The dynamic measurement of acetabulum abduction angle under non-physiological state and its clinical significance

LI Ying; GENG Zuojun; ZHAO Xiujuan

doi:10.3969/j.issn.1002-7386.2016.13.008

Abstract：Objective To detect acetabulum abduction angle of pelvis at different sloping degrees through multi -slice spiral CT ( MSCT ) three-dimensional reconstruction pelvis , and to explore the reasonable placing angle during total hip arthroplasty ( THA) under non-physiological state .Methods One hundred patients ( 50 males and 50 females ) including 200 acetabulums were scanned by MSCT to reconstruct pelvis into stereoscopic picture by means of valume rendering technique (VRT),then to make pelvis at different inclination (10°~90°) in simulated pathological conditions , to reconstruct coronal view image by multiplanar reconstruction ( MPR) so us to measure abduction angle of acetabulum in both sides .The statistical software was used to calculate mean value and standard deviation , to draw the related changing curve of abduction angle of acetabulum changing with pelvis sloping degree in non -pathological conditions in order to find out related regulation .Results The results by MSCT showed that acetabular abduction angles were as follows :when pelvis inclination was changed from 10° to 90°, abduction angle change showed a parabola curve , when pelvis inclination was 70°, the abduction angle was 48°,which suggested that not only the acetabular coverage to femoral head was the best , but also the articular stability was the best . Besides there was no significant difference in acetabulum abduction angle under the same condition between males and females ( P >0.05).Conclusion There is no significant difference in the acetabular abduction angle between males and females , which suggests that the influence of gender factors on acetabular abduction angle is not obvious .The acetabular abduction angle is changed with the changing of pelvic inclination , showing a parabola , thus, which can provide theoretical basis for selecting reasonable placing angle in THA .