Differential Diagnosis for a 48-year-old Female with Right Ankle Contusion
Single most likely diagnosis
- Ankle Sprain: This is the most common injury following an ankle contusion, especially with a negative X-ray. The pain and swelling are consistent with ligamentous injury.
Other Likely diagnoses
- Ankle Contusion/Bruise: Direct trauma to the ankle can cause soft tissue injury, leading to pain, swelling, and bruising without any fracture.
- Ligamentous Injury (not sprain): This could include injuries to the deltoid ligament or other ligaments around the ankle, which might not be as common as a sprain but still possible.
- Tendon Injury: Injuries to the tendons surrounding the ankle, such as the Achilles tendon or the peroneal tendons, could also present with pain and swelling.
Do Not Miss (ddxs that may not be likely, but would be deadly if missed)
- Compartment Syndrome: Although less common, compartment syndrome is a serious condition that can occur after an ankle injury, characterized by increased pressure within the muscle compartments, leading to severe pain, pallor, poikilothermia, paresthesia, and pulselessness.
- Osteochondral Fracture: Despite a negative initial X-ray, an osteochondral fracture (a fracture that involves the cartilage and bone) could be missed and might require further imaging like an MRI for diagnosis.
- Deep Vein Thrombosis (DVT): Immobility following an ankle injury could increase the risk of DVT, which is a potentially life-threatening condition if it leads to pulmonary embolism.
Rare diagnoses
- Stress Fracture: While less likely in the acute setting of a contusion, stress fractures could be considered if the pain persists and other diagnoses are ruled out, especially in individuals with risk factors such as osteoporosis or excessive physical activity.
- Neuropraxia or Nerve Injury: Direct trauma to the nerves around the ankle could result in neuropraxia or more severe nerve injuries, presenting with numbness, tingling, or weakness.
- Infection (e.g., Cellulitis or Abscess): If the skin is broken, there's a risk of infection, which would present with signs of inflammation (redness, warmth, swelling) and possibly fever.