Radiographic Prevalence of Femoroacetabular Impingement in a Young Population with Hip Complaints is High

Background: Femoroacetabular impingement (FAI) is reportedly a prearthritic condition in young adults that can progress to osteoarthritis. However, the prevalence of FAI is unknown in the young, active population presenting with hip complaints.

Questions/purposes: We sought to determine (1) the prevalence of radiographic findings of FAI in a young, active patient population with complaints localized to the region of the hip presenting to primary care and orthopaedic clinics; (2) the percentage of films with FAI with an official reading suggesting the diagnosis; and (3) whether the Tönnis grades of osteoarthritis corresponded to the findings of FAI.

Methods: We performed a database review of pelvic and hip radiographs obtained from 157 young (mean age 32 years; range, 18-50 years) patients presenting with hip-related complaints to primary care and orthopaedic clinics. Radiographs were analyzed for signs of FAI (herniation pits, pistol grip deformity, center-edge angle, alpha angle, and crossover sign) and Tönnis grade. Radiology reports were reviewed for a diagnosis of FAI.

Results: At least one finding of FAI was found in 135 of the 155 patients (87%). Four hundred thirteen of 487 radiographs (85%) had been read as normal and one read as showing FAI. Tönnis grades did not correlate with radiographic signs of FAI.

Conclusions: Radiographic evidence of FAI is common in active patients with hip complaints. Increased awareness of FAI in primary care, radiology, and orthopaedic clinics and additional research into the long-term effects of management are warranted.

Level Of Evidence: Level II, diagnostic study. See the Guidelines for Authors for a complete description of levels of evidence.