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RESEARCH ARTICLE
Structural design and multiphase biomechanical evaluation of a topology-optimized metal 3D-printed dual-compression plate for patellar fractures
Chi-Yang Liao1,2 ,
Shao-Fu Huang3,4 ,
Ya-Han Chan4 ,
Hsuan-Wen Wang3,4 ,
Yu-Pin Yang4 ,
Chun-Li Lin3,4*
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1 Department of Orthopedics, Tri-Service General Hospital Songshan Branch, National Defense Medical University, Taipei,
Taiwan
2 Department of Surgery, Tri-Service General Hospital Songshan Branch, National Defense Medical University, Taipei,
Taiwan
3 Department of Biomedical Engineering, Innovation & Translation Center of Medical Device, National Yang Ming Chiao Tung University, Taipei,
Taiwan
4 Department of Biomedical Engineering, National Yang Ming Chiao Tung University, Taipei,
Taiwan
IJB, 025480494 https://doi.org/10.36922/IJB025480494
Received: 25 November 2025 | Accepted: 26 December 2025 | Published online: 8 January 2026
(This article belongs to the Special Issue 3D Printing for Advancing Orthopedic Applications)
© 2026 by the Author(s). This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution 4.0 International License ( https://creativecommons.org/licenses/by/4.0/ )
Abstract
Patellar fractures, especially transverse and comminuted types, often present mechanical challenges that exceed the capabilities of conventional fixation constructs. This study develops a topology-optimized metal three-dimensional-printed dual-compression patellar plate designed to improve fragment stability while maintaining appropriate intraoperative rigidity. The plate design was first refined using an original anatomically assembled thin bone plate, which underwent finite element analysis and topology optimization to preserve primary load-bearing paths and reduce excessive stiffness. The optimized structure was subsequently fabricated using selective laser melting with Ti-6Al-4V and mechanically evaluated in accordance with American Society for Testing and Materials F382 standards. Static four-point bending tests demonstrated a proof load (P) of 257.31 ± 5.40 N and structural bending stiffness of 1.10 ± 0.01 N·m². Fatigue testing revealed runout at 15% P, while failure occurred at higher load levels (25% P & 30% P), revealing two distinct modes: plate fracture at topology-optimized transition zones and locking-screw shear failure. Static tensile testing revealed that dual-compression fixation significantly (p<0.05) enhanced load-bearing capacity compared with single-compression fixation for both C1 (712 N vs. 517.5 N) and C3 (253.75 N vs. 205.25 N) fracture models. Dynamic knee-extension testing demonstrated that dual compression markedly reduced medial–lateral fracture micromotion, decreasing C3 gaps from 0.348–0.534 mm to 0.078–0.107 mm without increasing quadriceps reaction force. Overall, the topology-optimized dual-compression patellar plate provides mechanically validated interfragmentary stability, effective micromotion control, and a well-defined fatigue performance envelope, supporting its potential as an advanced fixation solution for clinically challenging patellar fractures.
Graphical abstract
Keywords
Biomechanics
Dynamic tests
Four-point bending
Patella
Three-dimensional printing
Funding
This study is supported in part by NSTC project 113-2622- E-A49 -027 and 114-2923-E-A49 -014 -MY2 Taiwan.
Conflict of interest
No potential conflict of interest was reported by the author(s).
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