Hi, thanks for writing to HCM. I suspect that the most possible cause in your case is complex regional pain syndrome which commonly develops after an injury or surgery in the leg. There is no single test to confirm the diagnosis of this condition. A series of investigations like Bone scan, xrays, MRI and few nervous system tests are necessary to confirm the diagnosis. A detailed clinical examination by your family physician is necessary to establish the correct diagnosis and further management. Hope this information is helpful. Good day