Essilfie AA, Bloom DA, Zusmanovich M, et al. - The present study was performed to ascertain the modified Harris Hip Score (mHHS) and Non-Arthritic Hip Score (NAHS) at 2-year follow up in patients who had undergone staged bilateral hip arthroscopy versus age-, gender-, and body mass index–matched patients who underwent unilateral hip arthroscopy. Between January 2007 and December 2017, researchers distinguished individuals who had undergone staged bilateral primary hip arthroscopy for the indication of femoroacetabular impingement (FAI) with a minimum 2-year follow-up. The control group comprised patients who had undergone a unilateral hip arthroscopy for FAI. They examined the mHHS and the NAHS. They matched 42 patients (84 hips) in the bilateral group with 84 patients (84 hips) in the unilateral group. Compared with baseline, at 2 years of follow up, bilateral hip arthroscopy for the indication of FAI has improved mHHS and NAHS. No difference was found in 2-year mHHS and NAHS in patients who had undergone bilateral hip arthroscopy and unilateral hip arthroscopy. In comparison with those who had undergone the second surgery within 17 months of the index procedure, patients in the bilateral hip arthroscopy group that had the contralateral surgery longer than 17 months from index procedure had lower 2 year follow up mHHS and NAHS scores.