Imaging Methodology for Hip Preservation: Techniques, Parameters, and Thresholds.

The concept of hip impingement and hip-preserving surgery has been appreciated in more detail since 2001 when a new surgical approach was reported and a hypothesis linking femoroacetabular impingement (FAI) with osteoarthritis was presented. Paralleling the introduction of hip arthroscopy, these events led to an increasing interest in the hip, and the number of publications has risen rapidly over the past 15 years, despite limited evidence levels and inconsistent methodology. Accordingly, etiology, diagnosis, prognosis, and the effects of treatment for FAI are still elusive due to a number of uncertainties and a lack of clear diagnostic criteria. Future research must focus on developing high-quality scientific studies, so thorough and reproducible methodology is needed. This review provides researchers, radiologists, and clinicians with a comprehensive approach to hip imaging with a focus on strategies to help guide the clinical diagnosis. Using evidence from current literature and knowledge from experienced clinicians, some of the imaging methodology challenges are deciphered.