Surgical hip dislocation in symptomatic cam femoroacetabular impingement: what matters in early good results?

Femoroacetabular impingement (FAI) that constitutes a repetitive impact of the proximal femur against the acetabular rim is a well known observation in young adults with persisting groin pain and limited range of hip motion [1]. Depending on the underlying mechanism, FAI is further classified as cam-, pincer- or mixed-type. In cam-FAI, the impingement results from an insufficient femoral head-neck offset that may cause cartilage and labrum damage especially during hip flexion. In pincer-FAI, the impingement arises from focal or general acetabular over-coverage probably provoking continuous frontal contact between femoral neck and acetabular labrum during hip flexion. In mixed-FAI, a combination of both mechanisms revealing a damage pattern with combined cam and pincer pathology may be observed.FAI by itself is not a disease per definition and a variety of factors such as biological tissue integrity remain important. However, emerging evidence has been anticipated that the repetitive abnormal abutment between proximal femur and acetabular rim may eventually lead to early osteoarthritis (OA) of the hip joint [1-3]. In order to possibly stop or delay the onset of the same as well as for managing symptoms, surgical treatment may become necessary [4].The safe surgical hip dislocation for correction of the morphological abnormality represents a well established technique that proved a low rate of complication and allows for examination and treatment of the entire joint during surgery [2,5-8]. However, recently only a small number of reports in the English literature can be referred that depict the clinical outcome of this approach in various types of FAI [2,5,9-12] and treatment of various grades of FAI is still a point for discussion - in research meetings as well as in daily clinical practice.Therefore, our aim in this study was to evaluate the clinical outcome of patients who had undergone surgical hip dislocation and debridement due to symptomatic cam-FAI within a fol