Radiologic Results of Three-Dimensional Templating for Total Shoulder Arthroplasty

BACKGROUND: The purpose of this study was to evaluate the radiologic results of total shoulder arthroplasty using computerized three-dimensional (3D) templating in preoperative planning. METHODS: Ten patients who underwent total shoulder arthroplasty using 3D templating preoperatively were enrolled in this study. A specialized computer program was used to reconstruct the 3D images of the shoulder from the computed tomographic images. The 3D images of various sizes of prostheses were used as the template in surgical planning of the shoulder arthroplasty. The size of the glenoid, humeral head, and stem measured in 3D templating were compared with those used in actual operation. Anatomical parameters, such as humeral head size, radius of curvature, and greater tuberosity to humeral head distance of the replaced shoulder, were measured and compared with those of the contralateral normal shoulder. RESULTS: The agreement rates between the glenoid size, head size, head thickness, and stem size estimated preoperatively by 3D templating and those measured in operation were 100%, 100%, 100%, and 80%, respectively. The difference in humeral head size, radius of curvature, and greater tuberosity to humeral head distance between the replaced shoulder and contralateral shoulder was 1.31 mm, 0.87 mm, and 1.17 mm, respectively. CONCLUSIONS: In total shoulder arthroplasty, 3D templating seems to enable accurate prediction of sizes of the prostheses to be inserted and thus replication of normal anatomy.