Paget's Disease of the spine and its management

A review of the literature was conducted to study the pathomechanics by whi ch Paget's Disease of bone (PD) alters the spinal structures that result in distinct spinal pathologic entities such as pagetic spinal arthritis, spin al stenosis, and other pathologies, and to assess the best treatment option s and available drugs. The spine is the second most commonly affected site with PD. About one-third of patients with spinal involvement exhibit sympto ms of clinical stenosis. In only 12-24% of patients with PD of the spine is back pain attributed solely to PD, while in the majority of patients back pain is either arthritic in nature or a combination of a pagetic process an d coexisting arthritis. Neural element dysfunction may be attributed to com pressive myelopathy by pagetic bone overgrowth, pagetic intraspinal soft ti ssue overgrowth, ossification of epidural fat, platybasia, spontaneous blee ding, sarcomatous degeneration and vertebral fracture or subluxation. Neura l dysfunction can also result from spinal ischemia, when blood is diverted by the so-called "arterial steal syndrome". Because the effectiveness of ph armacologic treatment for pagetic spinal stenosis has been clearly demonstr ated, surgical decompression should only be instituted after failure of ant ipagetic medical treatment. Surgery is indicated as a primary treatment whe n neural compression is secondary to pathologic fractures, dislocations, sp ontaneous epidural hematoma, syringomyelia, platybasia, or sarcomatous tran sformation. Since, in the majority of cases with pagetic spinal involvement , there are also coexisting osteoarthritic changes, antipagetic medical tre atment alone may be disappointing. Therefore, one must be careful before at tributing low back pain to PD alone. Five classes of drugs are available fo r the treatment of PD: bisphosphonates, calcitonins, mithramycin (plicamyci n), gallium nitrate, and ipriflavone. Bisphosphonates are the most popular, and several forms have been investigated, but only the following forms hav e been approved for clinical use: disodium etidronate, clodronate, aledrona te, risedronate, neridronate, pamidronate, tiludronate, ibadronate, aminohy droxylbutylidene bisphosphonate, olpadronate, and zoledronate. Several of t hese forms are still under investigation.