Custom, 3-Dimensional Patient-Specific Instrumentation in Anatomic Total Shoulder Arthroplasty: Part 1dPreoperative Assessment, Preoperative Planning, and Guide Design

Successful total shoulder arthroplasty relies on a multitude of factors specific to patients, implant selection, and surgical technique. Among technical factors, correct intraoperative placement of prosthetic components is paramount. Three-dimensional computed tomography has emerged as a vital tool, allowing surgeons to measure glenoid inclination, glenoid version, and humeral head subluxation more accurately and reproducibly. Several commercial preoperative planning software resources are available to determine the optimal size and positioning of prosthetic components yet do so at significant cost and with meaningful time constraints. At our institution, we have applied the principles of these technologies to develop a custom, 3-dimensionally printed glenoid guide for accurate placement of the central pin. In this technical note, we describe our evaluation of patients with glenohumeral arthritis, as well as our step-by-step procedure for designing and printing a custom patient-specific instrumentation glenoid guide for anatomic total shoulder arthroplasty.