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.
Keywords: 3-D printed titanium implant; Chest wall reconstruction; Chest wall resection; Chondroscarcoma.