Abstract: BACKGROUND: The complexity of hip joint anatomy makes it difficult to quantitatively assess by parameter indexes, and real-image rendering technology is important for the accurate display of hip joint microstructure and detection of diseases.
OBJECTIVE: To evaluate the anatomical and morphological parameters of the hip joint through three-dimensional digital measurement by CT multi-planar reconstruction and cinematic rendering, compare the differences and analyze the correlation, so as to provide a precise anatomical parameter basis for the diagnosis and evaluation of hip-related diseases and hip arthroplasty.
METHODS: Spiral CT images of the hip joints of 156 subjects (312 sides) aged 18 years or older without hip trauma or disease were collected and divided into six groups, each 10 years old. The CT images were processed with cinematic rendering and multi-planar reconstruction. Sharp angle, femoral head distance, acetabular coverage, acetabular depth, Cape verde, femoral offset, center edge angle, acetabular anterior section angle, posterior acetabular section angle, and acetabular anteversion were measured bilaterally. SPSS statistical software was used to compare the differences in anatomical parameters of bilateral hip joints in different age groups, and to analyze the correlation between different anatomical indexes and clinical baseline data. 
RESULTS AND CONCLUSION: (1) Comparison of the anatomical parameters of the hip joint by left and right sides exhibited that the difference between Cape verde and femoral offset was statistically significant (P < 0.05). (2) Compared by gender, the sharp angle, femoral offset, femoral head distance and anterior acetabular tilt were greater in women than in men (P < 0.05). (3) Compared by different age groups, the values of the young group in the indexes of acetabular depth, acetabular coverage, acetabular anterior section angle, posterior acetabular section angle, anterior acetabular tilt, and center edge angle were smaller than those of the old group (P < 0.05). (4) When acetabular coverage-traditional method was compared with acetabular coverage-innovative method and acetabular depth-coronal with acetabular depth-axial position, the differences were not statistically significant, but there was a significant correlation (r=0.76, 0.95, P < 0.01). Sharp angle was negatively correlated with body mass index, acetabular coverage, acetabular depth, center edge angle, acetabular anterior section angle, and posterior acetabular section angle (P < 0.05), and acetabular coverage, acetabular depth, center edge angle, acetabular anterior section angle, and posterior acetabular section angle were positively correlated with each other (P < 0.01). (5) It is indicated that cinematic rendering and multi-planar reconstruction technology facilitates accurate measurement and assessment of hip joint anatomical parameter indexes, and there are obvious differences in parameter indexes between different genders and age groups, with certain characteristic trends, and there are significant correlations between different anatomical parameter indexes.

Key words: cinematic rendering, hip joint, clinically applied anatomy, three-dimensional digital measurements, correlation