—they will not properly visualize the metatarsals or MTP joints, as noted by Praxis Medical Insights 4
Do not miss infection in diabetic or immunocompromised patients—these patients require urgent evaluation and may need surgical intervention, according to Praxis Medical Insights 3