Differential Diagnosis for Ankle and Shin Pain

The patient presents with a history of a recent fall while running, followed by severe pain in the left ankle and shin, swelling with minimal use, and persistent discomfort. Considering these symptoms, the following differential diagnoses are possible:

• Single most likely diagnosis
  • Medial tibial stress syndrome (Shin splints): This condition is common in runners and is characterized by pain and swelling in the shin area, often due to overuse or repetitive stress on the muscles and bones. The patient's history of continuing to run after the initial fall and the subsequent severe pain and swelling are consistent with this diagnosis.
• Other Likely diagnoses
  • Ankle sprain: Although the patient mentions pain in the shin, an ankle sprain could also cause referred pain and swelling in the surrounding areas, including the shin.
  • Stress fracture: A stress fracture, particularly in the tibia or fibula, could result from repetitive stress and overuse, consistent with the patient's running activities.
  • Periostitis: Inflammation of the periosteum, a layer of tissue surrounding the bones, could cause pain and swelling, especially if the patient has been running on a potentially injured ankle.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Compartment syndrome: Although less likely, compartment syndrome is a serious condition that requires immediate medical attention. It involves increased pressure within the muscle compartments, which can lead to nerve and muscle damage.
  • Deep vein thrombosis (DVT): DVT is a blood clot in the deep veins, typically in the legs. While less common in this scenario, it's a critical condition to rule out due to the risk of pulmonary embolism.
• Rare diagnoses
  • Osteomyelitis: A bone infection that could cause pain, swelling, and redness, although it would typically be accompanied by other systemic symptoms such as fever.
  • Tumor: A bone tumor, either benign or malignant, could cause localized pain and swelling, but this would be an uncommon presentation without other symptoms or risk factors.

Given the patient's symptoms and history, an office visit is the best path forward to evaluate the ankle and shin, potentially including imaging studies to rule out more serious conditions and to guide appropriate treatment.