3-dimensional printing in shoulder surgery: Current literature and state of the art

3D printing technologies provide physical models of patient-specific anatomy for preoperative study, training and patient-specific instruments to improve accuracy and reproducibility during surgery. A literature review has been performed on principal fields of application of this technology in shoulder surgery. Anatomic models in shoulder surgery can improve understanding the spatial orientation in trauma surgery, and shoulder replacement, especially when degenerative conditions alter normal anatomy. Patient-specific models ensure a better understanding of anatomy by haptic feedback of the surgeon during the preoperative planning. In shoulder arthroplasty patient-specific guides seems to ensure high accuracy in the placement of glenoid component. Patient specific instruments improve reliability of components alignment and a good correlation with the preoperative planning. However, surgeon's double check remains essential for the whole procedure. Drawbacks of 3DP technologies remain limited access to 3D printers, long time to produce the models, and the absence of surrounding soft tissues. Anatomical models and patient-specific instruments seem to improve accuracy and reliability, improve preoperative planning and reduce intraoperative time, but whether this is correlated to a clinical benefit is unconfirmed and further clinical studies with long follow-up are necessary.