Bone Abstracts

Introduction: Osteogenesis imperfecta is a rare constitutional bone disease. The bone matrix is poor because of the often mutation on the gene coding for collagen I, leading to many fractures. Classification Sillence completed by Glorieux, describes the clinical variability. The management should be done case by case.

Study objective: Evaluate the clinical profile, biological and radiological of 5 newly diagnosed cases.

Material and methods: Descriptive study, conducted in 2015 at the Rheumatology department in collaboration with the orthopedics and pediatric trauma. Inclusion criteria were patients responding to the diagnosis of osteogenesis imperfecta classification. All have benefited from a clinical evaluation of biological explorations, especially calcium phosphate, standard radiological assessments and BMD dual energy X-ray (Hologic). Treatment with pamidronate was considered in all cases, in association with orthopedic and rehabilitative care according indication.

Results: We identified five cases. It was three boys and two girls. The average age was 6.2 years. According to the classification of Silence and Glorious, three cases were authenticated osteogenesis imperfecta type III; iterative fractures, short stature, skeletal deformities with kyphoscoliosis, premature loss of walking confining patients in wheelchairs, dentinogenesis imperfecta, blue sclera and laxity ligament. Form IV was found in two cases; presence of hypertrophic callus, ossification of the interosseous membrane of the forearm and shortening of the humerus and femur. Paternal history of the disease was found in two patients. Fractures were multiple, predominant in the lower limbs, at the humerus and thorax in one case respectively. The radiological assessment confirmed the fracture lines to members, and spine in two cases. Bone densitometry found severe osteoporosis in all patients, at the three sites. Laboratory tests were normal. Four patients have benefited surgical treatment, using telescopic nails, combined with rehabilitative care. Pamidronate was considered in all patients according to the pediatric protocol.

Discussion and conclusion: Osteogenesis imperfecta is a rare disease, heterogeneous in its presentation. Genes other than type I collagen could be transferred, responsible for a recessive transmission and serious presentation in childhood. A new classification of the disease results in 12 types. Type I is the most benign form, and most common in rheumatology. The management is always multidisciplinary. It is guided by the same considerations as those of other bone fragility; in particular, the compensation of a calcium and vitamin D deficiency. Bisphosphonates remain effective.