Hi Bronco.
I had nerve blocks which were unsuccessful for the condition in my knee. Lignocaine (lidocaine in U.S.) & Guanethidine. The doctor doing them was unable to get a vein and the cuff (like the one for measuring B.P.) would not fit my leg - my quads had not wasted so much at that time also veins collapsed etc. I put lack of success down to poor technique.

As a diagnostic tool my research indicates that blocks are not all that decisive but they can be extremely helpful for some in the relief from pain - the time since onset appears to be a factor in success - apparently, the shorter that time, the better.

From a personal perspective, after 5 years I would still consider neuroablation if I were able to find someone profficient in radiofrequency ablation who would use live filming techniques (x-rays)to address specific neurons.

I am only just starting to consider this as I have tried Spinal column Stimulation (a complete flop).

I have had recent discussions with a doctor (who is not an expert in pain management) that lead me to believe that the longer the condition is established, the less efficacious the technique and the pain can learn new pathways - but I understand that this means more very careful neuroablation.

The technique of ablation appears to matter ; thus chemical and thermal interruption of neural pathways can be a bit general and hence problematic but I understand radio-frequency techniques can be clean and decisive (hopefully). There are other techniques but I am only just starting to head in that direction so my knowledge is a bit shallow.

Best of luck with the procedure.

Best regards Auberon