Brief Answer:
several things....

Detailed Answer:
I think we are both concened that that fall could have "knocked something loose". 8 weeks is generall enough time for healing, but at age 80 and with quite major surgery this might not be the case and significant damage may have occurred. Diagnosis of whether a serious problem has occurred would be the first question. You KNOW there is a severe problem if there are new neurological problems (weakness, inability to use bowel or bladder, loss of sensation). Another MRI is generally the best test but if metal was placed into the area, this makes an MRI impossible and various x rays (cat scans, probably with dye) are the only tests that can be done. If something has fallen apart and/or if there is new neurological damage you probably will need more surgery.

Assuming the best--there is no damage--what could be done for the pain. If it is not seriously broken surgery is not a good idea. Again it depends on the cause of the pain. a hip fracture can occur and someone not be aware of it. at weeks after the injury, if it were a hip fracture, some healing would have occurred and this can complicate the problem and might require complicated surgery to correct it and put the bones back into alignment. THEN convalescence, physical therapy, will have everything work better.

The most likely problems are not as serious and do not require surgery. There is the muscle. There could be just a groin pull. Rest, aspirin like drugs prescribed CAREFULLY because they have a lot of side effects, and then gradual physical therapy will work, but groin pulls last months. Lumbar disk disease is painful. But the pain type, location, and triggers are very different from the groin pull. The pain is with moving the leg straight out, and the pain is typically in the back of the leg. pressing on areas does not hurt in lumbar disk and does in a muscle disorder like a groin pull. There isn't much that can be done for lumbar disk disease other than finding what motions and activities to avoid. What can be done for lumbar disk disease needs prescription. Some of the safest mediines for lumbar disk disease pain are nerve pills. Anti-epileptics lower nerve pain (gabapentin and lyrica). Ones that damp down spinal transmission of pain (methacarbamol or cymbalta or amitryptiline) also are helpful but all of these are prescription (non-narcotic) medications for pain.

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