Differential Diagnosis for Left Foot Dorsal Pain
Single Most Likely Diagnosis
- Morton's Neuroma: This condition is characterized by sharp pain in the plantar aspect of the foot, typically between the 3rd and 4th metatarsals, but can also occur between other metatarsals. The pain is often exacerbated by weight-bearing activities. Although the ultrasound was negative, Morton's neuroma can be difficult to visualize on ultrasound, and clinical presentation is key to diagnosis.
Other Likely Diagnoses
- Stress Fracture: Despite the lack of findings on X-ray, stress fractures, especially of the metatarsals, can be occult and not visible on initial X-rays. The dorsal soft tissue swelling could be indicative of a stress reaction or fracture.
- Metatarsalgia: This condition involves pain and inflammation in the metatarsal region, often due to overuse or poor foot mechanics. It could explain the dorsal pain over the mid 3rd metatarsal and sharp plantar pain during weight-bearing.
- Capsulitis or Bursitis of the Metatarsophalangeal Joint: Inflammation of the joint capsule or bursae around the metatarsophalangeal joints can cause pain, especially during weight-bearing activities.
Do Not Miss Diagnoses
- Osteomyelitis or Septic Arthritis: Although less likely, infections such as osteomyelitis (bone infection) or septic arthritis (joint infection) are critical to rule out due to their potential for serious complications. The presence of dorsal soft tissue swelling and pain could be indicative of an infectious process.
- Tumor (Benign or Malignant): Although rare, tumors of the foot, including the metatarsal bones, can present with pain and swelling. It's essential to consider this possibility to ensure timely diagnosis and treatment.
Rare Diagnoses
- Freiberg's Disease: A rare condition characterized by avascular necrosis of the metatarsal head, typically affecting the 2nd metatarsal but can involve others. It presents with pain and can mimic other conditions.
- Kohler's Disease: A rare bone disorder causing pain and swelling in the foot, typically affecting the navicular bone in children, but could be considered in the differential for midfoot pain in adults as well.