Introduction: The definition of pelvic obliquity angle (PO) still unclear in the normal population. Several factors might cause the obliquity i.e. hip osteoarthritis, developmental dysplasia of hip, trauma, scoliosis and spine related factors. Perhaps, pelvic obliquity is expressed as a deviation of neutral alignment in the normal population. We developed present study to evaluate the distribution of pelvic obliquity angle in normal population.
Method: present study retrospectively enrolled on 134 cases (70 female and 64 male) without any problem of spine, pelvic and lower extremity abnormality who referred to our institution from January 2017 to January 2018 for non-orthopedic problems. We retrospectively reviewed radiographs from institutional PACS and measured pelvic obliquity angle using mediCAD Classic software (version 3.50.0.1, Hectec, Landstuhl, Germany). Finally, all data were analyzed with SPSS software (version 24.0, USA).
Result: present study show that all data has significant relationship in one sample T test. All PO angles were normally distributed in kurtosis and skewness test. The patients were aged with a mean of 39.6 ±16.8 in current study. The mean of PO angle was 2.18 ±1.6 in all patients and 0.13 standard error of mean. There was no significant differences between male and female genders (2.07 ±1.6 vs 2.27±1.6, P=0.47). This study reveal that age and PO angle had not any correlation (P=0.165).
Conclusion: despite this fact, there was an attitude that PO angle normally is in neutral alignment, our result uncover that the normal range of PO angle was not neutral and ranged from 0.58 to 4.4 degrees with one standard deviation from mean in the normal population.