The prevalence of femoroacetabular impingement as an aetiologic factor for end-stage degenerative osteoarthritis of the hip joint: analysis of 1,000 cases.

OBJECTIVE

The main purpose of the present study was to determine the prevalence of FAI among patients who underwent total hip arthroplasty (THA) with the diagnosis of end-stage osteoarthritis (OA) of the hip joint in a tertiary referral centre.

DESIGN

A retrospective search of the institutional archive database for patients who had undergone THA between the years 2005 and 2010 was conducted with the analysis of the recorded radiographic images. A total of 1,004 patients including 690 (68.7%) females and 314 (31.3%) males were identified. All radiographs were reviewed by 3 of the authors. Intra- and interobserver consistencies were calculated. The prevalence of femeroacetabular impingement (FAI) as a predisposing diagnosis resulting in end-stage degenerative joint disease treated with THA was determined.

RESULTS

The most common diagnosis was developmental dysplasia of the hip (DDH). The predisposing aetiologic factor leading to end-stage degenerative hip disease treated with THA was undetermined for 26 patients (2.6%). The number of patients who were diagnosed as cam-type FAI by all of the observers was 83, whereas it was 16 for pincer-type FAI. Interobserver agreement was very high in the evaluation of the stated ethiologies of hip osteoarthritis. The contingency coefficient for the diagnosis of FAI was 0.71 between observers.

CONCLUSIONS

Our study may be a reference for further investigations to develop a better understanding of the underlying pathological factors in patients undergoing THA due to end-stage OA of the hip joint.