The present and future of preoperative planning.

Preoperative planning for shoulder arthroplasty has become widely used for primary cases and now also in revision situations. From the initial, two-dimensional manual planning efforts on computed tomography scans, planning has evolved to now using three-dimensional planning software programs. A number of different programs exist with various methods underpinning their chosen landmarks and segmentation methods. Preoperative planning has allowed for development of execution tools to translate the preoperative plan to intraoperative reality. This article considers the particular relevance of preoperative arthroplasty planning to the shoulder joint, the current status of preoperative planning, the reasons to engage with preoperative planning, the execution tools available as an extension of preoperative planning, and the future of intraoperative execution technologies associated with planning. Preoperative planning is the foundation of prospective advances in these so-called enabling technologies and the future of preoperative planning will be shaped by a desire to continue to optimize execution techniques in shoulder arthroplasty, with the ultimate goal of using these techniques to achieve improved patient outcomes.