Toward a Population-Informed Framework for Structural Assessment of 3D-Printed Prosthetic Sockets

Structural assessment of customized 3D-printed prosthetic sockets requires a basis for selecting geometries and loading relevant socket regions. This study explored a population-informed assessment framework combining statistical shape sampling with mock limb material comparisons. A statistical shape model (SSM) was reconstructed from 67 archived records of liner-covered residual limbs. Geometries at the empirical 2.5th, 50th, and 97.5th percentiles of the first principal component guided socket design; mock limbs matched the socket inner surfaces. Nine finite element cases compared aluminum, a muscle-inspired surrogate, and a bulk soft-tissue surrogate under 4480 N loading based on ISO 10328 condition I at level P5. At the 2.5th, 50th, and 97.5th percentiles, trimline maxima were 1.0, 1.5, and 0.7 MPa for aluminum; 16.0, 12.4, and 3.9 MPa for the muscle-inspired surrogate; and 19.7, 14.1, and 3.9 MPa for the bulk surrogate. Whole-socket peaks shifted from the distal attachment with aluminum to the anterior trimline with compliant surrogates in two geometries; all materials produced distal peaks in the 97.5th-percentile geometry. These findings support combining patient-derived shape sampling with explicit mock limb specification for regional socket assessment. Shape percentiles describe observed variation rather than worst-case strength conditions. The framework may inform complementary test configurations, but failure prediction and product assurance require broader assessment and physical validation.