SPINAL OSTEOBLASTOMA - RELATIONSHIP BETWEEN PARAVERTEBRAL MUSCLE ABNORMALITIES AND SCOLIOSIS

Objective. To illustrate the variety of paravertebral muscle abnormali ties as seen on computed tomography (CT) or magnetic resonance imaging (MRT) in association with spinal osteoblastomas and correlate the fin dings with the presence of scoliosis. Design. In a retrospective study the clinical notes, plain radiographic, CT and/or MRI features were r eviewed for the presence of scoliosis and paravertebral muscle abnorma lity (either inflammation or atrophy). Patients. Twelve patients (7 ma le, 5 female) with a clean age of 17 years were studied. Three lesions occurred in the cervical spine, five in the thoracic spine and four i n the lumbar spine. Results and conclusions. Nine patients had scolios is. All patients with scoliosis (n=8) had an associated abnormality of the paravertebral muscles (usually atrophy with fatty replace ment). One patient with a lumbar lesion and no scoliosis had normal paraverte bral muscles. One patient with a cervical lesion had thoracic scoliosi s but no muscle abnormality in the cervical region, while two patients with cervical lesions and no scoliosis showed muscle abnormalities. T he results support the clinical hypothesis that scoliosis in patients with spinal osteoblastoma is due to paravertebral muscle spasm, althou gh this would not appear to be the case for cervical lesions.