Differential Diagnoses for Sole of Foot Pain

Anatomic Localization-Based Differentials

The American College of Radiology suggests that plantar fasciitis, stress fractures, nerve entrapment, soft tissue masses, sesamoid pathology, and metatarsal disorders should be included in a comprehensive differential diagnosis for sole of foot pain based on precise pain localization 1, 2
Tarsal coalition should be suspected in chronic midfoot pain, with radiographs showing 80-100% sensitivity for calcaneonavicular coalitions and 100% sensitivity for talocalcaneal coalitions 1, 4
Metatarsal stress fractures, particularly second and third metatarsals, are common in runners and athletes 1
Morton's neuroma causes webspace pain between metatarsal heads, though radiographs are insensitive but useful to exclude other pathology 1
Sesamoid disorders, such as sesamoiditis, fracture, or bipartite sesamoid, affect the first metatarsal head region 1
Freiberg's infraction, an osteochondrosis of the metatarsal head, typically affects the second metatarsal 1
Cuboid syndrome or lateral column stress fractures can cause lateral plantar pain 2

Soft tissue infection presents with non-purulent secretions, friable granulation tissue, wound undermining, and foul odor, and is a common complication in diabetic patients 5, 6
Osteomyelitis underlying diabetic foot ulcers carries high amputation risk and requires prompt diagnosis, according to the European Journal of Nuclear Medicine and Molecular Imaging 5, 6
Charcot foot is an inflammatory, destructive disorder mainly involving tarsal and metatarsal joints that may coexist with or cause ulcers in diabetic patients 5, 6
Inflammatory arthropathies should be considered with bilateral symptoms or pain in other joints 2

Weight-bearing radiographs of the foot are the first imaging study for chronic foot pain, useful for tarsal coalitions, fractures, sesamoid pathology, and Freiberg's infraction, as recommended by the Journal of the American College of Radiology 1, 4, 3
Radiographs show thickened plantar fascia and fat pad abnormalities with 85% sensitivity and 95% specificity for plantar fasciitis 1
MRI without contrast is recommended if radiographs are negative but pain persists >1 week, or for suspected stress fractures, Morton's neuroma, or soft tissue pathology 1, 3
Technetium bone scanning is useful for suspected stress fracture with negative radiographs, as symptoms precede radiographic findings 2

The International Working Group on the Diabetic Foot and the Infectious Diseases Society of America recommend obtaining plain radiographs first in diabetic patients before advanced imaging 5, 6
The American College of Radiology advises against relying solely on initial radiographs to exclude stress fractures given 12-56% sensitivity 1, 2
The European Journal of Nuclear Medicine and Molecular Imaging warns against injecting corticosteroids near the Achilles tendon due to rupture risk 2, 7