Causes of pain in degenerative bone and joint disease: a lesson from vertebroplasty

Pain in degenerative bone and joint disease is usually attributed to sensitized nociceptors in inflamed periarticular soft tissues. Here we draw attention to the potential contribution of intrinsic bone innervation. The structure and innervation of articular bone ends is analogous to that of teeth. Although some dental pain derives from inflamed periodontal soft tissue, a more important source is the dentine and root canal. By analogy, pain on weight bearing in osteoarthritis and related conditions may be due to compressive forces applied to the innervation of subchondral bone exposed by erosion of the overlying cartilage. Pain relief obtained by injecting acrylic cement into the bone interior during percutaneous vertebroplasty is consistent with this concept. The development of a new family of pain relief options based on "marrow canal treatment" may be a realistic possibility.