Differential Diagnosis for Right Lateral Ankle Pain
Single Most Likely Diagnosis
- Ankle Sprain: This is the most common cause of lateral ankle pain, especially given the patient's ability to walk and the absence of a fracture on X-rays. The swelling and tenderness are consistent with a sprain, which typically occurs due to inversion of the ankle.
Other Likely Diagnoses
- Peroneal Tendinitis: Inflammation of the peroneal tendons, which run along the lateral aspect of the ankle, can cause pain and swelling in this area. This condition is often related to overuse or repetitive ankle motion.
- Lateral Ankle Impingement: This condition involves soft tissue impingement in the lateral gutter of the ankle, leading to pain and swelling. It can be due to various causes, including previous ankle sprains or fractures.
- Sinus Tarsi Syndrome: This condition affects the sinus tarsi, a small canal on the outer aspect of the ankle, and can cause lateral ankle pain due to inflammation or irritation of the structures within this canal.
Do Not Miss Diagnoses
- Osteochondral Lesion of the Talus: Although less common, an osteochondral lesion (a piece of cartilage and bone that has been damaged) can cause persistent ankle pain. It's crucial to consider this diagnosis because it may require specific treatment, including possible surgery.
- Infection (e.g., Cellulitis or Abscess): While less likely given the chronic nature of the pain, infection should always be considered, especially if there are signs of increased redness, warmth, or fever.
- Tumor: Although rare, a tumor (benign or malignant) in the ankle region could cause persistent pain and swelling. It's essential to keep this in the differential to ensure timely diagnosis and treatment if present.
Rare Diagnoses
- Ganglion Cyst: A benign lump that can occur on the lateral aspect of the ankle, causing pain and swelling.
- Nerve Entrapment (e.g., Superficial Peroneal Nerve Entrapment): This involves compression of a nerve, leading to pain, numbness, or tingling in the area supplied by the nerve.
- Stress Fracture Not Visible on Initial X-rays: Some stress fractures may not be apparent on initial X-rays and could become visible on follow-up X-rays or other imaging studies like an MRI.