The clinical study protocol design is limited to patients at the highest risk of progressing to needing multi-level fusion surgery. There are no medical devices cleared by the FDA to treat late juvenile or early adolescent onset of idiopathic scoliosis. The HemiBridge System is the first mechanical compression device FDA approved for pediatric investigational use. The proposed study is the first use in humans of the HemiBridge System. The clinical trials will enable the study sponsor to gather prospective information to continuously improve the product, its indications, the next study phase clinical protocol design and recommended surgical technique.