How Can Lumbar Spondylosis With Nerve Pains Be Treated?

My wife aged 65 years is suffering since last ten months from acute nerve pain in buttocks and legs upto heels.As per advice of the neurosurgeon MRI and Digital X-Rays of the lumbar region were done.It was diagnosed that she is suffering from lumber spondylosis(grade one listhesis of L4 overL5).Since she is not getting any relief (she was prescribed maxgalin-m 75 tablets for a few months) even after medication,the doctor has advised for a surgery which she is reluctant to go for,due to various risks involved.Please advise for other options to get rid of the severe nerve pains she is undergoing now.