(BIO17) 3D biomechanical model of the carpo-metacarpal joint of the thumb
Introduction Of all hand joints, the thumb carpo-metacarpal (CMC) joint is the most vulnerable to degeneration by use, possibly ultimately requiring surgical intervention. This is a significant problem in an aging population. CMC joint vulnerability may relate to the recent evolutionary development of a fully opposable thumb unique to the human species, in which the CMC joint is key. The CMC is a saddle joint, and as such has a highly specific set of ligaments. However, the function and structure of these ligaments are still under debate. Also clinically, it has not been well established what harmful joint loads may result from failure of (one of) the ligaments by trauma or degenerative disease.
Objectives The objective is to improve understanding of the CMC joint ligament structure. To this end, ligaments in five anatomic specimens will be investigated and reconstructed in a 3D computer model. The bone geometries will be reconstructed from CT scans, including the marker frames by which the CMC joint motions in these specimens will be accurately measured by optical motion tracking. From this motion tracking, the centers of CMC rotation in these specimens will be determined. By dissection (performed by the supervisor), the CMC ligaments will be identified and measured, and mapped onto the 3D model. The congruence of the reconstructed ligaments and the experimentally measured motion will be used for sensitivity analysis and refinement of the anatomical mapping. The resulting models will be used for further study of CMC joint kinematics and load distributions with normal and defective ligaments.
Experience gained by the project The project will generate experiences in general biomechanics of hand control, and specifically in detailed ligament morphology, experimentally handling anatomical tissues, radiological reconstruction of bone surfaces, motion tracking, 3D biomechanical modeling, and preparing data for scientific publication in biomechanical journals.
Environment/materials/location The study will be executed at the Dept. of Bio, Electro and Mechanical Systems (BEAMS) of the Ecole Polytechnique of the Université Libre de Bruxelles (ULB), where the biomechanical testing will take place, in collaboration with the Depts. of Anatomy and Biomedical Engineering of UGent.