Backgrounds: Osteogenesis imperfecta (OI) is an inherited bone disease caused by qualitative or quantitative defects in type I collagen, and is characterized by bone fragility and ligamentous laxity. Spine disorder is an important symptom in children with OI, and respiratory difficulties secondary to spinal disorder were identified as a main cause of death in these patients. Reduced fracture rates and prevention of long-bone deformities have been reported in children with OI who are given bisphosphonates (BPs). However, It is still unknown whether BP therapy prevents the occurrence and progression of scoliosis in children with OI.
Objectives: To clarify the prevalence of scoliosis and determine risk factors for scoliosis development in children with OI who underwent treatment with intravenous pamidronate (PAM).
Methods: Children with OI who had no scoliosis at the first PAM administration and who underwent PAM therapy alone were retrospectively reviewed. Using dual-energy x-ray absorptiometry, we measured the L1L4 scoliotic angle (Cobb angle) and assessed coronal vertebral deformity over time. We examined the relationship between scoliosis and type of OI (Sillence classification: types I, III, and IV), z-scores of BMD in L2L4 of the lumbar spine, patients age at first PAM administration, frequency of PAM administration, physical mobility, and the presence or absence of corrective osteotomy in the lower extremities.
Results: We found the prevalence of scoliosis to be 19% in 37 children with OI who underwent PAM therapy for a mean of 9.8 times, and the incidence of scoliosis were lower than has been reported in previous studies (39100%) of patients who were not treated with BP. Sillence types III and IV and the presence of coronal vertebral deformity were significant risk factors for the development of scoliosis (P=0.03). Starting BP therapy in early childhood prevented the occurrence and progression of scoliosis in children with types III and IV OI (P=0.03).
Conclusions: This study suggest that BP decreases the incidence of vertebral deformity associated with bone fragility and subsequently decreases the incidence of occurrence and progression of scoliosis in children with OI, in particular those with type III or IV.
Disclosure: The authors declared no competing interests.
27 - 30 Jun 2015