Are you a smoker?
Were any investigations like colored Doppler or MRI done?
Saddle block anesthesia thirty years ago does not seems to be related with your problem. The problems you are experiencing seems to be because of spinal canal stenosis. Read the details here;
Another possibility is degenerative disk disease. Read the details and treatment options here;
Diagnosis of both the conditions is by MRI. The specialist concerned is physiatrist (MD in physical medicine and rehabilitation). A lumbosacral corset and physical therapy is one of the best treatment option with back care in the activities of daily living.