Custom design and biomechanical clinical trials of 3D‐printed polyether ether ketone femoral shaft prosthesis

Abstract

During the surgical resection and reconstruction of a pathological femoral fracture, the removal of the femoral tumor leaves a large bone defect. Thus, it is necessary to reconstruct the defect and perform internal fixation. Polyether ether ketone (PEEK) has been widely used in spinal fusion and cranioplasty given its excellent biomechanical properties, biocompatibility, and stability. The typical design method of femoral prosthesis is based on the contralateral mirror image model (M-model), and we propose a novel method for designing femoral prosthesis, which is based on the cross section and centerline of the mirrored femur (C-model). In this study, the femoral shaft prostheses based on two models were manufactured using fused deposition modeling technology, and we use mechanical test and finite element analysis (FEA) to reveal the differences in mechanical properties of the two models. The mechanical results showed that the maximum loading force and yield strength were increased by 3% and 6% in the C-model prosthesis compared with the M-model prosthesis, respectively. In FEA, the results indicate that the C-model prosthesis could reduce the stress concentration by 5.4%-10.9% compared to the M-model prosthesis.Finally, the 3D-printed PEEK femoral shaft prosthesis based on C-model was implanted, no early complications occurred. Postoperative radiological examination indicated that the prosthesis and the femoral osteotomy end were closely matched and fixed well.

Mechanical Distribution and New Bone Regeneration After Implanting 3D Printed Prostheses for Repairing Metaphyseal Bone Defects: A Finite Element Analysis and Prospective Clinical Study

“…Besides, studies have demonstrated that when applying a vertical load to simulate the early postoperative internal fixation load-bearing, the stress is mainly concentrated in the middle of the IM nail (Chen et al, 2018;Wang et al, 2020). Wu et al (2022) applied the 3D printed polyether ether ketone prosthesis to repair the femoral shaft defect and observed middle-concentrated stress of the IM nail. As shown by the FEA results in the present study, when the interlocking IM nail was applied to stabilize prostheses for metaphyseal bone defects, the stress was mainly distributed along the IM nail (the maximum stress concentration occurred at the middle of the nail) (Figure 4), which is consistent with previous studies.…”

Influence of different fixation modes on biomechanical conduction of 3D printed prostheses for treating critical diaphyseal defects of lower limbs: A finite element study

“…However, the addition of the lateral wing did not significantly affect the stress concentration characteristics of the IM nail when by comparing Mode I and Mode IV. In a previous study, Wu et al applied a 3D printed polyether ether ketone prosthesis to repair the femoral shaft defect and observed that the stress was concentrated in the middle ( 23 ). Similarly, when an IM is used to fix long bone fractures, the stress can also be effectively transmitted and concentrated mainly in the middle region of the IM nail, which could help increase the mechanical stability and reduce stress shielding ( 26 , 27 ).…”

“…FEA has been applied to evaluate and compare the biomechanical characteristics in prosthesis design and stem fixation (E,F,G) ( 17 – 19 ).In terms of the design of 3D printed prostheses, FEA has also been applied to analyze biomechanical performance and stress distribution ( 20 – 22 ), and predict the bone-implant interface stress. Wu et al applied FEA to compare the differences in the mechanical properties of two prosthesis model and successfully designed a 3D printed polyether ether ketone femoral shaft prosthesis for repairing critical bone defects ( 23 ). These results have laid a foundation for the development of this study.…”

The Year 2022 in biomaterials research: A perspective from the editors of six leading journals

“…These works have investigated the range of 3D printing from electron-beam printing of titaniumbased spinal cages 91 to 3D printing of Hydroxyapatite and/or polymeric hydrogel biomaterials. Three-dimensional printing of gelatinbased hydrogels 92,93 for bone and cartilage applications was reported as were printed PEEK hip stems 94 and hydroxyapatite-based biomaterials. 95 Many other topics were covered in JBMR B in the past year and no review can possibly cover all that was accomplished.…”