OSTEOID OSTEOMA IN LUMBAR SPINE EXCISIONAL BIOPSY UNILATERAL STABILISATION BONE GRAFTING DONE

Osteoid osteoma is a lesion of bony origin, first described by Jaffe in 1935. These lesions are most common in the spine (42), affect men more than women, and are most common the second decade. The lumbar spine is the most common location, the cervical next, and the thoracic last, and the lesion is almost invariably located in the posterior elements. Few osteoid osteomas of vertebral bodies have been reported. This lesion is not locally aggressive and is defined by a size of less than 2 cm larger lesions are classified as osteoblastomas. Pain is the primary complaint in 83 of patients, is worse at night with awakening in nearly 30, and is relieved by aspirin in 27. Because of the location in the posterior elements, radiculopathy occurs in 28 of patients. A painful scoliosis may result, with the lesion usually present at the apex of the curve in the concavity. Although various curve types may result, the usual structural features of vertebral rotation normally present in idiopathic scoliosis are absent. The resultant scoliosis is rigid and rapidly progressive. Diagnosis can be difficult because early radiographs may appear normal. Frequently, a sclerotic lesion of the pedicle is all that is apparent, and even this may be a subtle asymmetry. Later, the usual configuration of a central nidus with surrounding sclerosis may be found, but it is typical in appearance in only half of patients. Oblique radiographs can be helpful when the pedicle, facet, and pars interarticularis are studied. A radio isotopic bone scan is most helpful in accurate localization, and CT scanning often shows the nidus. Treatment should consist of surgical excision of the lesion if symptoms fail to improve, or the scoliosis is progressive. If the spine is considered unstable because of facet or pedicle removal, bone grafting a single-level fusion stabilization is done simultaneously. Complete excision should result in improvement in the angular degree of the scoliosis.