EP4.15 Subject-Specific Hip Capsule Geometry Modeling Using Elastic Mesh Wrapping

Abstract The hip capsule is a critical stabilizing structure of the joint. Despite the importance of accurate geometric representation for reliable computational analyses, its complex anatomy is frequently oversimplified or omitted in biomechanical models. This study aimed to develop a computationally efficient, subject-specific framework for reconstructing hip capsule geometry. A structurally informed volumetric mesh-wrapping algorithm was used to generate capsule geometries. Capsule geometries were generated for twelve cadaveric hips from six donors across seven joint configurations and validated against high-resolution 3D surface scans. To further illustrate functional interpretability, a geometry-based deformation measure was evaluated to illustrate the local deformation patterns in each ligament. Geometric validation demonstrated close agreement, with a pooled mean surface deviation of 2.13 ± 0.54 mm across ligament regions and joint positions. Although error distributions were region-dependent, they remained consistent across joint configurations, indicating positional robustness. The predicted deformation patterns exhibited trends consistent with established capsular biomechanics. The proposed framework enables automated generation of anatomically consistent hip capsule geometries with minimal manual intervention, providing a computationally efficient basis for large-scale biomechanical simulations.