Descriptive epidemiology of femoroacetabular impingement: a North American cohort of patients undergoing surgery

Background: Symptomatic femoroacetabular impingement (FAI) is associated with hip pain, functional limitations, and secondary osteoarthritis. There is limited information from large patient cohorts defining the specific population affected by FAI. Establishing a large cohort will facilitate the identification of "at-risk" patients and will provide a population for ongoing clinical research initiatives. The authors have therefore established a multicenter, prospective, longitudinal cohort of patients undergoing surgery for symptomatic FAI.

Purpose: To report the clinical epidemiology, disease characteristics, and contemporary surgical treatment trends in North America for patients with symptomatic FAI.

Study design: Cross-sectional study; Level of evidence, 3.

Methods: Upon approval of the institutional review boards at 8 institutions, 12 surgeons enrolled consecutive patients undergoing surgical intervention for symptomatic FAI. Patient demographics, physical examination data, radiographic data, diagnoses, operative data, and standardized patient-reported outcome measures were collected. The first 1130 cases are summarized in this study.

Results: A total of 1076 consecutive patients (1130 hips) were enrolled; 55% (n = 622) were female, and 45% (n = 508) were male, with an average age of 28.4 years and average body mass index (BMI) of 25.1. Demographics revealed that 88% of patients who were predominantly treated for FAI were white, 19% reported a family history of hip surgery, 47.6% of hips had a diagnosis of cam FAI, 44.5% had combined cam/pincer FAI, and 7.9% had pincer FAI. Preoperative clinical scores (pain, function, activity level, and overall health) indicated a major dysfunction related to the hip. Surgical interventions were arthroscopic surgery (50.4%), surgical dislocation (34.4%), reverse periacetabular osteotomy (9.4%), limited open osteochondroplasty with arthroscopic surgery (5.8%), and limited open by itself (1.5%). More than 90% of the hips were noted to have labral and articular cartilage abnormalities at surgery; femoral head-neck osteochondroplasty was performed in 91.6% of the surgical procedures, acetabular rim osteoplasty in 36.7%, labral repair in 47.8%, labral debridement in 16.3%, and acetabular chondroplasty in 40.1%.

Conclusion: This multicenter, prospective, longitudinal cohort is one of the largest FAI cohorts to date. In this cohort, FAI occurred predominantly in young, white patients with a normal BMI, and there were more female than male patients. The disease pattern of cam FAI was most common. Contemporary treatment was predominantly arthroscopic followed by surgical hip dislocation.