Schematic overview of the workflow employed for statistical shape analysis of the trapeziometacarpal joint.

Schematic overview of the workflow employed for statistical shape analysis of the trapeziometacarpal joint. A training set of CT images of healthy and osteoarthritic joints (A) were manually segmented to produce a triangulated mesh (B). Vertices of a representative triangulated mesh were extracted as a point cloud on which a parametric template mesh (C) was created. The template mesh was fitted to all point clouds in an iterative fitting process (D). The principal components of variation were determined (E). Linear discriminant analysis (LDA) was performed on the principal component weights to classify between healthy and OA joints (F). LDA reconstructions of healthy and early osteoarthritic (EOA) TMC joint bones were generated and overlaid, and absolute pointwise distance maps were calculated and visualised.