Brief Answer:
rather a lot of possibilities.....

Detailed Answer:
Generally if back problems are going to radiate along the path of the nerve down the side of the hip and down the (back of) the leg, then there will also be a lot of back pain. This can be from the previous disk, the surgery having problems, or even a new problem causing the back pain. Cancer can cause the back to collapse and cause acute pain and paralysis! Or.. just thin bones and old age without cancer can do the same thing. These are emergencies and if not treated immediately will lead to permanent neurological damage and inability to ever walk again. (I think XXXXXXX H Bush had this happen).

Or, it can be degeneration of joints. This is not generally an immediate emergency AND will need attention to be able to move normally.

Basically, if someone cannot walk, it's an emergency and they need immediate attention.

---

Brief Answer:
cannot say on it...

Detailed Answer:
First, a regular doctor should be able to do everything for the evaluation for this.
While an orthopedist is specialized in bone/joint and pain management is specialized for more advanced methods... neither is as well set up for just saying what is going on as a regular doctor (family, general, maybe internist).

Then.... rest, icy-hot, aleve is a general treatment but isn't going to be right for MOST situations (won't work on disk, hip fracture, bone collapse; not best for joint problems).

---