The purpose of this research is to evaluate the effectiveness of a fascia iliaca nerve block in reducing post-operative pain within the first 24 hours following hip arthroscopy. Additionally, the pharmacokinetics of the drug ropivacaine will be studied via laboratory analysis of blood samples. Ultimately, the objective of this research is to develop a standard of care or best practice for the management of post-operative pain following hip arthroscopy. This study will include the entire age range of patients who are seen for hip arthroscopy at Boston Children's Hospital, for which there is a 35 year age limit. Both sexes will be included in the study.