Differential Diagnosis: Bone Pain and Fractures

Bone pain is a very common feature of many metabolic bone diseases, including metastatic bone disease, osteoporosis, and Paget’s disease of bone. The mechanism of pain is complex and depends on an increasing number of interrelated pathways and mediators. In general terms, bone pain can be categorized as arising from one a direct action on bone nociceptors or from a secondary mechanical effect. There is little evidence that bone loss itself causes symptoms until a fracture occurs. Therefore, in osteoporosis all the clinical manifestations are a direct or indirect consequence of fracture, and thus bone pain is the main clinical symptom. The most common causes of true bone pain, as opposed to joint pain, are trauma, osteoporosis, and malignancy. Distinguishing between these different causes can be difficult, and some diagnoses are often made only after exclusion of all other diseases. Pain due to acute vertebral fracture can be extremely severe and therefore difficult to manage. In the initial management, the aim is to reduce the level of discomfort and improve mobility as soon as possible. Immobilization should be avoided, since prolonged immobilization is associated with further bone loss. Simple analgesics are sometimes sufficient to alleviate the pain. In patients for whom simple analgesics do not provide adequate pain relief, NSAIDs or narcotic analgesics may be necessary. To date, a large number of clinical studies have shown that either salmon calcitonin or bisphosphonates (clodronate and pamidronate given parenterally) are effective in the management of acute stages of acute vertebral collapse. Both of these treatments are able to determine a significant shortening of the painful phase in osteoporotic patients, favoring a good and rapid recovery.