Percentage of patients 18 years of age and older who completed a baseline and, within the CY(calendar year) reporting period of Jan. 1, 20xx - Dec.31, 20xx, a follow-up patient-reported hip functional assessment (e.g. Harris Hip Score, HOOS, HOOS-PS, HOOS Jr, Oxford Hip, or equivalent CAT assessment if available) that showed a statistically significant improvement in comparison to initial assessment or who had already reported a score in which there is no room for statistical improvement. The use of Patient Reported Outcomes (PROs) in clinical research is well documented.