Femoroacetabular impingement-related deformities correlate with advanced osteoarthritis in asymptomatic caucasians over 60: A CT-based cross-sectional study.

Objective: Osteoarthritis (OA) is a common finding in the elderly population. Femoroacetabular Impingement (FAI)-related deformities can cause OA. Their prevalence and clinical relevance in the asymptomatic elderly population are unclear. This study aims to determine the prevalence of cam and pincer deformities in asymptomatic, non-orthopedic Caucasian patients over 60 years in computed tomography (CT) and correlate the presence of those deformities with radiological signs of OA. Design: CTs of oncological patients over 60 years without any previous history of hip pathology or pain, containing a complete scan of both hips, were included. All hips were analysed for signs of OA according to the Kellgren-Lawrence (KL) classification. The acetabular anteversion, acetabular sector angles (ASA), and alpha angles were measured in clockwise positions of the hip. All angles were modeled conditionally on KL, sex, age, and obesity using random-effects median regression. Results: One hundred ninety-five non-orthopedic patients (130 male, 65 female; mean age 70.4 years; 290 hips) were included. Signs of severe OA (KL 3/4) were found in 19.2 %. Patients over 80 years had significantly higher alpha angles at 9-11 o'clock, higher ASA at 9-12 o'clock, and a higher acetabular anteversion at the level of the acetabular roof. Individuals with advanced OA showed higher alpha angles, higher ASA, and a lower acetabular anteversion than those without/with moderate OA. Conclusions: This study provides an estimate of the distribution of FAI-related deformities within a population of individuals over 60 years with asymptomatic hips. The prevalence of these deformities is correlated with advanced OA.