Aims: Imaging assessment for the clinical management of femoroacetabular impingement (FAI) syndrome is controversial because of a paucity of evidence-based guidance and notable variability among practitioners. Hence, expert consensus is needed, because standardised imaging assessment is critical for clinical practice and research. We aimed to establish expert-based statements on FAI imaging by using the formal methods of consensus-building. This is the second part of a three-part consensus series, and focuses on 'General issues' and 'Parameters and reporting'.
Methods:The Delphi method was used to formally derive consensus among 30 panel members from 13 countries. Forty-four questions were agreed upon, and relevant seminal literature was circulated and classified in major topics ('General issues', 'Parameters and reporting', 'Radiographic assessment', 'Magnetic resonance imaging (MRI)' and 'Ultrasound') to produce answering statements. The level of evidence was noted for all statements, and panel members were asked to score their level of agreement (0-10). Either 'group consensus', 'group agreement', or 'no agreement' was achieved.Results: Forty-seven statements were generated and group consensus was reached for 45. Twenty-five statements pertaining to 'General issues' (nine addressing diagnosis, differential diagnosis and postoperative imaging) and 'Parameters and reporting' ( 16addressing femoral/acetabular parameters) were produced.
Conclusions:The first international Delphi-based consensus on FAI imaging was developed. The available evidence was reviewed critically, recommended criteria for diagnostic imaging highlighted, and the roles of different imaging parameters assessed.The resulting statements can serve as a tool for practitioners working with hip-related pain to reduce clinical variability and guide further research for FAI management.
Key points Radiographic evaluation (anteroposterior radiograph of the pelvis and a lateral view of the hip, preferably a Dunn 45° view) with a reproducible methodology is the cornerstone of hip-imaging assessment and minimum imaging study that should be performed when assessing adult patients for FAI. In selected cases, cross-sectional imaging is warranted because MRI with a dedicated protocol is the 'gold standard' imaging modality for the comprehensive evaluation, differential diagnoses assessment, and surgical planning of FAI. For acetabular morphology, coverage (centre-edge angle of Wiberg and acetabular index) and version (crossover, posterior wall, and ischial spine signs) should be assessed routinely. On the femoral side, the morphology of the head-neck junction (alpha angle and offset), neck morphology (neck-shaft angle) and torsion (antetorsion angle) should be assessed routinely.
ClinicalRelevance Imaging assessment for FAI is unstandardised because of a paucity of evidencebased guidance and lack of consensus among experts on which imaging modalities, diagnostic criteria, and parameters should be used/assessed routinely. This Delphibased consensus, aims t...
