Surgical Hip Dislocation for Treatment of Femoroacetabular Impingement Which are the Red Lights for Poor Results

Abstract

Background: Femoroacetabular impingement is a common source of hip pain and dysfunction, especially in young and active patients. It is considered to be the main cause of early hip osteoarthritis. We set the purpose to identify poor prognosis factors in the surgical treatment of femoroacetabular impingement. Methods: We realized a prospective observational study in a case series of 50 hips in 44 patients with femoroacetabular impingement operated with surgical hip dislocation between 2001 and 2006. Clinical, radiologic, surgical and functional factors of whole patients were assessed. Clinical outcomes were determined with a subjective scale. Also, functional assessment was performed with a modified Harris Hip Score (HHS). Both evaluations were applied at 6, 9, and 12 months, and so every year once. Finally, the statistical analysis was done with SPSS 15.0 software. Results: With an average of 6.2 post-operative years (5-10.1) of follow-up, 35 patients (70%) were “asymptomatic” (HHS=100), 11 patients (22%) “better” (HHS=94.09), and 4 patients (8%) “the same or worse” (HHS=68.25). 40% of patients older than 45 years old were “asymptomatic”, versus 77% younger than 45 years old (p=0.03). 37% of patients with mixed femoroacetabular impingement were “asymptomatic”, 87% of patients with cam-type and 82% with picer-type (p=0.003). The factors related to a poor prognosis were as follows: age >45 and mixed-type impingement; and other factors such as radiological osteoarthritis, labral injury and prolonged symptomatology were also associated to poor prognosis results in our study, without being statistically significant. Conclusion: Age > 45 years old and mixed type of impingement are significant statistic factors related to a poor prognosis in patients treated with surgical hip dislocation. This data are useful to predict the treatment outcome for each patient.