Registration-based patient-specific musculoskeletal modeling using high fidelity cadaveric template model

Abstract

We propose a method to construct patient-specific musculoskeletal model using a template obtained from a high fidelity cadaver images. Musculoskeletal simulation has been traditionally performed using a string-type muscle model that represent the line-of-forces of a muscle with strings, while recent studies found that a more detailed model that represents muscle’s 3D shape and internal fiber arrangement would provide better simulation accuracy when sufficient computational resources are available. Thus, we aim at reconstructing patient-specific muscle fiber arrangement from clinically available modalities such as CT or (non-diffusion) MRI. Our approach follows a conventional biomedical modeling approach which first constructs a highly accurate generic template model which is then registered using the patient-specific measurement. Our template is created from a high-resolution cryosectioned volume and newly proposed registration method aligns the surface of bones and muscles as well as the local orientation inside the muscle (i.e., muscle fiber direction). The evaluation was performed using cryosectioned volumes of two cadavers, one of which accompanies images obtained from clinical CT and MRI. Quantitative evaluation demonstrated that the mean fiber distance error between the one estimated from CT and the ground truth was 4.16, 3.76, and 2.45 mm for the gluteus maximus, medius, and minimus muscles, respectively. The qualitative visual assessment on 20 clinical CT images suggested plausible fiber arrangements that would be able to be translated to biomechanical simulation.