Figure 2
From: Prevalence of radiographic findings of femoroacetabular impingement in the Japanese population
Influence of acetabular retroversion on the development of arthritis in non-dysplastic hips. After a follow-up period of up to 180 months, the Kaplan-Meier estimate showed that patients with non-dysplastic hips and the crossover sign (COS) had an inferior prognosis (P = 0.027, log-rank test).