Reliability of 3-Dimensional Glenoid Component Templating and Correlation to Intraoperative Component Selection.

Although implant-specific intraoperative targeting devices for glenoid sizing exist, a validated method for preoperatively templating glenoid component size in primary total shoulder arthroplasty (TSA) based on digital imaging does not. We conducted a study to determine if 3-dimensional (3-D) digital imaging could be used for preoperative templating of glenoid component size and to compare templated glenoid sizes with implanted glenoid sizes. We created 3-D digital models from 3 glenoid component implant sizes and preoperative scapular computed tomography scans of 24 patients who underwent primary TSA. In study arm 1, surgeons templated the 3-D components using only 2 df (superior-inferior and anterior-posterior planes). In study arm 2, surgeons templated the 3-D components using 6 df (superior-inferior, anterior-posterior, and rotational planes). Overall intraobserver agreement was substantial (0.67) in study arm 1 (P < .001) and moderate (0.58) in study arm 2 (P < .001). In arm 1, overall interobserver agreement was fair (0.36) for trial 1 (P < .001) and fair (0.32) for trial 2 (P < .001). In arm 2, overall interobserver agreement was moderate (0.54) for trial 1 (P < .001) and moderate (0.43) for trial 2 (P < .001). In both arms, surgeons tended to template glenoid components smaller than those implanted intraoperatively, particularly for female patients. Our findings show that 3-D digital models can be consistently and reliably used for preoperative templating of glenoid com-ponent size.