https://doi.org/10.1177/1120700018771927 HIP International 1–9 © The Author(s) 2018 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/1120700018771927 journals.sagepub.com/home/hpi HIP HIP International Introduction The number of hip arthroscopies performed has increased dramatically during the last 20 years. According to the statis- tics of the American Board of Orthopaedic Surgery (ABOS), there was an 18-fold increase in the number of hip arthrosco- pies performed between 1999 and 2009. 1 Montgomery et al. 2 reported a 365% increase in the rate of hip arthroscopy in the United States from 2004 to 2009 in a study based on a national database of orthopedic insurance records. Hip arthroscopy has been reported to yield successful clinical outcomes in multiple case-series studies 3–11 and is a well-established tool in hip preservation surgery. The overall complication rate of this procedure was 4% (95% CI 2.9–5.2%) according to a meta-analysis of 6962 cases in 2013. 12 However, the post-operative clinical outcome is not always satisfactory and revision hip arthroscopy pro- cedure is necessary. 13 Philippon et al. 14 compared the clini- cal outcomes of primary versus revision hip arthroscopy patients and reported lower HOS-ADL, HOS-SPORTS, WOMAC, and SF-12 physical components scores (pre- operatively and post-operatively) in the revision group compared to patients that underwent primary surgery. However, both groups presented significant outcome score improvements compared to their pre-operative score val- ues. Most of the revision cohort patients presented with residual FAI lesions while all of them underwent lysis of adhesions at the time of revision procedure. A recent sys- tematic review showed that residual FAI lesions was the leading cause of revision hip arthroscopy with a mean interval between the primary and revision operation being Current concepts in revision hip arthroscopy Renato Locks, Ioanna Bolia, Hajime Utsunomiya, Karen Briggs and Marc J Philippon Abstract Hip arthroscopy is an evolving procedure and its indications have expanded. The number of patients undergoing this procedure has increased significantly as well as the number of surgeons being trained. This has resulted in a notable increase in post-operative complication rates creating the need to develop advanced hip arthroscopic techniques. Revision hip arthroscopy is often complex and many factors should be considered to achieve a satisfactory clinical outcome. Careful pre-operative planning and agreement of expectations between the physician and patient regarding the procedure are important. This review describes several advanced treatment options that are used mainly in revision or complex primary hip arthroscopy cases. Labral reconstruction or augmentation technique is used in cases of severely deficient acetabular labral tissue to restore the fluid seal mechanism. In cases of symptomatic (often post-operative) adhesion formation, a spacer between the labrum and the joint capsule is useful for pain relief and prevention of future adhesions. Large defects of the capsule due to previous unrepaired capsulotomy or any other cause can be addressed with the capsular reconstruction technique. Ligamentum teres reconstruction using an anterior tibialis allograft is indicated in patients with hip instability and persistent pain after previous debridement or with complete tears of this structure. The senior author’s treatment of choice in cases of previous over-resection of CAM impingement is the remplissage technique to restore the bony defect of the femoral head-neck junction and preserve the joint seal. Keywords Capsule, hip arthroscopy, labrum, ligamentum teres, techniques Date received: 27 February 2017; accepted: 31 December 2017. Steadman Philippon Research Institute, Vial, CO, USA Corresponding author: Marc J Philippon, Steadman Philippon Research Institute, 181 West Meadow Drive, Suite 400, Vial, CO 81657, USA. Email: drphilippon@sprivail.org 771927HPI 0 0 10.1177/1120700018771927HIP InternationalLocks et al. review-article 2018 Review Article