Background: Several anatomical studies regarding the value of hip rotation center (HRC) and femoral offset (FO) have been performed in Western populations. However, there are a few data on hip morphological values in the Chinese population based on CT scans. This study measured the values of the hip and pelvis, especially HRC and FO, in a Chinese population and compared them with the published values obtained from Western populations.
Patients and methods: One hundred patients (50 females and 50 males) were included in the present study, and 3D-CT reconstructions of the hip and pelvis were generated. The mean age was 51.4 ± 8.9 years and mean body mass index (BMI) was 23.5 ± 2.6 kg/m2. All the morphologic measurements were compared between genders and sides, and the relationships between different parameters were analyzed.
Results: The mean FO values were 38.4 ± 4.7 mm and 35.6 ± 4.4 mm for the males and females, respectively. A significant negative correlation was noted between FO and neck shaft angle (NSA) in both genders (r = - 0.262, P = 0.009 for the males, r = - 0.350, P ≤ 0.001 for the females). A significant positive correlation was found between horizontal distance (HD) and diameter of the femoral head (DFH) in both genders (r = 0.734, P ≤ 0.001 for the males, r = 0.658, P ≤ 0.001 for the females). A significant positive correlation was noted between HD and pelvic width (PW) in males (r = 0.455, P ≤ 0.001). A significant positive correlation was also noted between HD and pelvic height (PH) in males (r = 0.318, P ≤ 0.001). A significant positive correlation was observed between FO and pelvic cavity height (PCH) in males (r = 0.411, P ≤ 0.001), and a significant positive correlation was observed between VD and PCH in females (r = 0.497, P ≤ 0.001). The tip of the greater trochanter was, on average, 7.0 mm higher than the femoral head center. Relationships between DFH and pelvic morphometric parameters were also observed.
Conclusion: The present morphological data and the relationships between them can be applied to design better ethnic-specific THA prostheses and preoperative plans.
Keywords: Anatomy; Image reconstruction; Pelvis; Total hip arthroplasty.