In 30% of cases the patient feels immediate improvement of pain that then improves further and gradually in the following 4 to 6 weeks. In 70% of cases often there are “up and down pain” with “old” and “new” pain in the following 4 – 6 weeks and a serious and reliable judgment on the success of pldd is given only after 6 weeks. When the success is positive, the improvements can continue up to 11 months after the procedure.