Scoliosis and spine involvement in fibrous dysplasia of bone

Few studies focused on the prevalence of scoliosis and involvement of the spine in patients with fibrous dysplasia (FD) of bone. We examined for FD involvement of the spine and scoliosis in 56 patients affected by FD of bone. Fifty patients were part of a cohort reported in a multicentric study on FD promoted by European Pediatric Orthopedic Society (EPOS) in 1999, and six were new patients. There were 30 females and 26 males (mean age 12.5 years; range 1-42 years). Twenty-three had monostotic FD, 9 polyostotic FD, and 24 McCune-Albright Syndrome (MAS). Scoliosis was observed in 11 cases of polyostotic FD and MAS (33.3%). In seven of the patients with scoliosis (63.3%) spine was involved by FD lesional tissue. FD lesions involved the thoracic or lumbar spine in all patients but one, where cervical spine was also affected. A correlation between scoliosis and either spinal (p<0.01) or pelvic lesions (p<0.05) and pelvic obliquity (p<0.01) was observed. Three of the 11 patients showed familiarity for scoliosis but in 2 of them spine was involved by FD. Scoliosis and spine involvement were never detected in monostotic FD. This study indicates that in FD patients with polyostotic disease (1) the prevalences of FD involvement of the spine and scoliosis are high enough to include spine in the clinico-radiographic survey of these patients, and (2) the involvement of the spine and pelvis by FD lesions and pelvic obliquity are important determinants in the occurrence of scoliosis.