Application of the relationship between three-dimensional coverage and two-dimensional coverage of the acetabulum cup in total hip arthroplasty
10.3760/cma.j.cn121113-20240622-00359
- VernacularTitle:全髋关节置换术中臼杯三维覆盖率与二维覆盖率关系的应用研究
- Author:
Jinzi WANG
1
;
Wenju CHANG
1
;
Pei ZHANG
1
;
Zuqing CHEN
1
;
Yong ZHANG
1
;
Hai DING
1
Author Information
1. 蚌埠医科大学第一附属医院骨科，组织移植安徽省重点实验室，蚌埠 233000
- Publication Type:Journal Article
- Keywords:
Arthroplasty, replacement, hip;
Printing, three-dimensional;
Acetabulum;
Prosthesis implantation;
Coverage rate;
Abduction angle;
Anteversion angle
- From:
Chinese Journal of Orthopaedics
2024;44(24):1602-1610
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the correlation between three-dimensional (3D) true acetabular cup coverage and two-dimensional (2D) X-ray acetabular cup coverage in total hip arthroplasty (THA) and identify effective parameters for evaluating acetabular cup coverage.Methods:Sixteen pelvic models were 3D-printed from CT reconstruction data of healthy adult pelvises. Postoperative acetabular models were prepared using standard THA procedures. The postoperative models were centered on the acetabulum and positioned under a C-arm fluoroscope. Fluoroscopy was conducted by rotating the C-arm at different angles (15°, 30°, and 45°) to obtain anteroposterior (AP) and iliac oblique X-ray images of the hip joint. The 2D acetabular coverage at different fluoroscopic angles (AP, 15° iliac oblique, 30° iliac oblique, and 45° iliac oblique) was recorded and compared with the 3D acetabular coverage measured from the pelvic models. Two independent observers assessed related parameters (coverage, abduction angle, anteversion angle) from the 2D X-ray images, and inter-observer reliability was statistically analyzed. Differences between 2D and 3D acetabular coverage were compared, and multiple linear regression analysis was used to assess correlations between acetabular anteversion angle, abduction angle, and both 2D and 3D acetabular coverage.Results:The acetabular coverage for the 2D X-ray groups (AP, 15° iliac oblique, 30° iliac oblique, and 45° iliac oblique) was 87.37%±2.59%, 87.01%±2.53%, 85.39%±2.57%, and 83.20%±2.51%, respectively, with statistically significant differences ( F=6.700, P=0.001). The 45° iliac oblique group had significantly lower coverage than both the 30° iliac oblique group and the AP group, while the 30° iliac oblique group showed significantly lower coverage than the 15° iliac oblique group (all differences, P<0.05). The mean abduction and anteversion angles were 45.33°±2.22° and 14.61°±2.53°, respectively. The 3D acetabular coverage was 85.66%±2.51%. The 45° iliac oblique group had significantly lower coverage than the 3D coverage group ( P<0.05), whereas no significant difference was observed between the AP group and the 3D coverage group ( t=1.893, P=0.062). Multiple linear regression analysis revealed significant negative correlations between the acetabular abduction angle, anteversion angle, and both 2D and 3D acetabular coverage, with the following regression equations: 2D coverage=124.627-0.700× (abduction angle) -0.379× (anteversion angle) ( R2=0.814, P=0.001); 3D coverage=120.291-0.603× (abduction angle) -0.499× (anteversion angle) ( R2=0.917, P<0.001). Conclusion:Acetabular cup coverage rates vary with different X-ray projection angles, with the anteroposterior X-ray view potentially overestimating coverage. Changes in the abduction angle appear to significantly impact the differences between 2D and 3D coverage, thereby increasing errors in assessing true acetabular cup coverage. These discrepancies between 2D and 3D coverage should be carefully considered when evaluating minimal acetabular cup coverage.
