The classic Sillence classification of the four types of osteogenesis imperfecta (OI) has been extended by six additional forms in recent years. OI is a heterogeneous disease, which can exhibit a mild, moderate and severe clinical picture. The clinical variability is expressed by a different frequency of fracture incidences and bone deformity risks so that both factors lead to very different degrees of mobility and autonomy of patients. The treatment principles comprise long standing medication of bisphosphonates, rehabilitation measures and orthopedic treatment. The orthopedic treatment uses modern techniques of conservative and operative fracture management for fracture stabilization and modern telescopic rods for deformity correction. These combined treatment modalities have given an improved quality of life to OI patients of all severity grades.