This chapter describes some of the aforementioned challenges. The management of paediatric spinal deformity can vary greatly in its complexity and in the resources required. In the case of Early-Onset Scoliosis (EOS) in particular, it is not infrequent that these challenges are far greater than in those of a patient representative of an average case of adolescent idiopathic scoliosis; managing a young child with a severe and complex deformity, with the frequent addition of significant comorbidities and that will probably require various surgical interventions starting at an early age can quite significantly stress the health system. The true prevalence of EOS is difficult to determine, mainly because it encompasses a variety of inhomogeneous diagnoses. EOS presents multiple additional challenges to the treatment of the spinal deformity itself. Growth-friendly instrumentation may be considered conceptually as a temporising procedure that should ultimately be replaced with a definitive instrumentation and fusion.