CT-Based Planning Improves Screw Placement Accuracy

Compared with conventional techniques for reverse shoulder arthroplasty, computed tomography (CT)-based preoperative planning and intraoperative navigation improved accuracy and precision for screw placement, as well as precision for baseplate positioning with respect to a predefined placement, according to study results.

Using a custom-designed system that allowed for CT-based preoperative planning, intraoperative navigation and postoperative evaluation, five orthopedic surgeons defined common preoperative plans on 3-D CT reconstructed cadaveric shoulders and performed three computer-assisted and three conventional simulated procedures. Queens University researchers in Ontario, Canada, digitally matched the 3-D CT reconstructed postoperative units to the preoperative model for evaluation of entry points, end points and angulations of screws and baseplate.

Results showed no difference between computer-assisted and conventional simulated procedures in accuracy or prevision of screws or baseplate entry points. However, the use of navigation for end points and angulations of three screws improved accuracy and precision, according to study results.

The data also found a trend of improvement in accuracy of the inferior score with navigation, as well as improvement in navigated baseplate end point precision, with a trend toward improved accuracy.