Methods: Soft tissue pathology will be examined in a prospective cohort study on 100 patients with hip dysplasia prior to and one year after surgery. Pathology will be examined using ultrasonography and the Clinical Entities Approach that focus on pathology of the iliopsoas, adductors, rectus abdominis, gluteus medius and hamstrings. Furthermore, hip muscle strength is tested with a dynamometer, hip related health is measured with the Copenhagen Hip and Groin Outcome Score (HAGOS) and physical activity is measured with triaxial accelerometers during a period of 7 days.