Folks, I've opted for the less intrusive option and going to have an attempt at getting the 2nd lead threaded in with hope it will give more coverage. It's definitely the better option, the other being a fusion which will leave me with one only flexible disc and at high risk of further deterioration. Yay yay yay, I can't tell you how relieved I am that the option for a 2nd attempt at threading the 2nd lead in is available. Will find out in a few weeks when that will be happen. Feeling relieved and happy today