I am a doctor and have regional migratory osteoporosis. My bone density is normal - apart from the affected areas. Looking through the literature, there is anecdotal evidence that biphosphonates may help. I have been taking oral treatment in the hope of preventing further attacks, but currently suspect this has not worked (one knee is beginning to stiffen again). I think the problem here is the name of the condition - it is NOT systemic osteoporosis, but a disease of unknown aetiology (possibly neurological which causes focal inflammation with secondary focal areas of reduced bone density.