Differential Diagnosis for 85-year-old with Leg Pain after Fall

Single Most Likely Diagnosis

• Intertrochanteric hip fracture: This is the most likely diagnosis given the patient's age, mechanism of injury (fall onto the right leg), and the specific detail that pain is aggravated when she steps forward with her left leg and takes pressure off the right leg. This action would increase the stress on the hip, exacerbating the pain if a fracture is present.

Other Likely Diagnoses

• Femoral neck fracture: Similar to an intertrochanteric hip fracture, a femoral neck fracture could occur from a fall and would cause significant pain, especially with weight-bearing activities.
• Pelvic fracture: Given the mechanism of injury, a pelvic fracture is also a possibility, especially in an elderly patient with potentially weakened bones.
• Soft tissue injury (contusion, hematoma): While less severe than a fracture, a significant soft tissue injury could result from the fall and cause considerable pain.

Do Not Miss Diagnoses

• Abdominal or retroperitoneal hemorrhage: Although less common, a fall could potentially cause internal injuries leading to bleeding. This would be particularly concerning in an elderly patient who might be on anticoagulants or have other comorbidities.
• Vascular injury: Damage to the femoral artery or vein could occur from a fracture or severe soft tissue injury, leading to complications like ischemia or significant blood loss.

Rare Diagnoses

• Stress fracture: While possible, stress fractures are less likely given the acute nature of the injury from a fall.
• Pathological fracture: If the patient has an underlying bone disease (e.g., metastatic cancer, osteomyelitis), a pathological fracture could occur with minimal trauma.
• Nerve injury: Direct trauma to nerves in the leg could result from the fall, but this would typically present with neurological deficits rather than pain as the primary symptom.