Femoral torsion evaluation by computed tomography in a young Brazilian population with hip pain and femoroacetabular impingement.

INTRODUCTION: The aim of the study was to evaluate femoral torsion (FT) by computed tomography (CT) in young patients with hip pain and femoroacetabular impingement (FAI) in a Brazilian population. After the diagnosis of impingement, the complete analysis from the hip biomechanics and morphology has become essential. METHODS: Forty-one patients from 18 to 45 years presenting hip pain without arthrosis (Tönnis<2) were evaluated by CT scan from February 2017 to February 2018. All patients presented hip pain for at least 3 months and FAI. They have followed the same radiographic protocol and modified Harris Hip Score (mHHS) evaluation. Statistical analyses by software R version 3.4.4. with significance p < 0,05. RESULTS: After exclusion criterias, twenty-six patients (9 bilateral) were included, mostly man (73%). The average age was 35 years for both genders. BMI was 19 kg/m2 for women and 24 kg/m2 for men and the mean modified Harris Hip Score was 67 points. We have found femoral torsion changes in 11 hips with pain (31%) and high variability (60%). The mean FT was 14,5°, ranging from 0 to 39°. Patients with hip pain, CAM impingement and altered FT had no correlation when compared to controls (without pain) (p = 0.234), neither Mixed impingement (p = 0.314). Patients with Pincer impingement and painful hips had higher FT (16,63°) than controls (11,77°) (p = 0.045). Conclusion: The presence of torsional alterations in almost 1/3 of the patients with FAI and the high variability reveal the importance of measuring FT at this disease.