Related Experiment Video
Updated: Jun 15, 2025

Measuring 3D In-vivo Shoulder Kinematics using Biplanar Videoradiography
Published on: March 12, 2021
Analysis of trapeziometacarpal prosthesis cup position with respect to the trapezial anatomy
Kjell Van Royen1,2, Sebastiaan Bogaert1, Chul Ki Goorens3
1Department of Orthopaedics and Traumatology, UZ Brussel, Brussels, Belgium.
Abstract:
The purpose of this study was to analyse the anatomy of the trapezium with regard to cup position in trapeziometacarpal replacement and identify those trapeziums that are at risk of cup perforation through the trapezoid articular surface. The width of the proximal and distal articular surface and the height of the trapezium and second metacarpal facet were measured on 96 peritrapezial views reconstructed from computed tomography scans. The trapezoid articular surface of the trapezium (TRAST) angle was calculated, and four different cup designs were virtually positioned centrally in the trapezium and parallel to the proximal articular surface. Risk of perforation was defined as a cup that exceeds the ulnar border of the proximal articular surface. The mean TRAST angle in our study was 33°. Risk of perforation is higher when the second metacarpal facet is smaller than 5 mm and when the TRAST angle is 35° or more. In these cases, the position of the cup should be more radial or more distal.
Related Concept Videos
Functional Classification of Joints
The functional classification of joints is determined by the amount of mobility between the adjacent bones. Joints are functionally classified as a synarthrosis or immobile joint, an amphiarthrosis or slightly moveable joint, or as a diarthrosis, a freely moveable joint. Fibrous and cartilaginous joints can be functionally classified as either synarthroses or amphiarthroses, whereas all synovial joints are classified as diarthroses.
Synarthrosis
An...
Bones of the Upper Limb: Humerus
Space Trusses: Problem Solving
Consider a tripod consisting of a tetrahedral space truss with a ball-and-socket joint at C. Suppose the height and lengths of the horizontal and vertical...
Bones of the Upper Limb: Ulna
Bones of the Upper Limb: Radius
The radius has a nail-shaped head, and a...

