Design, additive manufacture and clinical application of a patient-specific titanium implant to anatomically reconstruct a large chest wall defect

Purpose Chest wall reconstruction of large oncological defects following resection is challenging. Traditional management involves the use of different materials that surgeons creatively shape intraoperatively to restore the excised anatomy. This is time-consuming, difficult to mould into shape and causes some complications such as dislocation or paradoxical movement. This study aims to present the development and clinical implantation of a novel custom-made three-dimensional (3D) laser melting titanium alloy implant that reconstructs a large chest wall resection and maintains the integrity of the thoracic cage. Design/methodology/approach The whole development process of the novel implant is described: design specifications, computed tomography (CT) scan manipulation, 3D computer-assisted design (CAD), rapid prototyping, final manufacture and clinical implantation. A multidisciplinary collaboration in between engineers and surgeons guided the iterative design process. Findings The implant provided excellent aesthetical and functional results. The virtual planning and production of the implant prior to surgery reduced surgery time and uncertainty. It also improved safety and accuracy. The implant sited nicely on the patient anatomy after resection following the virtual plan. At six months following implantation, there were no implant-related complications of pain, infection, dislocation or paradoxical movement. This technique offered a fast lead-time for implant production, which is crucial for oncological treatment. Research limitations/implications More cases and a long-term follow-up are needed to confirm and quantify the benefits of this procedure; further research is also required to design a solution that better mimics the chest wall biomechanics while preventing implant complications. Originality/value The authors present a novel custom thoracic implant that provided a satisfactory reconstruction of a large chest wall defect, developed and implanted within three weeks to address a fast-growing chondrosarcoma. Furthermore, the authors describe its development process in detail as a design guideline, discussing potential improvements and critical design considerations so that this study can be replicated for future cases.

Download Full-text

Chest wall reconstruction with an anatomically designed 3-D printed titanium ribs and hemi-sternum implant

3D Printing in Medicine ◽

10.1186/s41205-020-00079-0 ◽

2020 ◽

Vol 6 (1) ◽

Author(s):

Ira Goldsmith ◽

Peter Llewelyn Evans ◽

Heather Goodrum ◽

James Warbrick-Smith ◽

Thomas Bragg

Keyword(s):

Titanium Alloy ◽

Chest Wall ◽

Computer Aided Design ◽

Extent Of Resection ◽

Patient Specific ◽

Chest Wall Resection ◽

Soft Tissue Reconstruction ◽

Large Defect ◽

Paradoxical Movement ◽

Custom Made

Abstract Background Chest wall resection following wide local excision for bone tumor results in a large defect. Reconstructing this defect is complex and requires skeletal and soft tissue reconstruction. We describe the reconstruction of a large skeletal defect with a three-dimensional (3-D) printed custom-made, anatomically designed, titanium alloy ribs and hemi-sternum implant. Method To design the implant manual bone threshold segmentation was performed to create a 3-D virtual model of the patient’s chest and the tumor from sub-millimeter slice computed tomography (CT) scan data. We estimated the extent of resection needed to ensure tumor-free margins by growing the tumor by two cm all around.. We designed the implant using an anatomical image of the ribs and right hemi-sternum and then fabricated a 3D model of them in titanium metal using TiMG 1 powder bed fusion technology. At surgery the implant was slotted into the defect and sutured to the ribs laterally and hemi-sternum medially. Results Histology confirmed clear all around microscopic margins. Following surgery and at 18 month follow up the patient was asymptomatic with preserved quality of life and described no pain, localized tenderness or breathlessness. There was no displacement or paradoxical movement of the implant. Conclusion Our techniques of CT segmentation, editing, computer aided design of the implant and fabrication using laser printing of a custom-made anatomical titanium alloy chest wall ribs and hemi-sternum for reconstruction is feasible, safe and provides a satisfactory result. Hence, a patient specific 3-D printed titanium chest wall implant is another useful adjunct to the surgical approach for reconstructing large chest wall defects whilst preserving the anatomical shape, structure and function of the thorax.

Download Full-text

Computer-aided methods for single-stage fibrous dysplasia excision and reconstruction in the zygomatico-orbital complex

Rapid Prototyping Journal ◽

10.1108/rpj-05-2018-0116 ◽

2019 ◽

Vol 25 (4) ◽

pp. 728-737 ◽

Cited By ~ 1

Author(s):

Igor Budak ◽

Aleksandar Kiralj ◽

Mario Sokac ◽

Zeljko Santosi ◽

Dominic Eggbeer ◽

...

Keyword(s):

Fibrous Dysplasia ◽

Single Stage ◽

Successful Outcome ◽

Patient Specific ◽

Additive Manufacture ◽

Maximum Deviation ◽

Design Guideline ◽

Design Decisions ◽

Content Type ◽

Computer Aided

Purpose Computer-aided design and additive manufacture (CAD/AM) technologies are sufficiently refined and meet the necessary regulatory requirements for routine incorporation into the medical field, with long-standing application in surgeries of the maxillofacial and craniofacial regions. They have resulted in better medical care for patients and faster, more accurate procedures. Despite ever-growing evidence about the advantages of computer-aided planning, CAD and AM in surgery, detailed reporting on critical design decisions that enable methodological replication and the development and establishment of guidelines to ensure safety are limited. This paper aims to present a novel application of CAD and AM to a single-stage resection and reconstruction of fibrous dysplasia in the zygoma and orbit. Design/methodology/approach It is reported in sufficient fidelity to permit methods replication and design guideline developments in future cases, wherever they occur in the world. The collaborative approach included engineers, designers, surgeons and prosthetists to design patient-specific cutting guides and a custom implant. An iterative design process was used, until the desired shape and function were achieved, for both of the devices. The surgery followed the CAD plan precisely and without problems. Immediate post-operative subjective clinical judgements were of an excellent result. Findings At 19 months post-op, a CT scan was undertaken to verify the clinical and technical outcomes. Dimensional analysis showed maximum deviation of 4.73 mm from the plan to the result, while CAD-Inspection showed that the deviations ranged between −0.1 and −0.8 mm and that the majority of deviations were located around −0.3 mm. Originality/value Improvements are suggested and conclusions drawn regarding the design decisions considered critical to a successful outcome for this type of procedure in the future.

Download Full-text