Need expert help here. what are the risks involved with back surgery?

Depends on type: The risks of back surgery depends on the type and the indications. For the routine decompression of a nerve root for a herniated disc, the risks are low but include pain, recurrent disc, infection, paralysis, cerebrospinal fluid leakage. As the surgery becomes more complex and includes fusions with rods and screws, the risks increase.

Varies: In general, spinal surgery is safe with relatively low complication rate. Complications can be spine and surgery related or related to anesthesia and perioperative medical complications. Each specific spinal surgery, such as in a thoracic disc herniation which you are describing, has it's own unique risks and benefits and so you should certainly have a good talk with your surgeon. Thank you.