Prospects of 3D-printed sternum prostheses: a review
The stable yet dynamic reconstruction of large chest wall defects involving the sternum is a challenge. Titanium bars, mesh grafts, muscle and omentum flaps, methyl-methacrylate, and last but not least the implantation of sternal allografts from deceased donors are approaches for these operations. With the emerging 3D laser printing technique, a new era in surgery has begun, offering customized implants that were individually designed by using the patients CT scan as a template. Based on a PubMed literature review we compared 78 patients treated with the widely practiced standard techniques using titanium bars and mesh graft for sternal reconstruction to the first 11 cases reported using 3D-printed sternal prosthesis. We also took in seven cases with standardized sternum replacements made of Alumina ceramic and 19 patients after a sternal replacement with a cryopreserved allograft in the comparison, to include all treatment aspects. Each of the presented 3D-printed sternum replacements was designed differently as their creators put much thought in the best possible way of anchoring the adjacent rib stumps and allowing surrounding tissue to grow in easily. All of the patients who received a customized implant recovered quickly from the operation and complained of little impairment afterwards. The patients who were treated in the standard technique also received a stable and safe sternum replacement with little complications postoperatively. Since most of these patients were suffering from malignant diseases, there is a lack of long-term follow-up. With the first few cases with personalized 3D-printed sternum replacements we can only partially outline the scope and possibilities offered by this technique. Apart from obvious disadvantages regarding the production process, the new technique already seems by no means less effective in comparison to the standard procedures.