Hi and welcome to HCM.
Well, this is all aprt of aging and caused by degenerative bone changes. These white spots
can be sign of osteoporosis
or spondilitis and it can cause lumbal pain and pain in legs. If you a re afraid of malignant lesinos this is unlikely in such findings. In the beginning this is terated by exercises and medical therapy, but if thisisnt helpful then surgical therapy should be considered.Wish you good health.