What is the reason for my intense and burning pain down the thigh even after spinal fusion surgery?

Hi doctor,

I had L4-L5, and L5-S1 fused six years back and had right sacroiliac joint fusion four years ago. But, the pain persisted. I also had labral tear repair, gluteus medius and minimus, and bursectomy two years back, and still, the pain persisted. Now, five weeks post revision surgery of previous fusion and clean up of sacroiliac joint as was very unstable and re-fused. Unfortunately, I also have intense pain in my thigh that gives a burning sensation all down the back of my thigh and sides. The nerves are in spasm, and I can follow the nerves with my finger. I am using ice packs. No pain killers took the pain away. I did have this pain before surgery, but it is way worse. My surgeon suggested getting a CT scan of the pelvis done. I asked whether they could scan the thigh, too, as the pain is radiating from the area where the thigh joins the pelvis, the ischial tuberosity area. But my surgeon said it is not needed. Another scan says I have hamstring tendinopathy. My surgeon did say that one of the screws is quite near the sciatic nerve. The pain is pulsating, throbbing, and burning. What could be causing this? Currently, I am taking Xarelto 10 mg, Targin 5 mg, Palexia 100 mg, and Gabapentin 300 mg. Kindly help.

Hi doctor,

Thank you for the reply.

So apparently, my CT scan showed that all fixations and screws from the surgery are fine. Are there other radiology tests to be done? I cannot sit or lie, and the pain is very severe, like bone and nerve entrapment in that whole area where the leg or hip attaches to the pelvis and in the lower buttock area. It is swollen and warm to the touch. As I mentioned, I have had this type of pain for well over a year, but it has been worsening and way more severe since I had surgery. Are there other scans that would show this area better? The pain is burning, throbbing, pulsating, and unbearable, and it is severe on the proximal thigh. After three days, my surgeon suggested getting admitted for pain management and some investigations. I would like to know more information about the structures I mentioned to you. Does the ischial tuberosity be seen on a CT of the pelvis? I feel the pain is radiating from there too. Kindly help.

Hi doctor,

Thank you for the information.

Today, my surgeon took blood to check inflammatory levels, etc. (all normal, I think, ESR a bit increased). He suggested a diagnostic injection into hamstrings. I was delighted as the injection cooled down most of the area, and the pain went off. But three hours later, the pain returned, so I was upset. The pain is the worst that I ever felt. I know that it is hard to understand what is causing the pain with all the muscles, tendons, and nerves. I would like to know, is the ischial tuberosity visualized on a CT scan? Is the fact it cooled and reduced pain for three hours a sign that something is wrong with the hamstring area? What are the other tests to be done? Could it be a tear or impingement? Would ultrasound and nerve conduction studies do anything? Kindly help.