Differential Diagnosis

• Single most likely diagnosis
  • Medial ankle sprain: The widening of the medial tibial talar joint and the nonspecific increased density inferior to the medial malleolus are consistent with a medial ankle sprain, which is a common injury that can cause these radiographic findings.
• Other Likely diagnoses
  • Medial ankle impaction injury: This could also explain the increased density and joint widening due to bone bruising or impaction.
  • Soft tissue injury (e.g., tendon or ligament injury): The increased density could represent soft tissue swelling or hematoma related to a tendon or ligament injury around the medial ankle.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Osteonecrosis of the talus: Although less common, osteonecrosis could present with increased density due to sclerosis and joint widening due to collapse, and missing this diagnosis could lead to significant morbidity.
  • Infection (e.g., osteomyelitis or septic arthritis): Increased density and joint widening could also be signs of an infectious process, which would require urgent medical attention.
• Rare diagnoses
  • Bone tumor (e.g., osteoid osteoma): A rare possibility for the increased density, although typically, these would have more characteristic radiographic features.
  • Pigmented villonodular synovitis (PVNS): A rare condition that could cause joint widening and increased density due to synovial proliferation, but it would be an uncommon diagnosis in this context.