Accuracy of Patient-specific Jigs for Glenoid Component Positioning in Total Shoulder Arthroplasty

Controversy remains over complication rates in total shoulder replacement prostheses, often attributed to poor glenoid component positioning and fixation. Patient-specific jigs (PSJs) offer a potential tool for improvement in the accuracy of glenoid component placement in total shoulder arthroplasty, which may improve prosthesis longevity, functional outcomes, and reduce the need for revision. Preoperative computed tomography scans of 6 pairs of dissected human cadaveric scapulae were performed. Each pair had left and right scapulae randomized to the PSJ group (N=6) or the standard procedures group (N=6). Preoperative planning was completed using a 3-dimensional virtual system. PSJs were then tested against standard procedure. Postoperative computed tomography scans with the guide wire in situ were used to compare final guide wire position to the planned positions. The mean absolute inclination error was 1.4 degrees, mean absolute version error was 1.7 degrees and mean entry point error was 0.7 mm for the PSJ group. For the standard procedure group the mean absolute inclination error was 13.8 degrees, mean absolute version error was 3.2 degrees, and mean entry point error was 2.9 mm. Differences were significant for inclination (P=0.0013) and entry position (P=0.0002). Significantly more components were malpositioned in the standard procedure group than in the PSJ group (P=0.002). This randomized prospective pilot study demonstrated the accuracy and reproducibility of PSJs fo...

Source: Techniques in Shoulder and Elbow Surgery - January 30, 2018 Category: Orthopaedics Tags: Research Articles Source Type: research