Persistent or recurrent symptoms after arthroscopic surgery for femoroacetabular impingement: A review of imaging findings.

Hip arthroscopy is one of the most rapidly growing and evolving orthopaedic subspecialties. With the recent dramatic increase in the volume of hip arthroscopy performed there has been an increase in the number of symptomatic patients following arthroscopy for femoroacetabular impingement. Imaging has a key role in determining the need for revision surgery and in preoperative planning. Although the revision rate for hip arthroscopy is 3-9%, little has been published about the imaging findings associated with unsatisfactory treatment outcomes. This review discusses the significance of pre-existing osteoarthritis and underlying hip dysplasia and describes the causes of persistent symptoms. Recent literature on extra articular impingement and causes of microinstability are presented. Post-operative appearances are described focussing on the clinically relevant imaging findings. The challenges of evaluating the labrum after repair and specific findings associated with anchor failure and iatrogenic chondrolabral injury are discussed. The purpose of this article is to review the causes of unsatisfactory treatment outcomes after hip arthroscopy, role of imaging and indications for revision arthroscopy.