Differential Diagnosis for Lateral Ankle Pain
Single Most Likely Diagnosis
- Ankle Sprain: This is the most common cause of lateral ankle pain, typically resulting from inversion injuries that stretch or tear the ligaments on the outside of the ankle. The mechanism of injury and the location of pain and swelling usually point towards this diagnosis.
Other Likely Diagnoses
- Peroneal Tendinopathy: Inflammation or degeneration of the peroneal tendons, which run along the lateral aspect of the ankle, can cause pain in this area. Overuse or repetitive ankle motion is a common cause.
- Lateral Ankle Impingement: This condition involves soft tissue impingement in the lateral gutter of the ankle, often due to chronic ankle instability or previous ankle sprains, leading to pain and limited mobility.
- Osteochondral Lesion of the Talus: A condition where a piece of cartilage and bone in the talus (ankle bone) becomes damaged, often due to trauma. It can cause lateral ankle pain, especially with weight-bearing activities.
Do Not Miss Diagnoses
- Fracture (e.g., Fibula or Talus): While less common than sprains, fractures can occur with significant trauma and must be ruled out to avoid missing a potentially serious condition that requires immediate intervention.
- Osteomyelitis or Septic Arthritis: Infection within the bone or joint, respectively, which can present with pain, swelling, and redness. These conditions are medical emergencies requiring prompt diagnosis and treatment.
- Compartment Syndrome: A condition where increased pressure within a muscle compartment leads to inadequate blood supply to the tissues inside the compartment. It's a rare but serious condition that can result from severe injury or reperfusion after ischemia.
Rare Diagnoses
- Ganglion Cyst: A lump under the skin that occurs when fluid accumulates, potentially causing pain if it presses on nearby nerves or joints.
- Nerve Entrapment (e.g., Superficial Peroneal Nerve): Compression or irritation of the nerves around the ankle can cause pain, numbness, or tingling in specific areas of the foot or ankle.
- Tumors (Benign or Malignant): Although extremely rare, tumors can cause lateral ankle pain if they develop in the bones, tendons, or soft tissues around the ankle.