Differential Diagnosis for Nonunited Scaphoid Waist Fracture with Avascular Necrosis

• Single most likely diagnosis
  • Scaphoid nonunion with avascular necrosis: This is the most direct diagnosis based on the given information, as it directly matches the description provided. The scaphoid bone's unique blood supply, which enters from the distal end, makes the proximal pole more susceptible to avascular necrosis when a fracture occurs, especially at the waist.
• Other Likely diagnoses
  • Scaphoid fracture with proximal pole osteonecrosis: Similar to the most likely diagnosis but focuses on the osteonecrosis aspect, which is a common complication of scaphoid fractures due to the compromised blood supply.
  • Preiser's disease: A condition of avascular necrosis of the scaphoid bone not due to trauma, which could present similarly to a nonunited fracture with avascular necrosis if the history of trauma is not clear.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Infection (osteomyelitis): Although less likely, infection of the bone could present with similar symptoms and would require urgent treatment to prevent serious complications.
  • Malignancy (e.g., osteosarcoma, chondrosarcoma): Rarely, a tumor could mimic the appearance of a nonunited fracture with necrosis, and missing this diagnosis could have severe consequences.
• Rare diagnoses
  • Kienböck's disease: A rare condition of avascular necrosis of the lunate bone, which, while different, could be considered in the differential for wrist pain and avascular necrosis, though it does not directly match the description of a scaphoid waist fracture.
  • Kohler's disease: A rare condition affecting the navicular bone in children, characterized by avascular necrosis, which is not directly relevant but could be considered in a broad differential for wrist pain in younger patients.