Over the past decade, many medical lower limb exoskeletons have been developed and exploited. The advantage of such a systems is to ensure the mobility of paraplegic patients, as well as their physical rehabilitation. However, existing solutions have not been widely available among the disabled population, particularly adolescents, due to the limitations of their conception caused by the rapid physical growth and morphological variation of this population.In this paper, a new scalable structure of the exoskeleton is proposed as a feasible solution to the problem of morphological changes. As this is the first time the generic term "scalability" has been used, its requirements and design methods, including the morphological changes and alignment, are presented in detail to better meet the growing needs for such a promising device. The evaluation of the proposed scalable structure shows a promising utility that is illustrated by several experimental scenarios: the load capacity of the structure, the efficiency of the fixation mechanisms, the validation of the hip alignment mechanism and finally the validation of the evolutionary structure.