Differential Diagnosis for Stabbing Pain outside Left Ankle/Achilles
Single most likely diagnosis
- Peroneal Tendinopathy: This condition is characterized by inflammation of the peroneal tendons, which run along the outside of the ankle. Bending at the hip around 75 degrees can cause the peroneal tendons to rub against the lateral malleolus, triggering pain. The location and mechanism of pain suggest peroneal tendinopathy as a likely diagnosis.
Other Likely diagnoses
- Achilles Tendinopathy: Although the pain is described as being outside the Achilles, some cases of Achilles tendinopathy can refer pain to the lateral aspect of the ankle. The mechanism of bending at the hip could exacerbate Achilles tendinopathy, especially if it involves tight calf muscles.
- Lateral Ankle Impingement: This condition occurs when there is compression of the soft tissues (including tendons and ligaments) on the outside of the ankle. Hip flexion can indirectly cause lateral ankle impingement, leading to stabbing pain in the area.
- Peroneal Tenosynovitis: Inflammation of the tendon sheath surrounding the peroneal tendons can cause pain on the outside of the ankle, which might be exacerbated by movements that increase tension on these tendons, such as hip flexion.
Do Not Miss diagnoses
- Deep Vein Thrombosis (DVT): Although less common, DVT can present with pain in the ankle or leg, especially if the clot is located in the lower extremities. The pain might be exacerbated by movements that increase venous pressure, such as bending at the hip. Missing a DVT could be catastrophic due to the risk of pulmonary embolism.
- Osteonecrosis of the Talus or Calcaneus: This condition involves the death of bone tissue due to a lack of blood supply. It can cause severe pain around the ankle, which might be triggered by specific movements. Early diagnosis is crucial to prevent further bone collapse and potential need for surgical intervention.
Rare diagnoses
- Tarsal Tunnel Syndrome: This is a rare condition that involves compression of the posterior tibial nerve as it travels through the tarsal tunnel on the inside of the ankle. However, in some cases, it might refer pain to the outside of the ankle. The mechanism of pain would be less directly related to hip flexion but could involve any movement that increases pressure on the nerve.
- Stress Fracture of the Fibula or Calcaneus: Stress fractures are small cracks in the bone that can occur due to repetitive stress or overuse. They are less likely to be directly triggered by hip flexion but could cause pain in the ankle area that worsens with activity.